POLYURETHANE FIBERS AND METHODS OF MAKING THE SAME

REFERENCE TO SEQUENCE LISTING SUBMITTED ELECTRONICALLY

[0001] The content of the electronically submitted sequence listing in XML file (Name:

4431 084PC01_Seqlisting_ST26.xml; Size: 2,709 bytes; and Date of Creation: April 10, 2023) filed with the application is incorporated herein by reference in its entirety.

FIELD

[0002] This disclosure relates to polyurethane fibers. In some embodiments, the polyurethane fibers can be wet-spun polyurethane fibers. In some embodiments, the polyurethane fibers can comprise a protein polyurethane alloy comprising one or more proteins dissolved in a polyurethane. In some embodiments, the fibers can be used to make a textile or fabric article, for example, a textile or fabric article typically prepared from natural leather.

BACKGROUND

[0003] Leather is a versatile product used across many industries, including the furniture industry, where leather is regularly used as upholstery, the clothing industry, where leather is used to manufacture pants and jackets, the shoe industry, where leather is used to prepare casual and dress shoes, the luggage industry, the handbag and accessory industry, and in the automotive industry. The global trade value for leather is high, and there is a continuing and increasing demand for leather products. Despite leather’s seeming ubiquity, there are variety of costs, constraints, and social concerns associated with producing natural leather. Foremost, natural leathers are produced from animal skins, and as such, require raising and slaughtering livestock. Raising livestock requires enormous amounts of feed, pastureland, water, and fossil fuels, and contributes to air and waterway pollution through, for example, greenhouse gases like methane. Leather production also raises social concerns related to the treatment of animals. In recent years, there has also been a fairly well documented decrease in the availability of traditional high quality hides. For at least these reasons, alternative means to meet the demand for leather are desirable. [0004] Further, other fabric materials, such as cotton and spandex, are used across many industries, including the furniture industry and the clothing industry. The demand for such fabric materials is high and there is a continuing need for improved fabric materials.

BRIEF SUMMARY

[0005] The present disclosure provides polyurethane fibers suitable for use in a variety of applications, including textile and fabric applications. In some embodiments, the fibers can comprise a protein polyurethane alloy that provides the fibers with desirable properties for use in a vari ety of applications.

[0006] A first embodiment (1) of the present disclosure is directed to a protein polyurethane alloy construct comprising a protein dissolved within a polyurethane, wherein the construct is in the form of a fiber, and wherein a core of the fiber is defined by the protein polyurethane alloy.

[0007] In a second embodiment (2), the fiber according to the first embodiment (1) is a wet-spun fiber.

[0008] In a third embodiment (3), the protein according to the first embodiment (1) or the second embodiment (2) is selected from the group consisting of: soy protein, collagen, gelatin, bovine serum albumin, pea protein, egg white albumin, casein protein, peanut protein, edestin protein, whey protein, karanja protein, hemp protein, an enzyme, and cellulase.

[0009] In a fourth embodiment (4), the protein according to the first embodiment (1) or the second embodiment (2) is a soy protein.

[0010] In a fifth embodiment (5), the soy protein according to the fourth embodiment (4) is soy protein isolate.

[0011] In a sixth embodiment (6), the protein polyurethane alloy construct according to any one of embodiments (1) - (5 ) further comprises a dye.

[0012] In a seventh embodiment (7), the fiber according to any one of embodiments (1) -

(6) has a length of greater than or equal to about 5 millimeters.

[0013] In an eighth embodiment (8), the fiber according to any one of embodiments (1) -

(7) has an effective diameter ranging from about 1 micrometer to about 1 centimeter. [0014] In a ninth embodiment (9), the fiber according to any one of embodiments (1) -

(8) has an aspect ratio of greater than or equal to about 10, the aspect ratio defined as the ratio of a length of the fiber to an effective diameter of the fiber.

[0015] In a tenth embodiment (10), the aspect ratio according to the ninth embodiment

(9) ranges from about 10 to about 1000.

[0016] In an eleventh embodiment (11), the fiber according to any one of embodiments (1) --- (10) has a modulus of greater than or equal to about 0.1 cN/tex.

[0017] In a twelfth embodiment (12), the fiber according to any one of embodiments (1)

- (10) has a modulus ranging from about 0.1 cN/tex to about 10 cN/tex.

[0018] In a thirteenth, embodiment (13), the fiber according to any one of embodiments (1) - (12) has a maximum elongation of greater than or equal to about 100%.

[0019] In a fourteenth embodiment (14), the fiber according to any one of embodiments (1) - (12) has a maximum elongation ranging from about 100% to about 1000%.

[0020] In a fifteenth embodiment (15), the fiber according to any one of embodiments (1)

- (14) has a tenacity of greater than or equal to about 1 cN/tex.

[0021] In a sixteenth embodiment, the fiber according to any one of embodiments (1) - (14) has a tenacity ranging from about 1 cN/tex to about 20 cN/tex.

[0022] In a seventeenth embodiment (17), the protein polyurethane alloy construct according to any one of embodiments (1) - (16) comprises a dye and a dye penetration greater than or equal to about 5% of an effective radius of the fiber.

[0023] In an eighteenth embodiment (18), the dye penetration according to the seventeenth embodiment (17) is greater than or equal to about 50% of the effective radius of the fiber.

[0024] In a nineteenth embodiment (19), the dye penetration according to the seventeenth embodiment (17) is greater than or equal to about 90% of the effective radius of the fiber.

[0025] In a twentieth embodiment (20), the polyurethane according to any one of embodiments (1) - (19) comprises a polyol component selected from the group consisting of: a poly ether polyol, a polyester polyol, a polycarbonate polyol, and a combination thereof.

[0026] A twentieth-first embodiment (21) of the present disclosure is directed to a fiber bundle comprising a plurality of the protein polyurethane alloy constructs according to any one of embodiments (1) - (20). [0027] A twenty-second embodiment (22) of the present disclosure is directed to a method of making a protein polyurethane alloy fiber, the method comprising extruding a blended mixture into a protein polyurethane alloy fiber, the blended mixture comprising a protein dissolved within a polyurethane and an organic solvent.

[0028] In a twenty-third embodiment (23), the method according to the twenty-second embodiment (22) comprises blending the protein with a polyurethane in an aqueous solution to form the blended mixture comprising the protein dissolved within the polyurethane, and adding the organic solvent to the blended mixture.

[0029] In a twenty-fourth embodiment (24), extruding the blended mixture into the protein polyurethane alloy fiber according to the twenty-second embodiment (22) or the twenty-third embodiment (23) comprises wet spinning the blended mixture.

[0030] In a twenty-fifth embodiment (25), the organic solvent according to any one of embodiments (21) - (24) is an ether-containing solvent or an ester-containing solvent.

[0031] In a twenty-sixth embodiment (26), the organic solvent according to the twentyfifth embodiment (25) is an ether-containing solvent and the ether-containing solvent is tetrahydrofuran.

[0032] In a twenty-seventh embodiment (27), the organic solvent according to the twenty-fifth embodiment (25) is an ether-containing solvent and the ether-containing solvent is diethyl ether.

[0033] In a twenty-eighth embodiment (28), the organic solvent according to the twentyfifth embodiment (25) is an ether-containing solvent and the ether-containing solvent is a polyether.

[0034] In a twenty-ninth embodiment (29), the organic solvent according to the twentyfifth embodiment is an ester-containing solvent and the ester-containing solvent is butyl acetate.

[0035] In a thirtieth embodiment (30), the blended mixture according to any one of embodiments (22) - (29) further comprises a dye.

[0036] In a thirty-first embodiment (31), the method according to any one of embodiments (22) - (29) or embodiments (22) - (30) further comprises dyeing the protein polyurethane alloy fiber.

[0037] In a thirty-second embodiment (32), the polyurethane according to any one of embodiments (22) -- (31) is a water-dispersible polyurethane. [0038] In a thirty-third embodiment (33), the polyurethane according to any one of embodiments (22) - (32) comprises a polyol component selected from the group consisting of: a polyether polyol, a polyester polyol, a polycarbonate polyol, and a combination thereof.

[0039] A thirty-fourth embodiment (34) of the present disclosure is directed to a method of wet spinning a polyurethane fiber, the method comprising blending a water-dispersible polyurethane and an organic solvent to form a blended mixture, and wet spinning the blended mixture to form a polyurethane fiber.

[0040] In a thirty-fifth embodiment (35), the polyurethane fiber according to the thirtyfourth embodiment (34) is substantially free of protein.

[0041] In a thirty-sixth embodiment (36), the organic solvent according to the thirtyfourth embodiment (34) or the thirty-fifth embodiment (35) is an ether-containing solvent or an ester-containing solvent.

[0042] In a thirty-seventh embodiment (37), the organic solvent according to the thirtysixth embodiment (36) is an ether-containing solvent and the ether-containing solvent is tetrahydrofuran.

[0043] In a thirty-eighth embodiment (38), the organic solvent according to the thirtysixth embodiment (36) is an ether-containing solvent and the ether-containing solvent is diethyl ether.

[0044] In a thirty-ninth embodiment (36), the organic solvent according to the thirty-sixth embodiment (36) is an ether-containing solvent and the ether-containing solvent is a polyether.

[0045] In a fortieth embodiment (40), the organic solvent according to the thirty-sixth embodiment (36) is an ester-containing solvent and the ester-containing solvent is butyl acetate.

[0046] In a forty-first embodiment (41), the blended mixture according to any one of embodiments (34) - (40) further comprises a dye.

[0047] In a forty-second embodiment (42), the method according to any one of embodiments (34) - (40) or embodiments (34) - (41) further comprises dyeing the polyurethane fiber.

[0048] In a forty-third embodiment (43), the polyurethane fiber according to any one of embodiments (34) -- (42) has a length of greater than or equal to about 5 millimeters. [0049] In a forty-fourth embodiment (44), the polyurethane fiber according to any one of embodiments (34) - (43) has a modulus of greater than or equal to about 0. 1 cN/tex.

[0050] In a forty-fifth embodiment (45), the polyurethane fiber according to any one of embodiments (34) - (44) has a maximum elongation of greater than or equal to about 100%.

[0051] In a forty-sixth embodiment (46), the polyurethane fiber according to any one of embodiments (34) --- (45) has a tenacity of greater than or equal to about 1 cN/tex.

[0052] A forty-seventh embodiment (47) of the present disclosure is directed to a method of making a protein polyurethane alloy fiber, the method comprising extruding a blended mixture into a protein polyurethane alloy fiber, the blended mixture comprising a protein dissolved within a polyurethane and an aqueous polyethylene oxide solution.

[0053] In a forty-eighth embodiment (48), the method according to the forty-seventh embodiment (47) comprises blending the protein with a polyurethane in an aqueous solution to form the blended mixture comprising the protein dissolved within the polyurethane, and adding the aqueous polyethylene oxide solution to the blended mixture.

[0054] In a forty-ninth embodiment (49), extruding the blended mixture into the protein polyurethane alloy fiber according to the forty-seventh embodiment (47) or the fortyeighth embodiment (48) comprises wet spinning the blended mixture.

[0055] In a fiftieth embodiment (50), the blended mixture according to any one of embodiments (47) - (49) further comprises a dye.

[0056] In fifty-first embodiment (51), the method according to any one of embodiments (47) - (49) or embodiments (47) - (50) further comprises dyeing the protein polyurethane alloy fiber.

[0057] In a fifty-second embodiment (52), the polyurethane according to any one of embodiments (447) - (51) is a water-dispersible polyurethane.

[0058] A fifty-third embodiment (53) of the present disclosure is directed to a method of wet spinning a polyurethane fiber, the method comprising blending a water-dispersible polyurethane and an aqueous polyethylene oxide solution to form a blended mixture, and wet spinning the blended mixture to form a polyurethane fiber.

[0059] In a fifty-fourth embodiment (54), the polyurethane fiber according to the fifty- third embodiment (53) is substantially free of protein.

[0060] In a fifty-fifth embodiment (55), the blended mixture according to the fifty -third embodiment (53) or the fifty-fourth embodiment (54) further comprises a dye. [0061] In a fifty-sixth embodiment (56), the method according to the fifty-third embodiment (53), the fifty-fourth embodiment (54), or any one of embodiments (53) - (55) further comprises dyeing the polyurethane fiber.

[0062] In a fifty-seventh embodiment (57), the polyurethane fiber according to any one of embodiment (53) -- (56) has a length of greater than or equal to about 5 millimeters.

[0063] In a fifty-eighth embodiment (58), the polyurethane fiber according to any one of embodiments (53) -- (57) has a modulus of greater than or equal to about 0.1 cN/tex.

[0064] In a fifty-ninth embodiment (59), the polyurethane fiber according to any one of embodiments (53) - (58) has a maximum elongation of greater than or equal to about 100%.

[0065] In a sixtieth embodiment (60), the polyurethane fiber according to any one of embodiments (53) -- (59) has a tenacity of greater than or equal to about 1 cN/tex.

BRIEF DESCRIPTION OF THE FIGURES

[0066] The accompanying figures, which are incorporated herein, form part of the specification and illustrate embodiments of the present disclosure. Together with the description, the figures further serve to explain the principles of and to enable a person skilled in the relevant art(s) to make and use the disclosed embodiments. These figures are intended to be illustrative, not limiting. Although the disclosure is generally described in the context of these embodiments, it should be understood that it is not intended to limit the scope of the disclosure to these particular embodiments. In the drawings, like reference numbers indicate identical or functionally similar elements.

[0067] FIG. 1 illustrates a fiber according to some embodiments.

[0068] FIG. 2 illustrates a cross section of a fiber according to some embodiments along the line 2 - 2’ in FIG. 1.

[0069] FIG. 3 illustrate a fiber bundle according to some embodiments.

DETAILED DESCRIPTION

[0070] The indefinite articles “a,” “an,” and “the” include plural referents unless clearly contradicted or the context clearly dictates otherwise.

[0071] The term “comprising” is an open-ended transitional phrase. A list of elements following the transitional phrase “comprising” is a non-exclusive list, such that elements in addition to those specifically recited in the list can also be present. The phrase “consisting essentially of’ limits the composition of a component to the specified materials and those that do not materially affect the basic and novel characteristic(s) of the component. The phrase “consisting of’ limits the composition of a component to the specified materials and excludes any material not specified.

[0072] Where a range of numerical values comprising upper and lower values is recited herein, unless otherwise stated in specific circumstances, the range is intended to include the endpoints thereof, and all integers and fractions within the range. It is not intended that the disclosure or claims be limited to the specific values recited when defining a range. Further, when an amount, concentration, or other value or parameter is given as a range, one or more ranges, or as list of upper values and lower values, this is to be understood as specifically disclosing all ranges formed from any pair of any upper range limit or value and any lower range limit or value, regardless of whether such pairs are separately disclosed. Finally, when the term “about” is used in describing a value or an end-point of a range, the disclosure should be understood to include the specific value or end-point referred to. Whether or not a numerical value or end-point of a range recites “about,” the numerical value or end-point of a range is intended to include two embodiments: one modified by “about,” and one not modified by “about.”

[0073] As used herein, the term “about” refers to a value that is within ± 10% of the value stated. For example, about 3 MPa can include any number between 2.7 MPa and 3.3 MPa. That said, if a percentage is listed and the value of that percentage cannot go above 100%, for example 100 wt% or 99 wt%, “about” does not modify the percentage to include values over 100%.

[0074] As used herein, a “bio-based polyurethane” is a polyurethane where at least a part of the polyurethane, for example the building blocks of polyols, such as diols and diacids like succinic acid, are derived from a biological material such as corn starch.

[0075] As used herein, the term “substantially free of’ means that a component is present in a detectable amount not exceeding about 0.1 wt%.

[0076] As used herein, the term “free of” means that a component is not present in a blend or material (e.g., a protein polyurethane alloy), even in trace amounts.

[0077] As used herein “collagen” refers to the family of at least 28 distinct naturally occurring collagen types including, but not limited to collagen types I, II, III, IV, V, VI, VII, VIII, IX, X, XI, XII, XIII, XIV, XV, XVI, XVII, XVIII, XIX, and XX. The term collagen as used herein also refers to collagen prepared using recombinant techniques. The term collagen includes collagen, collagen fragments, collagen-like proteins, triple helical collagen, alpha chains, monomers, gelatin, trimers and combinations thereof. Recombinant expression of collagen and collagen-like proteins is known in the art (see, e.g., Bell, EP 1232182B1, Bovine collagen and method for producing recombinant gelatin; Olsen, et al.. U.S. Patent No. 6,428,978 and VanHeerde, et al.. U.S. Patent No. 8,188,230, incorporated by reference herein in their entireties) Unless otherwise specified, collagen of any type, whether naturally occurring or prepared using recombinant techniques, can be used in any of the embodiments described herein. That said, in some embodiments, the collagen described herein can be prepared using bovine Type I collagen. Collagens are characterized by a repeating triplet of amino acids, -(Gly-X-Y)n-, so that approximately one-third of the amino acid residues in collagen are glycine. X is often proline and Y is often hydroxyproline. Thus, the structure of collagen may consist of three intertwined peptide chains of differing lengths. Different animals may produce different amino acid compositions of the collagen, which may result in different properties (and differences in the resulting leather).

[0078] Any type of collagen, truncated collagen, unmodified or post-translationally modified, or amino acid sequence-modifi ed collagen can be used as part of the protein polyurethane alloy.

[0079] In some embodiments, the collagen can be plant-based collagen. For example, the collagen can be a plant-based collagen made by CollPlant.

[0080] In some embodiments, a collagen solution can be fibrillated into collagen fibrils. As used herein, collagen fibrils refer to nanofibers composed of tropocollagen or tropocollagen-like structures (which have a triple helical structure). In some embodiments, triple helical collagen can be fibrillated to form nanofibrils of collagen.

[0081] In some embodiments, a recombinant collagen can comprise a collagen fragment of the amino acid sequence of a native collagen molecule capable of forming tropocollagen (trimeric collagen). A recombinant collagen can also comprise a modified collagen or truncated collagen having an amino acid sequence at least 70, 80, 90, 95, 96, 97, 98, or 99% identical or similar to a native collagen amino acid sequence (or to a fibril forming region thereof or to a segment substantially comprising [Gly-X-Y]n). In some embodiments, the collagen fragment can be a 50 kDa portion of a native collagen. Native collagen sequences include the amino acid sequences of CollAl, CollA2, and Col3 Al, described by Accession Nos. NP__001029211.1, NP__776945.1 and NP__001070299.1, which are incorporated by reference. In some embodiments, the collagen fragment can be a portion of human collagen alpha-l(III) (Col3Al; Uniprot # P02461, Entrez Gene ID # 1281).

[0082] In some embodiments, the collagen fragment can have the amino acid sequence listed as SEQ ID NO: 1. In some embodiments, the collagen fragment can have at least about 80%, at least about 85%, at least about 87.5%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99% or 100% sequence identity, or similarity to SEQ ID NO: 1.

[0083] Methods of producing recombinant collagen and recombinant collagen fragments are known in the art. For example, U.S. Pub. Nos. 2019/0002893, 2019/0040400, 2019/0093116, and 2019/0092838 provide methods for producing collagen and collagen fragments that can be used to produce the recombinant collagen and recombinant collagen fragments disclosed herein. The contents of these four publications are incorporated by reference in their entirety.

[0084] As used herein, a “fiber” refers to a construct having a length that is substantially larger than its effective diameter. A “fiber” may be a filament, a thread, a yarn, a cable, a cord, a fiber tow, a tape, a ribbon, a monofilament, a braid, a string, or any other form of material that can be spooled. In some embodiments, a fiber can have a length that is at least ten times larger than its effective diameter. In some embodiments, a fiber can have a length that is at least 100 times larger than its effective diameter. In some embodiments, a fiber can have a length that is at least 200 times larger than its effective diameter. In some embodiments, a fiber can have a length that is at least 300 times larger than its effective diameter. In some embodiments, a fiber can have a length that is at least 500 times larger than its effective diameter.

[0085] An “effective diameter” is used herein to describe the diameter of a fiber, but this term should not be interpreted as requiring a fiber to have a circular diameter or shape. Instead, a fiber can have a non-circular shape, and in such embodiments, the term “effective diameter” is intended to refer to the maximum cross-sectional dimension of the shape. For example, the “effective diameter” of a fiber having an elliptical cross-sectional shape would be the length of the major axis of the elliptical shape. For a fiber having an effective diameter that varies along the length of the fiber, the effective diameter is the largest effective diameter. An “effective radius” is defined as half of the fiber’s effective diameter.

[0086] As used herein, the term “core” and the phrase “core of the fiber” means a region of the fiber located along the cross-sectional center of the fiber. Unless specified otherwise, the region of the fiber located along the cross-sectional center of the fiber is the region having a cross-sectional center defined by the cross-sectional center of the fiber and having an effective diameter less than or equal to 50% of the effective diameter of the fiber. In some embodiments, the region of the fiber located along the cross- sectional center of the fiber can be the region having a cross-sectional center defined by the cross-sectional center of the fiber and having an effective diameter less than or equal to 20% of the effective diameter of the fiber. In some embodiments, the region of the fiber located along the cross-sectional center of the fiber can be the region having a cross- sectional center defined by the cross-sectional center of the fiber and having an effective diameter of less than or equal to 10% of the effective diameter of the fiber.

[0087] As used herein, the term “wet spinning” refers to a process of making fibers comprising mixing a waterborne polymer dispersion, and optionally a protein, in a suitable solvent to create a polymer mixture (or polymer protein mixture) and extruding the polymer or polymer protein mixture through a needle or spinneret into a liquid coagulation bath where the polymer or polymer protein mixture coagulates to form a fiber.

[0088] As used herein, the term “wet-spun fiber” refers to a fiber made using wet spinning.

[0089] As used herein, the term “dye penetration” means the distance from the exterior surface of a fiber where a dye is visibly present in a cross-section of the fiber under an optical microscope. Unless specified otherwise, dye penetration is measured in a direction perpendicular to a point on the exterior surface.

[0090] Polyurethane fibers described herein are extruded polyurethane fibers comprising one or more polyurethanes. In some embodiments, the extaided polyurethane fibers described herein are wet-spun polyurethane fibers comprising one or more polyurethanes. In some embodiments, the wet-spun fibers can be spun from a polyurethane mixture comprising one or more water-dispersible polyurethanes and one or more organic solvents. In alternative embodiments, the wet-spun fibers can be spun from a polyurethane mixture comprising one or more water-dispersible polyurethanes and an aqueous polyethylene oxide solution. In some embodiments, the wet-spun fibers can be spun from a polyurethane mixture comprising one or more water-dispersible polyurethanes, one or more organic solvents, and an aqueous polyethylene oxide solution.

[0091] In some embodiments, the organic solvent can be miscible with water. In some embodiments, the organic solvent can be an ether-containing solvent, such as tetrahydrofuran (THF) or dimethoxymethane. In some embodiments, the ether-containing solvent can be a polyether. Examples of suitable ether-containing solvents include, but are not limited to, tert-amyl ethyl ether, cyclopentyl methyl ether, di-tert-butyl ether, di(propylene glycol) methyl ether, dibutyl ether, diethyl ether, diisopropyl ether, dimethoxy ethane, dimethoxymethane, 1,4-dioxane, ethyl tert-butyl ether, methoxy ethane, 2-(2-methoxyethoxy)ethanol, methyl tert-butyl ether, 2-methyltetrahydrofuran, morpholine, propylene glycol methyl ether, tetrahydrofurfuryl alcohol, tetrahydropyran, 2,2,5,5-tetramethyltetrahydrofuran, and polyethylene glycol.

[0092] In some embodiments, the organic solvent can be an ester-containing solvent, such as butyl acetate. Examples of other suitable ester-containing solvents include, but are not limited to, ethyl acetate, propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, and ethyl, hexyl acetate.

[0093] In some embodiments, the organic solvent can comprise an ether-containing solvent and an ester-containing solvent.

[0094] Surprisingly, the presence of the organic solvent, the aqueous polyethylene oxide solution, or both facilitates the formation of wet-spun polyurethane fibers made from a mixture comprising a waterborne polyurethane dispersion within a coagulation bath (see, for example. Example 3 and Example 6). Without the organic solvent or aqueous polyethylene oxide solution, wet-spun waterborne polyurethane dispersion mixtures described herein will not form continuous fibers and will instead form non-continuous beads (see, for example, Example 1). Without wishing to be bound by theory, it is believed the organic solvent, the aqueous polyethylene oxide solution, or both facilitate forming continuous fibers by increasing polymer chain entanglement that improves the spinnability. Here again, without wishing to be bound by theory, it is believed that the organic solvent and aqueous polyethylene oxide are capable of increasing polymer chain entanglement without causing precipitation or causing phase separation of the waterborne polyurethane dispersion, which allows for improved spinnability. [0095] By facilitating the formation of wet-spun polyurethane fibers, the organic solvent, the aqueous polyethylene oxide solution, or both can also facilitate the formation of wet- spun polyurethane fibers from waterborne polyurethane dispersion mixtures comprising other components miscible within the polyurethane dispersion mixture. For example, in some embodiments, the wet-spun polyurethane fibers can comprise one or more proteins dissolved within the polyurethane of the fibers. In such embodiments, the wet-spun polyurethane fibers comprise a “protein polyurethane alloy” as described herein.

[0096] The wet-spun polyurethane fibers described herein offer advantages over other polymeric fibers, including other polyurethane fibers made using different methods, such as different wet spinning methods or dry spinning methods. The wet-spun polyurethane fibers described herein can have lengths suitable for creating various fabric materials, including woven, non-woven, and knitted materials. The wet-spun polyurethane fibers described herein can have mechanical/performance properties, aesthetic properties, and/or thermal properties that allow them to be utilized in the creation of materials having properties similar to or superior to natural leather or other common fabric materials. Fiber mechanical/performance properties include, but are not limited to, tenacity (strength), modulus, elongation at break, water resistance, breathability, and the ability to be dyed with reactive dyes and retain color when rubbed (color fastness). Fiber aesthetic properties can include, but are not limited to, dyeability, aging, color, color depth, and color patterns. Fiber thermal properties include, but are not limited to, heat resistance and resistance to stiffening or softening over a significantly wide temperature range, for example 25 °C to 100 °C.

[0097] FIGS. 1 and 2 illustrate a wet-spun polyurethane fiber 100 according to some embodiments. Fiber 100 comprises an exterior surface 102 and a core 106 surrounding a cross-sectional center 104 of fiber 100. The dimensions of fiber 100 can be defined by one or more of the length 110 of fiber 100, the effective diameter 112 of fiber 100, or the aspect ratio of fiber 100, which is defined as the ratio of length 110 to effective diameter 112.

[0098] In some embodiments, the length 110 of fiber 100 can be greater than or equal to about 5 millimeters. In some embodiments, the length 110 of fiber 100 can range from about 5 millimeters to about 1000 meters, including subranges. For example, in some embodiments, length 110 can range from about 5 millimeters to about 500 meters, from about 5 millimeters to about 200 meters, from about 10 millimeters to about 1000 meters, or from about 100 millimeters to about 1000 meters. In some embodiments, length 110 of fiber 100 can be greater than 1000 meters.

[0099] In some embodiments, the effective diameter 112 of fiber 100 can range from about 1 micrometer to about 1 centimeter, including subranges. For example, in some embodiments, the effective diameter 112 of fiber 100 can range from about 1 micrometer to about 5 millimeters, from about 1 micrometer to about 1 millimeter, from about 1 micrometer to about 500 micrometers, from about 1 micrometer to about 100 micrometers, from about 100 micrometers to about 1 centimeter, from about 500 micrometers to about 1 centimeter, from about 1 millimeter to about 1 centimeter, or from about 5 millimeters to about 1 centimeter.

[0100] In some embodiments, fiber 100 can have an aspect ratio of greater than or equal to about 10. In some embodiment, fiber 100 can have an aspect ratio ranging from about 10 to about 1000, including subranges. For example, in some embodiments, the aspect ratio of fiber 100 can range from about 10 to about 750, from about 10 to about 500, from about 10 to about 250, or from about 10 to about 100.

[0101] In some embodiments, fiber 100 can comprise one or more protein polyurethane alloys. In such embodiments, protein polyurethane alloy can define core 106 of fiber 100. In some embodiments, fiber 100 can comprise greater than or equal to 80 wt% protein polyurethane alloy. In some embodiments, fiber 100 can comprise greater than or equal to 85 wt% protein polyurethane alloy. In some embodiments, fiber 100 can comprise greater than or equal to 90 wt% protein polyurethane alloy. In some embodiments, fiber 100 can comprise greater than or equal to 95 wt% protein polyurethane alloy. In some embodiments, fiber 100 can consist essentially of protein polyurethane alloy (i.e., consist of only the alloy with less than about 1 wt % impurities or other components).

[0102] Protein polyurethane alloys for fiber 100 described herein comprise a protein dissolved within a polyurethane, or a plurality of polyurethanes. In particular embodiments, the protein polyurethane alloys described herein can comprise a protein that is miscible with only one of a plurality of phases of the polyurethane, or the plurality of polyurethanes, with which it is blended. For example, in some embodiments, the protein polyurethane alloy can include a protein that is miscible with only the hard phase of the polyurethane, or the plurality of polyurethanes, having both a hard phase and a soft phase. [0103] A protein for use in the protein polyurethane alloys disclosed herein can be a protein containing lysine. In some embodiments, the protein can be a soy protein. In some embodiments, the protein can be soy protein isolate. In some embodiments, the protein can be a collagen. In some embodiments, the protein can be gelatin. In some embodiments, the protein can be bovine serum albumin. In some embodiments, the protein can be pea protein. In some embodiments, the protein can be egg white albumin. In some embodiments, the protein can be casein protein. In some embodiments, the protein can be peanut protein. In some embodiments, the protein can be edestin protein.

In some embodiments, the protein can be whey protein. In some embodiments, the protein can be karanja protein. In some embodiments, the protein can be hemp protein. In some embodiments, the protein can be an enzyme. In some embodiments, the protein can be cellulase.

[0104] Suitable water-dispersible polyurethanes for use in the fibers comprising the protein polyurethane alloy described herein include those that comprise at least two phases including a “soft phase” and a “hard phase.” The soft phase is formed from polyol segments within the polyurethane that separate from the urethane-containing phase due to differences in polarity. The urethane-containing phase is referred to as the hard phase. This phase separation is well known in the art and is the basis of the many of the properties of polyurethanes.

[0105] The soft phase is typically elastomeric at room temperature, and typically has a softening point or glass transition temperature (Tg) below room temperature. The Tg can be measured by Dynamic Mechanical Analysis (DMA) and quantified by either the peak of tan(5) or the onset of the drop in storage modulus. Alternately, Tg can be measured by Differential Scanning Calorimetry (DSC). In some cases, there can be crystallinity in the soft phase, which can be seen as a melting point, typically between 0 °C and about 60 °C.

[0106] The hard phase typically has a Tg or melting point above room temperature, more typically above about 80 °C. The softening of the hard phase can be measured by measuring the onset of the drop in storage modulus (sometimes referred to as stiffness) as measured by DMA.

[0107] The “soft phase” for the polyurethane or the protein polyurethane alloy including the polyurethane comprises the polyol component of the polyurethane. Its function is to be soft and flexible at temperatures above its Tg to lend toughness, elongation, and flexibility to the polyurethane. Typical soft segments can comprise polyether polyols, polyester polyols, polycarbonate polyols, and mixtures thereof. The soft segments typically range in molecular weight from about 250 D to greater than about 5 k.D. The “hard phase” for the polyurethane or the protein polyurethane alloy including the polyurethane comprises the urethane segments of the polymer that are imparted by the isocyanate(s) used to connect the polyols along with short chain diols such as butane diol, propane diol, and the like. Typical isocyanates useful for the present polyurethanes include, but are not limited to, hexamethylene diisocyanate, isophorone diisocyanate, methylene diisocyanate, phenyl diisocyanate, and the like. These molecules are more polar and stiffer than the polyols used to make the soft segment. Therefore, the hard segment is stiffer and has a higher softening point compared to the soft segment. The function of the hard phase is to provide, among other properties, strength, temperature resistance, and abrasion resistance to the polyurethane.

[0108] In some embodiments described herein, the protein can be miscible with only the hard phase, leaving soft phase transitions substantially unaltered. Without wishing to be bound by particular theory, it is believed that when the protein is dissolved in the hard phase, it significantly increases the temperature at which the hard phase begins to soften, thus increasing the temperature resistance of the alloy.

[0109] In a protein polyurethane alloy including one or more miscible proteins and polyurethanes, the one or more proteins can be dissolved within the hard phase of the one or more polyurethanes. The protein polyurethane alloy can include at least one protein miscible with the hard phase of one or more polyurethanes in the alloy. In some embodiments, the protein polyurethane alloy can include a plurality of proteins and/or a plurality of polyurethane hard phases that are miscible with each other. In all of these embodiments, and without wishing to be bound by a particular theory, the protein, or plurality of proteins, is believed to be dissolved in the hard phase of the polyurethane, or plurality of polyurethanes.

[0110] One or more proteins dissolved within the hard phase of one or more polyurethanes can form a homogenous mixture when blended. In some embodiments, the protein polyurethane alloy can include a plurality of proteins dissolved within one or more polyurethanes such that the proteins and the polyurethane(s) form a homogenous mixture when blended and dried. Typically, the protein polyurethane alloy including a homogenous mixture of protein and polyurethane does not include a substantial amount of protein not dissolved in the polyurethane. That said, and in some embodiments, the protein polyurethane alloy can include a fraction of protein dispersed within the polyurethane.

[0111] In some embodiments, the protein polyurethane alloy can be transparent. In some embodiments, a transparent protein polyurethane alloy can indicate that the protein is miscible with the hard phase of the polyurethane in the alloy. As used herein, a “transparent” material means material having an opacity of about 50% or less. Opacity is measured by placing a sample of material over a white background to measure the Y tristimulus value (“Over white Y”) in reflectance with a spectrometer using the D65 10 degree illuminant. The same sample is then placed over a black background and the measurement is repeated, yielding “Over black Y”. Percent opacity is calculated as “Over black Y” divided by “Over white Y” times 100. 100% opacity is defined as lowest transparency and 0% opacity is defined as the highest transparency.

[0112] In some embodiments, the protein polyurethane alloy can be transparent and can have an opacity ranging from 0% to about 50%, including subranges. For example, the transparent protein polyurethane alloy, can have an opacity ranging from 0% to about 40%, 0% to about 30%, 0% to about 20%, 0% to about 10%, or 0% to about 5%. The transparency of the protein polyurethane alloy is evaluated before dyeing or otherwise coloring the protein polyurethane alloy.

[0113] A transparent protein polyurethane alloy can be created by selecting and blending the appropriate combination of one or more proteins and one or more polyurethanes. While not all combinations of protein and polyurethane will result in a transparent protein polyurethane alloy, it is within the skill of the ordinarily skilled artisan to identify whether a given blend results in a transparent protein polyurethane alloy in view of this disclosure. In embodiments directed to a fiber comprising a transparent protein polyurethane alloy described herein, the transparent protein polyurethane alloy can provide unique characteristics for the fiber. For example, compared to a non-transparent fiber, the transparent protein polyurethane alloy can provide unique depth of color when dyed.

[0114] Suitable water-dispersible polyurethanes for protein polyurethane alloys according to embodiments described herein include, but are not limited to, aliphatic polyurethanes, aromatic polyurethanes, bio-based polyurethanes, or acrylic acid modified polyurethanes. Suitable polyurethanes are commercially available from manufacturers including Lubrizol, Hauthaway, Stahl, and the like. In some embodiments, a polyurethane for a protein polyurethane alloy can be a bio-polyurethane. In some embodiments, the polyurethane can be a polyester polyurethane. In some embodiments, the polyurethane can be a polyether polyurethane. In some embodiments, the polyurethane can be a polycarbonate-based polyurethane. In some embodiments, the polyurethane can be an aliphatic polyester polyurethane. In some embodiments, the polyurethane can be an aliphatic polyether polyurethane. In some embodiments, the polyurethane can be an aliphatic polycarbonate polyurethane. In some embodiments, the polyurethane can be an aromatic polyester polyurethane. In some embodiments, the polyurethane can be an aromatic polyether polyurethane. In some embodiments, the polyurethane can be an aromatic polycarbonate polyurethane.

[0115] In some embodiments, the polyurethane can have a soft segment selected from the group consisting of: polyether polyols, polyester polyols, polycarbonate polyols, and mixtures thereof. In some embodiments, the polyurethane can have a hard segment comprising diisocyanates and optionally short chain diols. Suitable diisocyanates can be selected from the group consisting of: aliphatic diisocyanates such as hexamethylene diisocyanate, isophorone diisocyanate; aromatic diisocyanates such as 4,4’ diphenyl methylene diisocyanate, toluene diisocyanate, phenyl diisocyanate, and mixtures thereof. Suitable short chain diols include ethylene glycol, propane diol, butane diol, 2,2 methyl 1,3 propane diol, pentane diol, hexane diol and mixtures thereof. In some embodiments crosslinkers such as multifunctional alcohols, for example, trimethylol propane triol, or diamines such as ethylene diamine or 4,4’diamino, diphenyl diamine.

[0116] Exemplary commercial polyurethanes, include but are not limited to L3360 and Hauthane HD-2001 available from C.L. Hauthaway & Sons Corporation, SANCURE™ polyurethanes available from Lubrizol Corporation, BONDTHANE™ polyurethanes, for example UD-108, UD-250, and UD-303 available from Bond Polymers International, EPOTAL® ECO 3702 and EPOTAL® Pl 00 ECO from BASF, Permutex Evo EX-RC- 2214 (RC-2214) from Stahl, and HYDRAN® WLF-286BP from DIC Corporation. L3360 is a aliphatic polyester polyurethane polymer aqueous dispersion having a 35% solids content, a viscosity of 50 to 500 cps (centipoise), and a density of about 8.5 Ib/gal (pounds per gallon). HD-2001 is an aliphatic polyester polyurethane polymer aqueous dispersion having a 40% solids content, a viscosity of 50 to 500 cps, and a density of about 8.9 Ib/gal. BONDTHANE™ UD-108 is an aliphatic polyether polyurethane polymer aqueous dispersion having a 33% solids content, a viscosity of 300 cps, and a density of 8.7 Ib/gal. BONDTHANE™ UD-250 is an aliphatic polyester polyurethane polymer aqueous dispersion having a 35% solids content, a viscosity of 200 cps, and a density of 8.8 Ib/gal. BONDTHANE™ UD-303 is an aliphatic polyether polyurethane polymer aqueous dispersion having a 35% solids content, a viscosity of less than 500 cps, and a density of 8.7 Ib/gal. EPOTAL® P100 ECO is a polyester polyurethane elastomer aqueous dispersion having approximately 40% solids and a viscosity of about 40 mPas. RC-2214 is an aliphatic polyether polyurethane polymer aqueous dispersion having a 58- 60% solids content, a viscosity of 4,000 to 15,000 cps, and a density of about 8.9 Ib/gal. HYDRAN® WLF-286BP is a bio-based waterborne aliphatic polycarbonate type polyurethane anionic aqueous dispersion having a 32-36% solids content, and a viscosity of 5 to 1,000 cps.

[0117] Exemplary bio-based polyurethanes include, but are not limited to, L3360 available from C.L. Hauthaway & Sons Corporation, IMPRANIL® Eco DLS, IMPRANIL® Eco DE 519, IMPRANIL® Eco DLP-R, and IMPRAPERM® DL 5249 available from Covestro. IMPRANIL® Eco DLS is an anionic, aliphatic polyester polyurethane polymer aqueous dispersion having approximately 50% solids content, a viscosity of less than 1,200 MPa s, and a density of about 1.1 g/cc. IMPRANIL® Eco DL 519 is an anionic, aliphatic polyester polyurethane polymer aqueous dispersion.

IMPRANIL® Eco DLP-R is an anionic, aliphatic polyester polyurethane polymer aqueous dispersion. IMPRAPERM® DL 5249 is an anionic aliphatic polyester-polyurethane polymer aqueous dispersion.

[0118] In some embodiments, the polyurethane can include reactive groups that can be cross-linked with a protein. Exemplary reactive groups include, but are not limited to, a sulfonate, an aldehyde, a carboxylic acid or ester, a blocked isocyanate, or the like, and combinations thereof. In such embodiments, the polyurethane can be crosslinked to the protein in the protein polyurethane alloy through the reaction of a reactive group on the protein with the reactive group present in the polyurethane.

[0119] Suitable proteins for protein polyurethane alloys according to embodiments described herein include, but are not limited to, collagen, gelatin, bovine serum albumin (BSA), soy proteins, pea protein, egg white albumin, casein, peanut protein, edestin protein, whey protein, karanja protein, cellulase, and hemp. Suitable collagens include, but are not limited to, recombinant collagen (r-Collagen), a recombinant collagen fragment, and extracted collagens. Suitable soy proteins include, but are not limited to, soy protein isolate (SPI), soymeal protein, and soy protein derivatives. In some embodiments, the soy protein isolate can be partially hydrolyzed soy protein isolate. Suitable pea proteins include, but are not limited to, pea protein isolate, and pea protein derivatives. In some embodiments, the pea protein isolate can be partially hydrolyzed pea protein isolate.

[0120] Table 1 below lists some exemplary proteins. The gelatin is gelatin from porcine skin, Type A (Sigma Aldrich G2500). The collagen is extracted bovine collagen purchased from Wuxi BIOT Biology-technology Company. The bovine serum albumin Sigma Aldrich 5470 bovine serum albumin. The r-Collagen is recombinant collagen from Modem Meadow. The soy protein isolate is soy protein isolate purchased from MP Medicals (IC90545625). The pea protein is pea protein powder purchased from Bobs Red Mills (MTX5232). The egg white albumin protein is albumin from chicken egg white (Sigma Aldrich A5253). The casein protein is casein from bovine milk (Sigma Aldrich C7078). The peanut protein is peanut protein powder purchased from Tru-Nut. The whey protein is whey from bovine milk (Sigma Aldrich W1500). Other suitable soy protein isolates include, but are not limited to, soy protein isolate purchased from AMD (Clarisoy 100, 110, 150, 170, 180), or DuPont (SUPRO® XT 55, SUPRO® XT 221D, SUPRO® XT 221D-IP, and SOB IND® Balance). Other suitable pea protein powders include, but are not limited to, pea protein powder purchased from Puris (870 and 870H).

[0121] Karanja protein is a protein found in Karanja seeds harvested from Pongamia pinnata trees (also known as Pongamia glabra trees). See Rahman, M., and Netravali, “Green Resin from Forestry Waste Residue ‘Karanja (Pongamia pinnata) Seed Cake’ for Biobased Composite Structures,” ACS Sustainable Chem. Eng., 2: 2318-2328 (2014); see also Mandal et al., “Nutritional Evaluation of Proteins from three Non-traditional Seeds with or without Amino Acids Supplementation in Albino Rats,” Proc. Indian natn. Sci. Acad., B50, No. 1, 48-56 (1984). The protein can be extracted from Karanja seeds using a solvent extraction process. Id In some embodiments, the karanja protein can be karanja protein isolate. In such embodiments, karanja protein isolate can be obtained by alkaline extraction and acid precipitation of defatted karanja seed cake. See Rahman, M., and Netravali, “Green Resin from Forestry Waste Residue ‘Karanja (Pongamia pinnata) Seed Cake’ for Biobased Composite Structures,” ACS Sustainable Chem. Eng., 2: 2318-2328 (2014). [0122] Suitable cellulase proteins are listed below in Table 1. The “Cellulase-RG” protein is Native Trichoderma sp. Cellulase available from CREATIVE ENZYMES®. The “Cellulase-IG” protein is laboratory grade cellulase available from Carolina Biological Supply Company.

[0123] The 50 KDa recombinant collagen fragment (50 KDa r-Collagen fragment) in Table 1 is a collagen fragment comprising the amino acid sequence listed as SEQ ID NO: I.

[0124] The “dissolution method” listed in Table 1 is an exemplary aqueous solvent in which the protein can be dissolved in a solution that is miscible with the hard phase of the polyurethane as described herein. Proteins that can be at least partly dissolved in an aqueous solution are suitable for forming protein polyurethane alloys with waterborne polyurethane dispersions.

Table 1

[0125] In some embodiments, the protein can have one or more of the following properties: (i) a molecular weight within a range described herein (ii) an isoelectric point within a range described below, (iii) an amino acid composition measured in grams of lysine per 100 grams of protein in a range described below, and (iv) protein thermostability up to 200 °C.

Protein Molecular Weight

[0126] In some embodiments, the protein suitable for blending with the polyurethane can have a molecular weight ranging from about 1 KDa to about 700 KDa, including subranges. For example, the protein can have a molecular weight ranging from about 1 KDa to about 700 KDa, about 10 KDa to about 700 KDa, about 20 KDa to about 700 KDa, about 50 KDa to about 700 KDa, about 100 KDa to about 700 KDa, about 200 KDa to about 700 KDa, about 300 KDa to about 700 KDa, about 400 KDa to about 700 KDa, about 500 KDa to about 700 KDa, about 600 KDa to about 700 KDa, about 1 KDa to about 600 KDa, about 1 KDa to about 500 KDa, about 1 KDa to about 400 KDa, about 1 KDa to about 300 KDa, about 1 KDA to about 200 KDa, about 1 KDa to about 100 KDa, about 1 KDa to about 50 KDa, about 1 KDa to about 20 KDa, or about 1 KDa to about 10 KDa, or within a range having any two of these values as endpoints, inclusive of the endpoints. Protein Isoelectric Point

[0127] In some embodiments, the protein suitable for blending with the polyurethane can have an isoelectric point ranging from about 4 to about 10, including subranges. For example, the protein can have an isoelectric point ranging from about 4 to about 10, about 4.5 to about 9.5, about 5 to about 9, about 5.5 to about 8.5, about 6 to about 8, about 6.5 to about 7.5, or about 6.5 to about 7, or within a range having any two of these values as endpoints, inclusive of the endpoints. In some embodiments, the protein can have an isoelectric point ranging from about 4 to about 5.

Protein Amino Acid Composition

[0128] In some embodiments, the protein suitable for blending with the polyurethane can have an amino acid composition measured in grams of lysine per 100 grams of protein (as referred to as a “lysine weight percent”) ranging from about 0.5 wt% to about 100 wt%, including subranges. For example, the protein can have a lysine weight percent ranging from about 0.5 wt% to about 100 wt%, about 1 wt% to about 100 wt%, about 5 wt% to about 100 wt%, about 10 wt% to about 100 wt%, about 20 wt% to about 100 wt%, about 30 wt% to about 100 wt%, about 40 wt% to about 100 wt%, about 50 wt% to about 100 wt%, about 60 wt% to about 100 wt%, about 70 wt% to about 100 wt%, about 80 wt% to about 100 wt%, or about 90 wt% to about 100 wt%, or within a range having any two of these values as endpoints, inclusive of the endpoints. In some embodiments, the protein can be a polylysine.

[0129] In some embodiments, the protein suitable for blending with the polyurethane can have a lysine weight percent ranging from about 0.5 wt% to about 20 wt%, including subranges. For example, the protein can have a lysine weight percent ranging from about 0.5 wt% to about 20 about 1 wt% to about 19 wt%, about 2 wt% to about 18 wt%, about 3 wt% to about 17 wt%, about 4 wt% to about 16 wt%, about 5 wt% to about 15 wt%, about 6 wt% to about 14 wt%, about 7 wt% to about 13 wt%, about 8 wt% to about 12 wt%, about 9 wt% to about 11 wt%, or about 9 wt% to about 10 wt%, or within a range having any two of these values as endpoints, inclusive of the endpoints. In some embodiments, the protein can have a lysine weight percent ranging from about 1 wt% to about 20 wt%. In some embodiments, the protein can have a lysine weight percent ranging from about 5 wt% to about 20 wt%. In some embodiments, the protein can have a lysine weight percent ranging from about 1 wt% to about 12 wt%. In some embodiments, the protein can have a lysine weight percent ranging from about 5 wt% to about 12 wt%. In some embodiments, the protein can have a lysine weight percent ranging from about 1 wt% to about 15 wt%. In some embodiments, the protein can have a lysine weight percent ranging from about 5 wt% to about 15 wt%.

[0130] In some embodiments, the protein suitable for blending with the polyurethane can be thermo-stable. In some embodiments, the protein can be non-thermo-stable. As described herein, protein thermo-stability is determined by a differential scanning calorimetry (DSC), where a pre-dried protein powder (with moisture less than 3%) is scanned from 0 °C to 200 °C. In the protein’s DSC curves, an endothermic peak larger than 10 mW/mg is determined to be a “denaturation peak”, and the temperature corresponding to the endothermic “denaturation peak” is defined as the “denaturation temperature” of the protein. A protein that is “ther o- stable” means that the protein has denaturation temperature of 200 °C or more. For purposes of the present disclosure, a protein with a denaturation temperature below 200 °C is considered “non-thermo-stable.”

Protein Dissolution

[0131] In some embodiments, before blending with one or more polyurethanes, one or more proteins can be dissolved in an aqueous solution to form an aqueous protein mixture. In some embodiments, dissolving the protein in an aqueous solution before blending the protein with one or more polyurethanes can facilitate miscibility of the protein with the hard phase of the one or more polyurethanes. For example, dissolving the protein in an aqueous solution before blending the protein with one or more polyurethanes can facilitate miscibility of the protein with the hard phase of the polyurethane(s). Not all proteins are naturally miscible with any phase of a polyurethane.

[0132] Suitable aqueous solutions include, but are not limited to, water, an aqueous alkali solution, an aqueous acid solution, an aqueous solution including an organic solvent, a urea solution, and mixtures thereof. In some embodiments, the aqueous alkali solution can be a basic solution such as a sodium hydroxide, ammonia or ammonium hydroxide solution. In some embodiments, examples of an acidic aqueous solution can be an acetic acid or hydrochloric acid (HC1) solutions. Suitable organic solvents include, but are not limited to, ethanol, isopropanol, acetone, ethyl acetate, isopropyl acetate, glycerol, and the like. In some embodiments, the protein concentration in the aqueous protein mixture can range from about 10 g/L to about 300 g/L, including subranges. [0133] In some embodiments, the amount of protein in the protein polyurethane alloy can range from about 5 wt% to about 50 wt% of protein, including subranges. For example, in some embodiments, the amount of protein in the polyurethane alloy can range from about 5 wt% to about 50 wt%, about 10 wt% to about 50 wt%, about 15 wt% to about 50 wt%, about 20 wt% to about 50 wt%, about 25 wt% to about 50 wt%, about 30 wt% to about 50 wt%, about 35 wt% to about 50 wt%, about 40 wt% to about 50 wt%, about 45 wt% to about 50 wt%, about 5 wt% to about 45 wt%, about 5 wt% to about 40 wt%, about 5 wt% to about 35 wt%, about 5 wt% to about 30 wt%, about 5 wt% to about 25 wt%, about 5 wt% to about 20, about 5 wt% to about 15 wt%, or about 5 wt% to about 10 wt% or within a range having any two of these values as endpoints, inclusive of the endpoints. In some embodiments, the amount of protein in the protein polyurethane alloy can range from about 5 wt% to about 20 wt%. In some embodiments, the amount of protein in the protein polyurethane alloy can range from about 20 wt% to about 35 wt%.

[0134] In some embodiments, the amount of polyurethane in the protein polyurethane alloy can range from about 50 wt% to about 95 wt%, including subranges. For example, in some embodiments, the amount of polyurethane in the protein polyurethane alloy can range from about 50 wt% to about 95 wt%, about 55 wt% to about 95 wt%, about 60 wt% to about 95 wt%, about 65 wt% to about 95 wt%, about 70 wt% to about 95 wt%, about 75 wt% to about 95 wt%, about 80 wt% to about 95 wt%, about 85 wt% to about 95 wt%, about 90 wt% to about 95 wt%, about 50 wt% to about 90 wt%, about 50 wt% to about 85 wt%, about 50 wt% to about 80 wt%, about 50 wt% to about 75 wt%, about 50 wt% to about 70 wt%, about 50 wt% to about 65 wt%, about 50 wt% to about 60 wt%, or about 50 wt% to about 55 wt%, or within a range having any two of these values as endpoints, inclusive of the endpoints. In some embodiments, the amount of polyurethane in the protein polyurethane alloy can range from about 80 wt% to about 95 wt%. In some embodiments, the amount of polyurethane in the protein polyurethane alloy can range from about 65 wt% to about 80 wt%.

[0135] Any of the above-listed ranges for the weight percentages of protein and polyurethane in the protein polyurethane alloy can be combined. For example, in some embodiments, the weight percentages of protein and polyurethane in the protein polyurethane alloy can be any of the following. The amount of protein in the polyurethane alloy can range from about 5 wt% to about 50 wt% and the amount of polyurethane in the protein polyurethane alloy can range from about 50 wt% to about 95 wt%. The amount of protein in the polyurethane alloy can range from about 15 wt% to about 50 wt% and the amount of polyurethane in the protein polyurethane alloy can range from about 50 wt% to about 85 wt%. The amount of protein in the polyurethane alloy can range from about 20 wt% to about 50 wt% and the amount of polyurethane in the protein polyurethane alloy can range from about 50 wt% to about 80 wt%. The amount of protein in the polyurethane alloy can range from about 25 wt% to about 50 wt% and the amount of polyurethane in the protein polyurethane alloy can range from about 50 wt% to about 75 wt%. The amount of protein in the polyurethane alloy can range from about 30 wt% to about 50 wt% and the amount of polyurethane in the protein polyurethane alloy can range from about 50 wt% to about 70 wt%. The amount of protein in the polyurethane alloy can range from about 10 wt% to about 40 wt% and the amount of polyurethane in the protein polyurethane alloy can range from about 60 wt% to about 90 wt%. The amount of protein in the polyurethane alloy can range from about 15 wt% to about 40 wt% and the amount of polyurethane in the protein polyurethane alloy can range from about 60 wt% to about 85 wt%. The amount of protein in the polyurethane alloy can range from about 20 wt% to about 40 wt% and the amount of polyurethane in the protein polyurethane alloy can range from about 60 wt% to about 80 wt%. The amount of protein in the polyurethane alloy can range from about 20 wt% to about 35 wt% and the amount of polyurethane in the protein polyurethane alloy can range from about 65 wt% to about 80 wt%. In some embodiments, the above-listed weight percent values and ranges can be based on the total weight of the protein polyurethane alloy. In some embodiments, the above-listed weight percent values and ranges can be based on the total weight of only protein and polyurethane in a protein polyurethane alloy. Unless otherwise specified, a weight percent value or range for the polyurethane and the protein is based on the total weight of only protein and polyurethane in a protein polyurethane alloy.

[0136] In some embodiments, the sum of the amount of protein plus the amount of polyurethane in the protein polyurethane alloy can be about 80 wt% or more. For example, in some embodiments, the sum of the amount of protein plus the amount of polyurethane in the protein polyurethane alloy can range from about 80 wt% to 100 wt%, about 82 wt% to 100 wt%, about 84 wt% to 100 wt%, about 86 wt% to 100 wt%, about 88 wt% to 100 wt%, about 90 wt% to 100 wt%, about 92 wt% to 100 wt%, about 94 wt% to 100 wt%, about 96 wt% to 100 wt%, or about 98 wt% to 100 wt%. [0137] In some embodiments, the protein polyurethane alloy can be a protein polyurethane alloy as described in U.S. Pub. No. 2021/0355326, which is hereby incorporated by reference in its entirety.

[0138] Protein polyurethane alloys described herein can be free of or substantially free of protein in the form of particles dispersed in a polyurethane. For example, in some embodiments, the protein polyurethane alloys can be free of or substantially free of protein particles having an average diameter of greater than 1 micron (pm).

[0139] In some embodiments, the protein polyurethane alloys can be free of or substantially free of soy protein particles having an average diameter of greater than 1 micron (pm). In some embodiments, the protein polyurethane alloys can be free of or substantially free of collagen particles having an average diameter of greater than 1 micron (pm). In some embodiments, the protein polyurethane alloys can be free of or substantially free of gelatin particles having an average diameter of greater than 1 micron (pm). In some embodiments, the protein polyurethane alloys can be free of or substantially free of bovine serum albumin particles having an average diameter of greater than 1 micron (pm). In some embodiments, the protein polyurethane alloys can be free of or substantially free of pea protein particles having an average diameter of greater than 1 micron (pm). In some embodiments, the protein polyurethane alloys can be free of or substantially free of egg white albumin particles having an average diameter of greater than 1 micron (pm). In some embodiments, the protein polyurethane alloys can be free of or substantially free of casein protein particles having an average diameter of greater than 1 micron (pm). In some embodiments, the protein polyurethane alloys can be free of or substantially free of peanut protein particles having an average diameter of greater than 1 micron (pm). In some embodiments, the protein polyurethane alloys can be free of or substantially free of edestin protein particl es having an average diameter of greater than 1 micron (pm). In some embodiments, the protein polyurethane alloys can be free of or substantially free of whey protein particles having an average diameter of greater than 1 micron (pm). In some embodiments, the protein polyurethane alloys can be free of or substantially free of karanja protein particles having an average diameter of greater than 1 micron (pm). In some embodiments, the protein polyurethane alloys can be free of, or substantially free of, cellulase particles having an average diameter of greater than 1 micron (pm). In some embodiments, the protein polyurethane alloys can be free of, or substantially free of, recombinant collagen fragment particles having an average diameter of greater than 1 micron (pm). In some embodiments, the protein polyurethane alloys can be free of, or substantially free of, hemp protein particles having an average diameter of greater than 1 micron (pm).

[0140] In some embodiments, the proteins for use in fibers comprising a protein polyurethane alloy can be succinylated proteins. A succinyl ated protein is a protein modified with the addition of a succinyl group to a side chain of an amino acid in the protein. Most commonly, the succinyl group is added to lysine side chains. The method of adding a succinyl group to a side chain of an amino acid in a protein is commonly referred to as protein succinylation. Addition of succinyl groups on a protein can alter the protein’s functional and structural properties. In some cases, the addition of a relatively large modification like a succinyl moiety can be expected to alter the tertiary structure of the protein. Further, with the addition of a succinyl moiety, a lysine side chain can be altered from a primary amine to an acid, making it more hydrophilic, and can change its charge from positive to negative in physiological pH. Succinylation can be accomplished using techniques and chemistry well known the art.

[0141] A succinylated protein for use in the polyurethane alloys disclosed herein can be a protein containing lysine. In some embodiments, the succinylated protein can be a succinylated soy protein. In some embodiments, the succinylated protein can be a succinylated soy protein isolate. In some embodiments, the succinylated protein can be a succinylated collagen. In some embodiments, the succinylated protein can be a succinylated gelatin. In some embodiments, the succinylated protein can be succinylated bovine serum albumin. In some embodiments, the succinylated protein can be a succinylated pea protein. In some embodiments, the succinylated protein can be succinylated egg white albumin. In some embodiments, the succinylated protein can be a succinylated casein protein. In some embodiments, the succinylated protein can be a succinylated peanut protein. In some embodiments, the succinylated protein can be a succinylated edestin protein. In some embodiments, the succinylated protein can be a succinylated whey protein. In some embodiments, the succinylated protein can be a succinylated karanja protein. In some embodiments, the succinylated protein can be a succinylated cellulase. In some embodiments, the succinylated protein can be a succinylated hemp protein.

[0142] In some embodiments, the succinylated protein can have a solubility in water, measured as described below, of about 50% to about 100%, including subranges. For example, in some embodiments, the succinylated protein can have a solubility in water of about 50% to about 100%, about 51% to about 100%, about 52% to about 100%, about 53% to about 100%, about 54% to about 100%, about 55% to about 100%, about 56% to about 100%, about 57% to about 100%, about 58% to about 100%, about 59% to about 100%, about 60% to about 100%, about 61% to about 100%, about 62% to about 100%, about 63% to about 100%, about 64% to about 100%, about 65% to about 100%, about 66% to about 100%, about 67% to about 100%, about 68% to about 100%, about 69% to about 100%, about 70% to about 100%, about 71% to about 100%, about 72% to about 100%, about 73% to about 100%, about 74% to about 100%, about 75% to about 100%, about 76% to about 100%, about 77% to about 100%, about 78% to about 100%, about 79% to about 100%, about 80% to about 100%, about 81% to about 100%, about 82% to about 100%, about 83% to about 100%, about 84% to about 100%, about 85% to about 100%, about 86% to about 100%, about 87% to about 100%, about 88% to about 100%, about 89% to about 100%, about 90% to about 100%, about 91% to about 100%, about 92% to about 100%, about 93% to about 100%, about 94% to about 100%, or about 95% to about 100%, or within a range having any two of these values as endpoints, inclusive of the endpoints.

[0143] In some embodiments, the succinylated protein can have a solubility in water of about 60% to about 90%, 61% to about 90%, about 62% to about 90%, about 63% to about 90%, about 64% to about 90%, about 65% to about 90%, about 66% to about 90%, about 67% to about 90%, about 68% to about 90%, about 69% to about 90%, about 70% to about 90%, about 71% to about 90%, about 72% to about 90%, about 73% to about 90%, about 74% to about 90%, about 75% to about 90%, about 76% to about 90%, about 77% to about 90%, about 78% to about 90%, about 79% to about 90%, about 80% to about 90%, about 81% to about 90%, about 82% to about 90%, about 83% to about 90%, about 84% to about 90%, or about 85% to about 90%. In still further embodiments, the succinylated protein can have a solubility in water of about 50%, about 51%, about 52%, about 53%, about 54%, about 55%, about 56%, about 57%, about 58%, about 59%, about 60%, about 61%, about 62%, about 63%, about 64%, about 65%, about 66%, about 67%, about 68%, about 69%, about 70%, about 71%, about 72%, about 73%, about 74%, about 75%, about 76%, about 77%, about 78%, about 79%, about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, about 99%, or about 100%.

[0144] Unless otherwise specified, the solubility of a protein in water is measured according to the following method. The succinylated protein is suspended to a 5% (w/v) aqueous solution with DI water and the total solids are measured with a moisture analyzer. Then 35 mL of the 5% solution is centrifuged in a 50 mL tube for 10 minutes at 15,000 x g (times gravity). After centrifugation, the supernatant is decanted and the volume and total solids of the supernatant (soluble fraction) is measured. The solubility is then calculated as follows: solubility ^:=: (total solids of the supernatant * volume of the supernatant) / (Total solids of the 5% starting solution * volume of the 5% starting solution).

[0145] In some embodiments, the succinylated protein can have an average lysine modification, measured as specified below, of about 20% to about 100%, including subranges. For example, in some embodiments, the succinylated protein can have an average lysine modification of about 20% to about 100%, about 22% to about 100%, about 24% to about 100%, about 25% to about 100%, about 26% to about 100%, about 28% to about 100%, about 30% to about 100%, about 32% to about 100%, about 34% to about 100%, about 35% to about 100%, about 36% to about 100%, about 38% to about 100%, about 40% to about 100%, about 42% to about 100%, about 44% to about 100%, about 45% to about 100%, about 46% to about 100%, about 48% to about 100%, about 50 % to about 100%, about 52% to about 100%, about 54% to about 100%, about 55% to about 100%, about 56% to about 100%, about 58% to about 100%, about 60% to about 100%, about 62% to about 100%, about 64% to about 100%, about 65% to about 100%, about 66% to about 100%, about 68% to about 100%, about 70% to about 100%, about 72% to about 100%, about 74% to about 100%, about 75% to about 100%, about 76% to about 100%, about 78% to about 100%, about 80% to about 100%, about 82% to about 100%, about 84% to about 100%, about 85% to about 100%, about 86% to about 100%, about 88% to about 100%, about 90% to about 100%, about 92% to about 100%, about 94% to about 100%, or about 95% to about 100%, or within a range having any two of these values as endpoints, inclusive of the endpoints.

[0146] In some embodiments, the succinylated protein can have an average lysine modification of about 60% to about 90%, about 62% to about 90%, about 64% to about 90%, about 65% to about 90%, about 66% to about 90%, about 68% to about 90%, about 70% to about 90%, about 72% to about 90%, about 74% to about 90%, about 75% to about 90%, about 76% to about 90%, about 78% to about 90%, about 80% to about 90%, about 82% to about 90%, about 84% to about 90%, or about 85% to about 90%.

[0147] In some embodiments, the succinylated protein can have an average lysine modification of about 60% to about 80%, about 62% to about 80%, about 64% to about 80%, about 65% to about 80%, about 66% to about 80%, about 68% to about 80%, about 70% to about 80%, about 72% to about 80%, about 74% to about 80%, or about 75% to about 80%.

[0148] In still further embodiments, the succinylated protein can have an average lysine modification of about 20%, about 21%, about 22%, about 23%, about 24%, about 25%, about 26%, about 27%, about 28%, about 29%, about 30%, about 31%, about 32%, about 33%, about 34%, about 35%, about 36%, about 37%, about 38%, about 39%, about 40%, about 41%, about 42%, about 43%, about 44%, about 45%, about 46%, about 47%, about 48%, about 49%, about 50%, about 51%, about 52%, about 53%, about 54%, about 55%, about 56%, about 57%, about 58%, about 59%, about 60%, about 61%, about 62%, about 63%, about 64%, about 65%, about 66%, about 67%, about 68%, about 69%, about 70%, about 71%, about 72%, about 73%, about 74%, about 75%, about 76%, about 77%, about 78%, about 79%, about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, about 99%, or about 100%.

[0149] Unless otherwise specified, the average lysine modification for a succinylated protein disclosed herein is measured using the following lysine modification assay. A protein sample is digested using trypsin and loaded onto a liquid chromatography-mass spectrometer (LCZMS). After running the sample on the LC/MS, the sample is mapped by matching the digested peptides against the reference protein sequence for Beta- conglycinin alpha’ subunit (Gene CG-1; Organism: Glycine max (soybean) (Glycine hispida), which contains the possibility for both modified and unmodified lysine residues. Following peptide mapping, peak areas of matched peptides were used to calculate the proportion of modified to unmodified lysine at each lysine residue in the protein sequence and then the average % lysine modification was calculated based on all detected lysines. The following calculations are used to calculate the average % lysine modification. For each detected lysine, the lysine modification % was calculated as equal to the (SUM succinylated lysine / (SUM succinylated lysine + SUM non-succinylated lysine). The overall average % lysine modification is then calculated by averaging the individual lysine modification % of all the detected lysines.

[0150] Protein polyurethane alloy mixtures described herein can be formed by blending one or more proteins with one or more waterborne polyurethane dispersions in a liquid state. In some embodiments, the protein polyurethane alloy mixtures described herein can be formed by blending one or more proteins dissolved or dispersed in an aqueous solution with one or more waterborne polyurethane dispersions in a liquid state. In some embodiments, the waterborne polyurethane dispersion can be ionic, anionic, or cationic. In some embodiments, the waterborne polyurethane dispersion can be nonionic.

[0151] In some embodiments, fiber 100 comprising protein polyurethane alloy defining core 106 of fiber 100 can have a modulus of greater than or equal to about 0.1 cN/tex (centinewtons per tex). In some embodiments, fiber 100 comprising protein polyurethane alloy defining core 106 of fiber 100 can have a modulus ranging from about 0.1 cN/tex to about 10 cN/tex, including subranges. For example, in some embodiments, the modulus can range from about 0.1 cN/'tex to about 5 cN/tex, from about 0. 1 cN/tex to about 2 cN/tex, from about 2 cN/tex to about 10 cN/tex, or from about 5 cN/'tex to about 10 cN/tex.

[0152] In some embodiments, fiber 100 comprising protein polyurethane alloy defining core 106 of fiber 100 can have a Young’s modulus of greater than or equal to about 0.1 cN/tex (centinewtons per tex). In some embodiments, fiber 100 comprising protein polyurethane alloy defining core 106 of fiber 100 can have a Young’s modulus ranging from about 0.1 cN/tex to about 10 cN/tex, including subranges. For example, in some embodiments, the Young’s modulus can range from about 0. 1 cN/'tex to about 5 cN/tex, from about 0.1 cN/tex to about 2 cN/tex, from about 2 cN/tex to about 10 cN/tex, or from about 5 cN/tex to about 10 cN/tex.

[0153] In some embodiments, fiber 100 comprising protein polyurethane alloy defining core 106 of fiber 100 can have a maximum elongation at break (“maximum elongation”) of greater than or equal to about 100%. In some embodiments, the maximum elongation can range from about 100% to about 1000%, including subranges. For example, in some embodiments, the maximum elongation can range from about 100% to about 750%, from about 100% to about 500%, from about 250% to about 1000%, or from about 500% to about 1000%. [0154] In some embodiments, fiber 100 comprising protein polyurethane alloy defining core 106 of fiber 100 can have a tenacity of greater than or equal to about 1 cN/tex. In some embodiments, the tenacity can range from about 1 cN/tex to about 20 cN/tex, including subranges. For example, in some embodiments, the tenacity can range from about 1 cN/tex to about 10 cN/tex, from about 1 cN/tex to about 5 cN/tex, from about 2 cN/tex to about 20 cN/tex, or from about 5 cN/tex to about 20 cN/tex.

[0155] Unless specified otherwise, the modulus, the Young’s modulus the maximum elongation, and the tenacity of a fiber is the modulus, Young’s modulus, maximum elongation, and tenacity of a monofilament measured according to the following test. First, a fiber is conditioned overnight in a conditioning chamber (23 °C ± 1 °C, 50% ± 5% Relative Humidity). After conditioning, the fiber is cut into a 40 ram length section and a piece of tape is attached to each end of the fiber. The fiber is then tested using a tensile property testing machine (INSTRON® 5965 testing machine or similar) fitted with 500 N load cell and 1 kN grips. The fiber is pulled to break at 100 mm/min (millimeters per minute), and the tenacity and maximum elongation are recorded. The modulus, the Young’s modulus, the maximum elongation, and the tenacity of a fiber is reported as the average of at least three 40 mm length sections of fiber made using the same polyurethane mixture and wet spinning process. The “modulus” of a fiber is the tenacity of the fiber measured at 100% elongation during the test. The Young’s modulus of a fiber is calculated on the initial linear portion of the tensile curve obtained using the tensile property testing machine using least-squares fit on test data. The Young’s modulus is the steepest slope of the least squares fit.

[0156] In some embodiments, fiber 100 comprising protein polyurethane alloy defining core 106 of fiber 100 can comprise one or more coloring agents. In some embodiments, the coloring agent can be a colored dye, for example a fiber reactive dye, a direct dye, an acid dye, or a natural dye. Exemplary dyes include, but are not limited to, azo structure acid dyes, metal complex structure acid dyes, anthraquinone structure acid dyes, and azo/diazo direct dyes. In some embodiments, the coloring agent can be pigment, for example a lake pigment.

[0157] In some embodiments, fiber 100 comprising protein polyurethane alloy defining core 106 of fiber 100 can comprise a colored dye and a dye penetration 120 of greater than or equal to about 5% of an effective radius of fiber 100. In some embodiments, fiber 100 comprising protein polyurethane alloy defining core 106 of fiber 100 can comprise a colored dye and a dye penetration 120 greater than or equal to about 25% of an effective radius of fiber 100. In some embodiments, fiber 100 comprising protein polyurethane alloy defining core 106 of fiber 100 can comprise a colored dye and a dye penetration 120 greater than or equal to about 50% of an effective radius of fiber 100. In some embodiments, fiber 100 comprising protein polyurethane alloy defining core 106 of fiber 100 can comprise a colored dye and a dye penetration 120 of greater than or equal to about 90% of an effective radius of fiber 100.

[0158] Fiber 100 comprising protein polyurethane alloy defining core 106 of fiber 100 can be made by extruding a blended mixture into the fiber 100. In some embodiments, the blended mixture can comprise a protein dissolved within a polyurethane, and an organic solvent. In alternative embodiments, the blended mixture can comprise a protein dissolved within a polyurethane, and an aqueous polyethylene oxide solution. In some embodiments, the blended mixture can comprise a protein dissolved within a polyurethane, an organic solvent, and an aqueous polyethylene oxide solution. In some embodiments, extruding the blended mixture into the fiber 100 can comprise wet spinning the blended mixture. After wet spinning in a coagulation bath, fiber 100 can be removed from the coagulation bath and dried. For example, in some embodiments, fiber 100 can be dried in an oven at a temperature of about 70 °C for 12 to 24 hours. In some embodiments, the coagulation bath for wet spinning fiber 100 can comprise acetic acid and water.

[0159] In some embodiments, the protein can be blended with a water-dispersible polyurethane in an aqueous solution to form the blended mixture comprising the protein dissolved within the polyurethane. Before or after the protein is blended with the water- dispersible polyurethane, the organic solvent or the aqueous polyethylene oxide solution can be added to the blended mixture. In some embodiments, the organic solvent can be an ether-containing solvent, such as tetrahydrofuran (THF) or dimethoxymethane. In some embodiments, the ether-containing solvent can comprise a poly ether. Examples of suitable ether-containing solvents include, but are not limited to, tert-amyl ethyl ether, cyclopentyl methyl ether, di-tert-butyl ether, di(propylene glycol) methyl ether, dibutyl ether, diethyl ether, diisopropyl ether, dim ethoxy ethane, dimethoxymethane, 1,4-dioxane, ethyl tert-butyl ether, methoxyethane, 2-(2-methoxyethoxy)ethanol, methyl tert-butyl ether, 2-methyltetrahydrofuran, morpholine, propylene glycol methyl ether, tetrahydrofurfuryl alcohol, tetrahydropyran, 2,2, 5, 5 -tetramethyltetrahydrofuran, and polyethylene glycol.

[0160] In some embodiments, the organic solvent can be an ester-containing solvent, such as butyl acetate. Examples of other suitable ester-containing solvents include, but are not limited to, ethyl acetate, propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, and ethyl, hexyl acetate.

[0161] In some embodiments, the organic solvent can comprise an ether-containing solvent and an ester-containing solvent.

[0162] In some embodiments, the concentration of the organic solvent in the blended mixture can be defined by the volume ratio of the waterborne polyurethane dispersion to the organic solvent in the blended mixture. In some embodiments, the volume ratio of the waterborne polyurethane dispersion to the organic solvent can range from about 1 :2 to about 10: 1, including subranges. For example, in some embodiments, the volume ratio of the waterborne polyurethane dispersion to the organic solvent can range from about 1 :2 to about 5: 1, from about 1 :2 to about 2: 1, from about 1 :2 to about 1 : 1, from about 1 : 1 to about 10: 1, from about 2 : 1 to about 10 : 1 , or from about 5: 1 to about 10 : 1 . As a nonlimiting example, a blended mixture comprising 50 mL waterborne polyurethane dispersion and 50 mL organic solvent has a 1 : 1 volume ratio of waterborne polyurethane dispersion to organic solvent.

[0163] In some embodiments, the concentration of polyethylene oxide in the blended mixture can range from about 0.5 wt% to about 10 wt%, including subranges. For example, in some embodiments, the concentration of polyethylene oxide in the blended mixture can range from about 0.5 wt% to about 7.5 wt%, from about 0.5 wt% to about 5 wt%, from about 0.5 wt% to about 2.5 wt%, from about 1 wt% to about 10 wt%, from about 2.5 wt% to about 10 wt%, or from about 5 wt% to about 10 wt%. In some embodiments, the concentration of polyethylene oxide in the blended mixture can be about 2.5 wt%. Unless specified otherwise, the concentration of the polyethylene oxide in the blended mixture is the mass of polyethylene oxide relative to the sum of the mass of the polyethylene oxide plus the mass of the polyurethane solids in the waterborne polyurethane dispersion. As a non-limiting example, a blended mixture comprising 2.5 grams of polyethylene oxide and 97.5 grams polyurethane solids has a 2.5 wt% polyethylene oxide concentration. [0164] In some embodiments, the method of making fiber 100 comprising protein polyurethane alloy defining core 106 of fiber 100 can comprise coloring the fiber 100. In some embodiments, the fiber 100 can be colored by adding a coloring agent to the blended mixture. For example, in some embodiments, fiber 100 can be dyed by adding a colored dye to the blended mixture. In some embodiments, fiber 100 can be colored with a coloring agent after the blended mixture is extruded into the fiber 100. For example, in some embodiments, fiber 100 can be dyed after the blended mixture is extruded into the fiber 100.

[0165] In some embodiments, fiber 100 can comprise polyurethane not alloyed with protein (i.e., a “non-alloyed polyurethane”) defining core 106 of fiber 100. In such embodiments, fiber 100 is substantially free of protein. In some embodiments, fiber 100 can comprise greater than or equal to 80 wt% non-alloyed polyurethane. In some embodiments, fiber 100 can comprise greater than or equal to 85 wt% non-alloyed polyurethane. In some embodiments, fiber 100 can comprise greater than or equal to 90 wt% non-alloyed polyurethane. In some embodiments, fiber 100 can comprise greater than or equal to 95 wt% non-alloyed polyurethane. In some embodiments, fiber 100 can consist essentially of non-alloyed polyurethane.

[0166] Suitable non-alloyed water-dispersible polyurethanes according to embodiments described herein include, but are not limited to, aliphatic polyurethanes, aromatic polyurethanes, bio-based polyurethanes, or acrylic acid modified polyurethanes. Suitable polyurethanes are commercially available from manufacturers including Lubrizol, Hauthaway, Stahl, and the like. In some embodiments, the polyurethane can be a biopolyurethane. In some embodiments, the polyurethane can be a polyester polyurethane. In some embodiments, the polyurethane can be a polyether polyurethane. In some embodiments, the polyurethane can be a polycarbonate-based polyurethane. In some embodiments, the polyurethane can be an aliphatic polyester polyurethane. In some embodiments, the polyurethane can be an aliphatic polyether polyurethane. In some embodiments, the polyurethane can be an aliphatic polycarbonate polyurethane. In some embodiments, the polyurethane can be an aromatic polyester polyurethane. In some embodiments, the polyurethane can be an aromatic polyether polyurethane. In some embodiments, the polyurethane can be an aromatic polycarbonate polyurethane.

[0167] Exemplary commercial polyurethanes, include but are not limited to L3360 and Hauthane HD-2001 available from C.L. Hauthaway & Sons Corporation, SANCURE™ polyurethanes available from Lubrizol Corporation, BONDTHANE™ polyurethanes, for example UD-108, UD-250, and UD-303 available from Bond Polymers International, EPOTAL® ECO 3702 and EPOTAL® P100 ECO from BASF, and Permutex Evo EX-RC- 2214 (RC-2214) from Stahl.

[0168] In some embodiments, fiber 100 comprising non-alloyed polyurethane defining core 106 of fiber 100 can have a modulus of greater than or equal to about 0.1 cN/tex. In some embodiments, fiber 100 comprising non-alloyed polyurethane defining core 106 of fiber 100 can have a modulus ranging from about 0.1 cN/tex to about 10 cN/tex, including subranges. For example, in some embodiments, the modulus can range from about 0.1 cN/tex to about 5 cN/tex, from about 0.1 cN/tex to about 2 cN/tex, from about 2 cN/tex to about 10 cN/tex, or from about 5 cN/tex to about 10 cN/tex.

[0169] In some embodiments, fiber 100 comprising non-alloyed polyurethane defining core 106 of fiber 100 can have a maximum elongation of greater than or equal to about 100%. In some embodiments, the maximum elongation can range from about 100% to about 1000%, including subranges. For example, in some embodiments, the maximum elongation can range from about 100% to about 750%, from about 100% to about 500%, from about 250% to about 1000%, or from about 500% to about 1000%.

[0170] In some embodiments, fiber 100 comprising non-alloyed polyurethane defining core 106 of fiber 100 can have a tenacity of greater than or equal to about 1 cN/tex. In some embodiments, the tenacity can range from about 1 cN/tex to about 20 cN/tex, including subranges. For example, in some embodiments, the tenacity can range from about 1 cN/tex to about 10 cN/tex, from about 1 cN/tex to about 5 cN/tex, from about 2 cN/tex to about 20 cN/tex, or from about 5 cN/tex to about 20 cN/tex.

[0171] In some embodiments, the fiber 100 comprising non-alloyed polyurethane defining core 106 of fiber 100 can comprise one or more coloring agents. In some embodiments, the coloring agent can be a colored dye, for example a fiber reactive dye, a direct dye, an acid dye, or a natural dye. Exemplary dyes, include but are not limited to, azo structure acid dyes, metal complex structure acid dyes, anthraquinone structure acid dyes, and azo/diazo direct dyes. In some embodiments, the coloring agent can be pigment, for example a lake pigment.

[0172] In some embodiments, fiber 100 comprising non-alloyed polyurethane defining core 106 of fiber 100 can be made by blending a water-dispersible polyurethane and an organic solvent to form a blended mixture, and wet spinning the blended mixture to form the fiber. In alternative embodiments, fiber 100 comprising non-alloyed polyurethane defining core 106 of fiber 100 can be made by blending a water-dispersible polyurethane and an aqueous polyethylene oxide solution to form a blended mixture, and wet spinning the blended mixture to form the fiber. After wet spinning in a coagulation bath, fiber 100 can be removed from the coagulation bath and dried. For example, in some embodiments, fiber 100 can be dried in an oven at a temperature of about 70 °C for 12 to 24 hours. In some embodiments, the coagulation bath for wet spinning fiber 100 can comprise acetic acid and water.

[0173] In some embodiments, the organic solvent can be an ether-containing solvent, such as tetrahydrofuran (THF) or dimethoxymethane. In some embodiments, the ether- containing solvent can be a polyether. Examples of suitable ether-containing solvents include, but are not limited to, tert-amyl ethyl ether, cyclopentyl methyl ether, di-tert- butyl ether, di(propylene glycol) methyl ether, dibutyl ether, diethyl ether, diisopropyl ether, dimethoxy ethane, dimethoxymethane, 1,4-di oxane, ethyl tert-butyl ether, methoxyethane, 2-(2-methoxyethoxy)ethanol, methyl tert-butyl ether, 2- methyltetrahydrofuran, morpholine, propylene glycol methyl ether, tetrahydrofurfuryl alcohol, tetrahydropyran, 2, 2, 5, 5 -tetramethyltetrahydrofuran, and polyethylene glycol.

[0174] In some embodiments, the organic solvent can be an ester-containing solvent, such as butyl acetate. Examples of other suitable ester-containing solvents include, but are not limited to, ethyl acetate, propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, and ethyl, hexyl acetate.

[0175] In some embodiments, the organic solvent can comprise an ether-containing solvent and an ester-containing solvent.

[0176] In some embodiments, the concentration of the organic solvent in the blended mixture can be defined by the volume ratio of the waterborne polyurethane dispersion to the organic solvent in the blended mixture. In some embodiments, the volume ratio of the waterborne polyurethane dispersion to the organic solvent can range from about 1 :2 to about 10: 1, including subranges. For example, in some embodiments, the volume ratio of the waterborne polyurethane dispersion to the organic solvent can range from about 1 :2 to about 5: 1, from about 1 :2 to about 2: 1, from about 1 :2 to about 1 :1, from about 1 : 1 to about 10: 1, from about 2 : 1 to about 10: 1, or from about 5 : 1 to about 10 : 1. As a nonlimiting example, a blended mixture comprising 50 mL waterborne polyurethane dispersion and 50 mL organic solvent has a 1 : 1 volume ratio of waterborne polyurethane dispersion to organic solvent.

[0177] In some embodiments, the concentration of polyethylene oxide in the blended mixture can range from about 0.5 wt% to about 10 wt%, including subranges. For example, in some embodiments, the concentration of polyethylene oxide in the blended mixture can range from about 0.5 wt% to about 7.5 wt%, from about 0.5 wt% to about 5 wt%, from about 0.5 wt% to about 2.5 wt%, from about 1 wt% to about 10 wt%, from about 2.5 wt% to about 10 wt%, or from about 5 wt% to about 10 wt%. In some embodiments, the concentration of polyethylene oxide in the blended mixture can be about 2.5 wt%. Unless specified otherwise, the concentration of the polyethylene oxide in the blended mixture is the mass of polyethylene oxide relative to the sum of the mass of the polyethylene oxide plus the mass of the polyurethane solids in the waterborne polyurethane dispersion. As a non-limiting example, a blended mixture comprising 2.5 grams of polyethylene oxide and 97.5 grams polyurethane solids has a 2.5 wt% polyethylene oxide concentration.

[0178] In some embodiments, the method of making fiber 100 comprising non-alloyed polyurethane defining core 106 of fiber 100 can comprise coloring the fiber 100. In some embodiments, fiber 100 can be colored by adding a coloring agent to the blended mixture. For example, in some embodiments, fiber 100 can be dyed by adding a colored dye to the blended mixture. In some embodiments, fiber 100 can be colored after the blended mixture is wet- spun into the fiber 100. For example, in some embodiments, fiber 100 can be dyed after the blended mixture is wet-spun into the fiber 100.

[0179] In some embodiments, fiber 100 can be formed into a fabric or textile material using a technique such as weaving, knitting, spreading, felting, stitching, and/or crocheting. In some embodiments, a plurality of fibers 100 can be bundled into a fiber bundle comprising the plurality of individual fibers 100. The fiber bundle can comprise two or more individual fibers 100. In some embodiments, the fiber bundle can comprise three or more individual fibers 100. In some embodiments, the fiber bundle can comprise ten or more individual fibers 100. In some embodiments, the fiber bundle can comprise 20 or more individual fibers 100.

[0180] Fibers 100 can be bundled using a technique such as twisting or braiding. In some embodiments, a plurality of fibers 100 can be wet-spun into a fiber bundle using a multi- hole spinneret. FIG. 3 illustrates a fiber bundle 300 comprising a plurality of fibers 100 according to some embodiments.

[0181] The embodiments discussed herein will be further clarified in the following examples. It should be understood that these examples are not limiting to the embodiments described above.

EXAMPLE 1 : Wet Spinning of Raw PUD L3360 without Modification

[0182] Ten grams of polyurethane dispersion (PUD) L3360 from Hauthaway (L3360) was loaded into a 20 mL syringe with a 22 gauge glutaraldehyde cross-linked (GAX) needle and injected into a 30% weight by weight (w/w) acetic acid/water coagulation bath. The extruded L3360 liquid jet solidified and formed non-continuous beads when ejected into the coagulation bath. The extruded L3360 did not form a continuous fiber within the coagulation bath.

EXAMPLE 2: Wet Spinning of PUD L3360/Soy Protein without Modification

[0183] A soy protein isolate (SPI) solution was made by dissolving 3.75 g of SPI (SUPRO® XT 221D-IP; DuPont; available from Solae LLC) into 21 .25 mL of a 0.05 molar (M) sodium hydroxide (NaOH) aqueous solution in a 50 mL glass beaker. The solution was heated to 50 °C and stirred at 600 rotations per minute (rpm) for 30 minutes to dissolve the SPI.

[0184] Then 2.6 g of the SPI solution was added to 10 g of L3360 in a 25 mL beaker and mixed with an overhead agitator for 5 minutes. The weight ratio (w/w) of the dry mass of L3360 to the dry mass of soy protein in the resulting mixture was 90 to 10.

[0185] The resulting L3360/SPI mixture was then loaded into a 20 mL syringe with a 22 gauge GAX needle and injected into a 30% (w/w) acetic acid/water coagulation bath. The extruded L3360/SPI liquid jet solidified and formed non-continuous beads when ejected into the coagulation bath. The extruded L3360/SPI mixture did not form a continuous fiber within the coagulation bath. EXAMPLE 3: Wet spinning of PUD L3360 with THF (Tetrahydrofuran)

[0186] A wet spinning formulati on was prepared by adding 10 mL of tetrahydrofuran (THF) to 10 g of L3360 in a 25 mL beaker. The formulation was mixed with an overhead agitator for 5 minutes. The vi scosity of the formulation was measured using a Discovery HR2 rheometer and Peltier concentric cylinder from TA Instruments with a frequency sweep test from 0.1 rad/s to 100 rad/s. After mixing, the formulation visually appeared uniform and the viscosity increased about 5-fold. Then the mixture was loaded into a 20 mL syringe with a 22 gauge GAX needle and injected into a 30% (w/w) acetic acid/water coagulation bath.

[0187] The extruded formulation solidified when ejected into the coagulation bath and formed continuous fibers. Then, with the continuous fibers still disposed within the coagulation bath, a portion of the solidified fibers were drawn by hand to about 20 times their original length to confirm the solidified fiber had suitable strength and elongation properties. Additionally, drawing the fibers within the coagulation bath can help improve the mechanical strength of the fibers.

[0188] The solidified fibers were then removed from the bath by hand and transferred into a Teflon pan. The Teflon pan and the fibers were placed into an oven for drying at 70 °C overnight. After drying, the fibers looked uniform and continuous. The fibers felt stretchy and did not stick to the Teflon pan or each other after drying.

[0189] Dried fibers were then conditioned overnight in a conditioning chamber (23 °C ± 1 °C, 50% ± 5% relative humidity). After conditioning, the fibers were cut into 40 mm length sections and a piece of tape was attached to each end of individual fiber samples. Then five samples were then tested using an INSTRON® 5965 testing machine fitted with 500 N load cell and 1 kN grips. The samples were pulled to break at 100 mm/min, and the maximum tenacity (strength) and maximum elongation were recorded. The samples had an average tenacity of about 4 cN/tex, an average elongation of about 525%, and an average modulus of 0.9 cN/tex measured at 100% elongation.

EXAMPLE 4A: Wet spinning of PUD L3360/Soy Protein (at 90: 10 ratio) with THF

[0190] An SPI solution was prepared as described in Example 2. [0191] A wet spinning formulation was prepared by adding 2.6 g of the SPI solution, 10 g of L3360 and 10 mL THF to a 25 mL beaker. The formulation was then stirred with an overhead agitator for about 5 minutes. After mixing, the formulation visually appeared uniform and the viscosity increased about 5-fold. The viscosity was measured as described above in Example 3. The weight ratio (w/w) of the dry mass of L3360 to the dry mass of soy protein in the resulting mixture was 90 to 10.

[0192] The resulting mixture was loaded into a 20 mL syringe with a 22 gauge GAX needle and injected into a 30% (w/w) acetic acid/water coagulation bath. The extruded mixture solidified when ejected into the coagulation bath and formed continuous protein polyurethane alloy fibers. Then, with the continuous fibers still disposed within the coagulation bath, a portion of the fibers were drawn by hand to about 14 times their original length to confirm the solidified fiber had suitable strength and elongation properties. Additionally, drawing the fibers within the coagulation bath can help improve the mechanical strength of the fibers.

[0193] The solidified protein polyurethane alloy fibers were then removed from the bath by hand and transferred into a Teflon pan. The Teflon pan and the fibers were placed into an oven for drying at 70 °C overnight. After drying, the fibers looked uniform and continuous. The fibers felt stretchy and did not stick to the Teflon pan or each other after drying.

EXAMPLE 4B: Wet spinning of PUD L3360/Soy Protein (at 95:5 ratio) with THF

[0194] An SPI solution was prepared as described in Example 2.

[0195] A wet spinning formulation was prepared by adding 1.24 g of the SPI solution, 10 g of L3360 and 10 mL THF to a 25 mL beaker. The formulation was then stirred with an overhead agitator for about 5 minutes. After mixing, the formulation visually appeared uniform, and the viscosity increased about 5-fold. The viscosity was measured as described above in Example 3. The weight ratio (w/w) of the dry mass of L3360 to the dry mass of soy protein in the resulting mixture was 95 to 5.

[0196] The resulting mixture was loaded into a 20 mL syringe with a 22-gauge GAX needle and injected into a 30% (w/w) acetic acid/water coagulation bath. The extruded mixture solidified when ejected into the coagulation bath and formed continuous protein polyurethane alloy fibers. Then, with the continuous fibers still disposed within the coagulation bath, a portion of the fibers were drawn by hand to about 14 times their original length to confirm the solidified fiber had suitable strength and elongation properties.

[0197] The solidified protein polyurethane alloy fibers were then removed from the bath by hand and transferred into a Teflon pan. The Teflon pan and the fibers were placed into an oven for drying at 70 °C overnight. After drying, the fibers looked uniform and continuous. The fibers felt stretchy and did not stick to the Teflon pan or each other after drying.

[0198] Dried fibers were then conditioned overnight in a conditioning chamber (23 °C ± 1 °C, 50% ± 5% relative humidity). After conditioning, the fibers were cut into 40 mm length sections and a piece of tape was attached to each end of individual fiber samples. Then five samples of the fibers hand drawn in the coagulation bath were tested using an INSTRON® 5965 machine and the same method as described in Example 3. Additionally, five samples of the fibers not hand drawn in the coagulation bath were tested using the same method. The non-hand-drawn samples had an average tenacity of about 2 cN/tex, an average elongation of about 370%, and an average modulus of about 0.7 cN/tex. The hand-drawn samples had an average tenacity of about 3 cN/tex and an average elongation of about 330%.

EXAMPLE 5: Wet spinning of PUD RC2214/Soy Protein with THF

[0199] An SPI solution was prepared as described in Example 2.

[0200] A wet spinning formulation was prepared by adding 4.37 g of the SPI solution, 10 g of Permutex Evo EX-RC-2214 (RC-2214) from Stahl and 5 mL THF to a 25 mL beaker. Then the formulation was then stirred with an overhead agitator for 5 minutes. After mixing, the formulation visually appeared uniform and the viscosity increased about 5-fold. The viscosity was measured as described above in Example 3. The weight ratio (w/w) of the dry mass of RC-2214 to the dry mass of soy protein solution in the resulting mixture was 90 to 10 (w/w).

[0201] The resulting mixture was loaded into a 20 mL syringe with a 22 gauge GAX needle and injected into a 30% (w/w) acetic acid/water coagulation bath. The extruded mixture solidified when ejected into the coagulation bath and formed continuous protein polyurethane alloy fibers. Then, with the continuous fibers still disposed within the coagulation bath, a portion of the fibers were drawn by hand to about 10 times their original length to confirm the solidified fiber had suitable strength and elongation properties.

[0202] The solidified protein polyurethane alloy fibers were then removed from the bath by hand and transferred into a Teflon pan. The Teflon pan and the fibers were placed into an oven for drying at 70 °C overnight. After drying, the fibers looked uniform and continuous. The fibers felt stretchy and did not stick to the Teflon pan or each other after drying.

EXAMPLE 6: Wet spinning of PUD L3360/Soy with polyethylene oxide (PEO)

[0203] A polyethylene oxide (PEO) solution was made by dissolving 2.5 g polyethylene oxide with a molecular weight of 5 million into 97.5 mL of de-ionized (DI) water in a 100 mL glass beaker. The mixture was then stirred at 100 rpm at room temperature for three days with a stir bar.

[0204] An SPI solution was prepared as described in Example 2.

[0205] A wet spinning formulation was prepared by adding 2.6 g of the SPI solution, 10 g of L3360 and 3.5 g of the PEO solution to a 25 mL beaker. Then the formulation was stirred with an overhead agitator for 5 minutes. After mixing, the formulation appeared uniform and the viscosity increased about 5-fold. The viscosity was measured as described above in Example 3. The weight ratio (w/w) of the dry mass of L3360 to the dry mass of soy protein solution in the resulting mixture was 90 to 10.

[0206] The resulting mixture was then loaded into a 20 mL syringe with a 22 gauge GAX needle and injected into a 30% (w/w) acetic acid/water coagulation bath. The extruded mixture solidified when ejected into the coagulation bath and formed continuous protein polyurethane alloy fibers. It is believed the PEO fully or partially dissolved in the coagulation bath during this process. The solidified protein polyurethane alloy fibers were then removed from the coagulation bath by hand and transferred into a Teflon pan. The Teflon pan and the fibers were placed into an oven for drying at 70 °C overnight. After drying, the fibers looked uniform and continuous. The fibers felt stretchy and did not stick to the Teflon pan or each other after drying. EXAMPLE 7 : Pre-Dyeing of Protein Polyurethane Alloy Fibers

[0207] A first dyed SPI solution was made by dissolving 3.75 g of SPI (SUPRO® XT 221D-IP; DuPont; available from Solae LLC) into 21.25 mL of deionized (DI) water in a 50 mL glass beaker. Then, 100 mg of a blue dye (Reactive Blue-21 available from Khushi Dyechem) was added to the SPI solution. After addition of the dye, 10N NaOH was added until a final NaOH concentration of 0.05N was achieved and the pH of the solution was about 9. The solution was then heated to 50 °C and stirred at 600 rpm for 30 minutes. A second dyed SPI solution was made using the same procedure as the first dyed solution, except 100 mg of a violet dye (Reactive Violet-46, available from Khushi Dyechem) was used.

[0208] Two wet spinning formulations were then prepared as described in Example 4A. The first wet spinning formulation was made with the first dyed SPI solution. The second wet spinning formulation was made with the second dyed SPI solution. Both formulations were wet-spun as described in Example 4A.

[0209] After drying, the sample fibers were cut along their cross-section and the uniformity of the dye within the fibers was analyzed. Based on a visual observation under an optical microscope, the protein polyurethane alloy fibers made with both the first and second dyed SPI solutions displayed a uniform dye distribution throughout the fiber cross-sections. It appeared that the blue dye and the violet dye penetrated the entirety of the fiber cross-sections. These results show that uniform reactive pre-dyeing can be achieved for the protein polyurethane alloy fibers with as low as 5 wt% protein loading of SPI. It is believed that protein polyurethane alloy fibers made with other proteins can be also be uniformly dyed using this dyeing method with other reactive dyes that are soluble in basic conditions.

[0210] After visual inspection under the optical microscope, the sample fibers were soaked in a vial with 20 mL of IX Phosphate Buffered Saline (PBS) (pH 7.48) to evaluate color leeching. After 1 week of soaking at room temperature, the samples showed minimal color leeching into the solution, which indicated the dye sufficiently bonded with the protein polyurethane alloy defining the fibers. EXAMPLE 8: Post-Dyeing of Protein Polyurethane Alloy Fibers

[0211] Samples of wet-spun and dried fibers of Example 3 (wet-spun L3360 fibers without SPI) and Example 4A (wet-spun protein polyurethane alloy fibers comprising L3360 and SPI) were dyed according to the following process.

[0212] The fibers were placed in a beaker and submerged in 30 mL of Dl-water. Then, 150 mg of a blue acid dye (Acid Blue 158 Crude blue, available from Panchmahal Dye Stuff Industries) was added to the beaker. After addition of the dye, the pH was measured and HC1 was added dropwise until a pH of approximately 3.5 was achieved. The dyed mixture, with the fibers submerged, was then left to sit overnight. The next day, the fibers were removed from the beaker and rinsed with warm water to remove unbound dye.

[0213] Based on a visual observation, the fibers of Example 3 did not uptake a significant amount of the blue acid dye. The color of these fibers remained visibly unchanged after dyeing. In contrast, the fibers of Example 4A exhibited a significant color change.

[0214] The dyed sample fibers of Example 4A were cut along their cross-section and the uniformity of the dye was analyzed. Based on a visual observation under an optical microscope, the protein polyurethane alloy fibers of Example 4A displayed a uniform dye distribution throughout the fibers’ cross-section. It appeared that the blue acid dye penetrated the entirety of the fiber cross-sections. These results show that uniform acid post-dyeing can be achieved for the protein polyurethane alloy fibers with as low as 5 wt% protein loading of SPI. It is believed that protein polyurethane alloy fibers made with other proteins can be also be uniformly dyed using this post-dyeing method.

EXAMPLE 9: Wet spinning of PUD L3360/Succinylated-SPI with THF

[0215] Succinylated soy protein isolate (S-SPI) was prepared using the following process. A 10% weight to volume (w/'v) soy protein isolate (SPI) solution was prepared by adding 20 grams of SPI (Solae XT 221D-IP; DuPont) in 180 milliliters (mL) of water to make a 200 mL solution. Then, 54 microliters (pL) of 10N sodium hydroxide (NaOH) was added and the solution was mixed until the SPI was fully dissolved. Once the SPI was fully- dissolved, 200 milligrams (mg) of solid succinic anhydride and 10N sodium hydroxide (NaOH) were added simultaneously to the SPI solution while maintaining a pH of approximately 9 to 9.5. After addition of the succinic anhydride and sodium hydroxide, the solution was incubated at room temperature for 1 hour while being agitated using an overhead agitator. After incubation, the solution was dialyzed against DI water for 24 hours using SnakeSkin ^1M dialysis tubing from Thermo Scientific. After dialysis, the product was lyophilized into a solid protein powder.

[0216] An S-SPI solution was made by dissolving 3.75 g of the S-SPI into 21.25 mL DI water in a 50 mL glass beaker. The solution was heated to 50 °C and stirred at 600 rpm for 30 minutes to dissolve the S-SPI.

[0217] A wet spinning formulation was prepared by adding 1.24 g of the S-SPI solution, 10 g of L3360, and 10 mL THF to a 25 mL beaker. The formulation was then stirred with an overhead agitator for about 5 minutes. After mixing, the formulation visually appeared uniform and the viscosity increased about 5-fold. The viscosity was measured as described above in Example 3. The weight ratio (w/w) of the dry mass of L3360 to the dry mass of S-SPI in the resulting mixture was 95 to 5.

[0218] The resulting mixture was loaded into a 20 mL syringe with a 22-gauge GAX needle and injected into a 60% (w/w) acetic acid/water coagulation bath. The extruded mixture solidified when ejected into the coagulation bath and formed continuous protein polyurethane alloy fibers. The solidified protein polyurethane alloy fibers were then removed from the bath by hand and transferred into a Teflon pan.

[0219] The Teflon pan and the fibers were placed into an oven for drying at 75 °C for 30 minutes. After drying, the fibers looked uniform and continuous. The fibers felt stretchy and did not stick to the Teflon pan or each other after drying.

EXAMPLE 10: Wet spinning of PUD L3360/Cellulase with THF

[0220] A cellulase solution was made by dissolving 4.18 g of cellulase (SUNB AKE® 20 Cellulase available from Suntaq International Limited) into 21.25 mL of DI water in a 50 mL glass beaker. The solution was stirred at 600 rpm for 30 minutes at room temperature to dissolve the cellulase.

[0221] A wet spinning formulation was prepared by adding 1.11 g of the cellulase solution, 10 g of L3360 and 10 mL THF to a 25 mL beaker. The formulation was then stirred with an overhead agitator for about 5 minutes. After mixing, the formulation visually appeared uniform, and the viscosity increased about 5-fold. The viscosity was measured as described above in Example 3. The weight ratio (w/w) of the dry mass of L3360 to the dry mass of cellulase in the resulting mixture was 95 to 5. [0222] The resulting mixture was loaded into a 20 mL syringe with a 22-gauge GAX needle and injected into a 60% (w/w) acetic acid/water coagulation bath. The extruded mixture solidified when ejected into the coagulation bath and formed continuous protein polyurethane alloy fibers. The solidified protein polyurethane alloy fibers were then removed from the bath by hand and transferred into a Teflon pan. The Teflon pan and the fibers were placed into an oven for drying at 75 °C for 30 minutes. After drying, the fibers looked uniform and continuous. The fibers felt stretchy and did not stick to the Teflon pan or each other after drying.

[0223] The dried fibers were then conditioned overnight in a conditioning chamber (23 °C ± 1 °C, 50% ± 5% Relative Humidity). After conditioning, the fibers were cut into 40 mm length sections and a piece of tape was attached to each end of individual fiber samples. Then five samples were tested using an INSTRON® 5965 machine and the same method as described in Example 3. The samples had an average tenacity of about 2 cN/tex and an average elongation of about 360%.

EXAMPLE 11 : Wet spinning of PLID L3360/ 50 KDa r-Collagen fragment (at 80:20 ratio) with THF

[0224] A wet spinning formulation was prepared by adding 0.35 g of the 50 KDa r- Collagen fragment comprising the amino acid sequence listed as SEQ ID NO: 1 to 5 g of L3360 in a 50 mL beaker. The formulation was then stirred with an overhead agitator for about 10 minutes at 250 rpra. After mixing, the formulation visually appeared uniform and the collagen solids appeared fully dissolved. Then, 5 mL of THF was added to the formulation and stirred with the overhead agitator for about 15 minutes at 150 rpm. After mixing, the formulation visually appeared uniform. The weight ratio (w/w) of the dry mass of L3360 to the dry mass of collagen in the resulting mixture was 80 to 20.

[0225] The resulting mixture was loaded into a 20 mL syringe with a 22-gauge GAX needle and injected into a 60% (w/w) acetic acid/water coagulation bath. The extruded mixture solidified when ejected into the coagulation bath and formed continuous protein polyurethane alloy fibers.

[0226] The solidified protein polyurethane alloy fibers were then removed from the bath by hand and transferred into a Teflon pan. The Teflon pan and the fibers were placed into an oven for drying at 70 °C overnight. After drying, the fibers looked uniform and continuous. The fibers felt stretchy and did not stick to the Teflon pan or each other after drying.

[0227] The dried fibers were then conditioned for more than 24 hours in a conditioning chamber (23 °C ± 1 °C, 50% ± 5% relative humidity). After conditioning, the fibers were cut into 40 mm length sections and a piece of tape was attached to each end of individual fiber samples. Then three samples were then tested using an INSTRON® 5965 testing machine and the same method as described in Example 3. The samples had an average tenacity of about 1.5 cN/tex, an average elongation of about 262%, and an average Young’s modulus of 3.4 cN/tex. The Young’s modulus was calculated on the initial linear portion of the tensile curves obtained using the INSTRON® 5965 testing machine using least-squares fit on test data. The steepest slope of the least squares fit was reported as the Young’s modulus for each sample.

EXAMPLE 12: Wet spinning of PLID L3360 with Butyl Acetate

[0228] A wet spinning formulation was prepared by adding 5 mL of butyl acetate to 10 g of L3360 in a 25 mL beaker. The formulation was mixed with an overhead agitator for 5 minutes. After mixing, the formulation visually appeared uniform. Then the mixture was loaded into a 20 mL syringe with a 22-gauge GAX needle and injected into a 60% (w/w) acetic acid/water coagulation bath. The extruded formulation solidified when ejected into the coagulation bath and formed continuous fibers.

[0229] The solidified fibers were then removed from the bath by hand and transferred into a Teflon pan. The Teflon pan and the fibers were placed into an oven for drying at 70 °C overnight. After drying, the fibers looked uniform and continuous. The fibers felt stretchy and did not stick to the Teflon pan or each other after drying.

[0230] The dried fibers were then conditioned for more than 24 hours in a conditioning chamber (23 °C ± 1 °C, 50% ± 5% relative humidity). After conditioning, the fibers were cut into 40 mm length sections and a piece of tape was attached to each end of individual fiber samples. Then three samples were then tested using an INSTRON® 5965 testing machine and the same method as described in Example 3. The samples had an average tenacity of about 1.5 cN/tex, an average elongati on of about 353%, and an average Young’s modulus of 2.0 cN/tex. The Young’s modulus was calculated as described in Example 11 . EXAMPLE 13: Wet spinning of PUD L3360/Soy Protein (at 95:5 ratio) with Butyl Acetate

[0231] An SPI solution was prepared as described in Example 2

[0232] A wet spinning formulation was prepared by adding 1.24 g of the SPI solution, 10 g of L3360, and 5 mL butyl acetate to a 25 mL beaker. The formulation was then stirred with an overhead agitator for about 5 minutes. After mixing, the formulation visually appeared uniform. The weight ratio (w/w) of the dry mass of L3360 to the dry mass of soy protein in the resulting mixture was 95 to 5.

[0233] The resulting mixture was loaded into a 20 mL syringe with a 22-gauge GAX needle and injected into a 60% (w/w) acetic acid/water coagulation bath. The extruded mixture solidified when ejected into the coagulation bath and formed continuous protein polyurethane alloy fibers.

[0234] The solidified protein polyurethane alloy fibers were then removed from the bath by hand and transferred into a Teflon pan. The Teflon pan and the fibers were placed into an oven for drying at 70 °C overnight. After drying, the fibers looked uniform and continuous. The fibers felt stretchy and did not stick to the Teflon pan or each other after drying.

[0235] The dried fibers were then conditioned for more than 24 hours in a conditioning chamber (23 °C ± 1 °C, 50% ± 5% relative humidity ). After conditioning, the fibers were cut into 40 mm length sections and a piece of tape was attached to each end of individual fiber samples. Then three samples were then tested using an INSTRON® 5965 testing machine and the same method as described in Example 3. The samples had an average tenacity of about 1.0 cN/tex, an average elongation of about 169%, and an average Young’s modulus of 2.7 cN/tex. The Young’s modulus was calculated as described in Example 11.

EXAMPLE 14: Wet spinning of PUD L3360/Soy Protein (at 95:5 ratio) with Diethyl Ether

[0236] An SPI solution was prepared as described in Example 2

[0237] A wet spinning formulation was prepared by adding 1.49 g of the SPI solution, 12 g of L3360 and 10 mL diethyl ether to a 25 mL beaker. The formulation was then stirred with an overhead agitator for about 5 minutes. After mixing, the formulation visually appeared uniform. The weight ratio (w/w) of the dry mass of L3360 to the dry mass of soy protein in the resulting mixture was 95 to 5.

[0238] The resulting mixture was loaded into a 20 mL syringe with a 22-gauge GAX needle and injected into a 60% (w/w) acetic acid/water coagulation bath. The extruded mixture solidified when ejected into the coagulation bath and formed continuous protein polyurethane alloy fibers.

[0239] The solidified protein polyurethane alloy fibers were then removed from the bath by hand and transferred into a Teflon pan. The Teflon pan and the fibers were placed into an oven for drying at 70 °C overnight. After drying, the fibers looked uniform and continuous. The fibers felt stretchy and did not stick to the Teflon pan or each other after drying.

[0240] The dried fibers were then conditioned for more than 24 hours in a conditioning chamber (23 °C ± 1 °C, 50% ± 5% relative humidity). After conditioning, the fibers were cut into 40 mm length sections and a piece of tape was attached to each end of individual fiber samples. Then three samples were then tested using an INSTRON® 5965 testing machine and the same method as described in Example 3. The samples had an average tenacity of about 1.3 cN/tex, an average elongation of about 326%, and an average Young’s modulus of 2.5 cN/tex. The Young’s modulus was calculated as described in Example 11.

EXAMPLE 15: Wet spinning of PUD HYDRAN® WLF-286BP with THF

[0241] A wet spinning formulation was prepared by adding 8 mL of THF to 10 mL of HYDRAN® WLF-286BP in a 25 mL beaker. The formulation was mixed with an overhead agitator at 200 rpm for 2 minutes. After mixing, the formulation visually appeared uniform.

[0242] The resulting mixture was loaded into a 20 mL syringe with a 22-gauge GAX needle and injected into a 60% (w/w) acetic acid/water coagulation bath. The extruded mixture solidified when ejected into the coagulation bath and formed continuous polyurethane fibers.

[0243] The solidified polyurethane fibers were then removed from the bath by hand and transferred into a Teflon pan. The Teflon pan and the fibers were placed into an oven for drying at 70 C overnight. After drying, the fibers looked uniform and continuous. The fibers felt stretchy and did not stick to the Teflon pan or each other after drying.

EXAMPLE 16: Wet spinning of PUD L3360/Bovine Serum Albumin (at 95:5 ratio) with THF

[0244] A Bovine Serum Albumin (BSA) solution was prepared by adding 1 g of BSA lyophilized powder from Sigma Aldrich to 9 g of water in a 20 mL vial. The vial was placed in a water bath at 50 °C and mixed at 600 rpm for 30 minutes with a stir bar.

[0245] A wet spinning formulation was prepared by adding 1.84 g of the BSA solution described above to 10 g of L3360 and 10 mL of THF in a 20 mL beaker. The formulation was then stirred with an overhead agitator for 5 minutes at 250 rpm. After mixing, the formulation visually appeared uniform. The weight ratio (w/w) of the dry mass of L3360 to the dry mass of BSA in the resulting mixture was 95 to 5.

[0246] The resulting mixture was loaded into a 20 mL syringe with a 22-gauge GAX needle and injected into a 60% (w/w) acetic acid/water coagulation bath. The extruded mixture solidified when ejected into the coagulation bath and formed continuous protein polyurethane alloy fibers.

[0247] The solidified protein polyurethane alloy fibers were then removed from the bath by hand and transferred into a Teflon pan. The Teflon pan and the fibers were placed into an oven for drying at 70 C for 1 hour. After drying, the fibers looked uniform and continuous. The fibers felt stretchy and did not stick to the Teflon pan or each other after drying.

[0248] The dried fibers were then conditioned for more than 24 hours in a conditioning chamber (23 °C ± 1 °C, 50% ± 5% relative humidity). After conditioning, the fibers were cut into 40 mm length sections and a piece of tape was attached to each end of individual fiber samples. Then three samples were then tested using an INSTRON® 5965 testing machine and the same method as described in Example 3. The samples had an average tenacity of about 2.4 cN/tex, an average elongation of about 368%, and an average Young’s modulus of 1.4 cN/tex. The Young’s modulus was calculated as described in Example 11 . EXAMPLE 17: Wet spinning of PUD HYDRAN® WLF-286BP/ SPI at (95:5 ratio) with THF

[0249] An SPI solution was prepared as described in Example 2

[0250] A wet spinning formulation was prepared by adding 1.1 g of the SPI solution and 8.9 g of HYDRAN® WLF-286BP to a 25 mL beaker. The formulation was then stirred with an overhead agitator for about 5 minutes. After mixing, the formulation visually appeared uniform. The weight ratio (w/w) of the dry mass of HYDRAN® WLF-286BP to the dry mass of soy protein in the resulting mixture was 95 to 5. Then, 8 mL of THF was added to the formulation in the beaker and stirred with the overhead agitator for about 15 minutes at 150 rpm.

[0251] The resulting mixture was loaded into a 20 mL syringe with a 22-gauge GAX needle and injected into a 60% (w/w) acetic acid/water coagulation bath. The extruded mixture solidified when ejected into the coagulation bath and formed continuous protein polyurethane alloy fibers.

[0252] The solidified protein polyurethane alloy fibers were then removed from the bath by hand and transferred into a Teflon pan. The Teflon pan and the fibers were placed into an oven for drying at 70 C for 1 hour. After drying, the fibers looked uniform and continuous. The fibers felt stretchy and did not stick to the Teflon pan or each other after drying.

[0253] While various embodiments have been described herein, they have been presented by way of example, and not limitation. It should be apparent that adaptations and modifications are intended to be within the meaning and range of equivalents of the disclosed embodiments, based on the teaching and guidance presented herein. It therefore will be apparent to one skilled in the art that various changes in form and detail can be made to the embodiments disclosed herein without departing from the spirit and scope of the present disclosure. The elements of the embodiments presented herein are not necessarily mutually exclusive, but can be interchanged to meet various situations as would be appreciated by one of skill in the art.

[0254] Embodiments of the present disclosure are described in detail herein with reference to embodiments thereof as illustrated in the accompanying drawings, in which like reference numerals are used to indicate identical or functionally similar elements. References to “one embodiment,” “an embodiment,” “some embodiments,” “in certain embodiments,” etc., indicate that the embodiment described can include a particular feature, structure, or characteristic, but ever}' embodiment can not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

[0255] The examples are illustrative, but not limiting, of the present disclosure. Other suitable modifications and adaptations of the variety of conditions and parameters normally encountered in the field, and which would be apparent to those skilled in the art, are within the spirit and scope of the disclosure.

[0256] It is to be understood that the phraseology or terminology used herein is for the purpose of description and not of limitation. The breadth and scope of the present disclosure should not be limited by any of the above-described exemplary embodiments, but should be defined in accordance with the following claims and their equivalents.

SEQUENCES

SEQ ID NO: 1 : Collagen Fragment

DVKSGVAVGGLAGYPGPAGPPGPPGPPGTSGHPGSPGSPGYQGPPGEPGQAGPSG

PPGPPGAIGPSGPAGKDGESGRPGRPGERGLPGPPGIKGPAGIPGFPGMKGHRGFD

GRNGEKGETGAPGLKGENGLPGENGAPGPMGPRGAPGERGRPGLPGAAGARGN

DGARGSDGQPGPPGPPGTAGFPGSPGAKGEVGPAGSPGSNGAPGQRGEPGPQGH

AGAQGPPGPPGINGSPGGKGEMGPAGIPGAPGLMGARGPPGPAGANGAPGLRGG

AGEPGKNGAKGEPGPRGERGEAGIPGVPGAKGEDGKDGSPGEPGANGLPGAAGE

RGAPGFRGPAGPNGIPGEKGPAGERGAPGPAGPRGAAGEPGRDGVPGGPGMRG

MPGSPGGPGSDGKPGPPGSQGESGRPGPPGPSGPRGQPGVMGFPGPKGNDGAPG

KNGERGGPGGPGPQGPPGKNGETGPQGPPGPTGPGGDKGDTGPPGPQGLQGLPG

TGGPPGENGKPGEPGPKGDAGAPGAPGGKGDAGAPGERGPPAIAGIGGEKAGGF

APYYG