Field of the invention

The invention relates to a functional amphiphilic waterborne macro-RAFT agent and using this amphiphilic waterborne macro-RAFT agent for the surfactant-free RAFT-mediated emulsion polymerization. The waterborne macro-RAFT agent is prepared by polymerization-induced self-assembly (PISA) strategy in aqueous phase. Then a series of surfactant-free RAFT latexes were obtained by using this type of waterborne macro-RAFT agent. All the targeting polymers have good stability, high solid content and a size range of 100 nm - 300 nm. After crosslinked with ADH, the enhanced and preferred mechanical properties were obtained. The resulting dispersions can be applied in a wide range of applications, such as architectural coatings, adhesives, construction area, paper manufacture as well as furniture coatings.

Background of the invention

Emulsion polymerization has been commercialized for several decades, the resulting product, is called latex. Latexes have been applied in a wide range of industrial applications, such as architectural coatings, adhesives, construction area, paper manufacture as well as furniture coatings.

In the specific areas of coatings, adhesives, cement area as well as paper manufacture, crosslinkers are induced for the desired mechanical properties. Crosslinkers are commonly used in these fields. However, the crosslinking efficiency is restricted in conversional emulsion polymerization and the preferred mechanical properties can only be obtained by high level of crosslinker amount.

Another common problem encountered in conversional emulsion polymerization is the carboxylic acid induced in the formulation of emulsion polymerization may lead to some negative impacts on some applications, such as freeze-thaw stability.

Therefore, it would be desirable to have a methodology to prepare the surfactant-free, carboxylic acid-free (or very low amount, i.e. less than 5 wt%) and high crosslinking efficiency latex to satisfy our desired industrial applications requirements, such as a high theoretical molecular weight (M _n > 60,000), high solid content, good freeze/thaw stability and a size range of 100 nm - 300 nm.

Reversible addition-fragmentation chain transfer (RAFT) polymerization, a reversible deactivation radical polymerization (RDRP), has grown into one of the most facile techniques for the manufacture of all types of well-defined polymeric architectures since 1998. Over the past decades, RAFT polymerization technology in waterborne dispersed systems has drawn a great deal of researchers’ attention and led to the revolution in terms of accessible polymeric architecture, controllable molecular weight, low dispersity, tailored functionality as well as specific morphology.

CN 10469338613 discloses a process for the preparation of a cross-linkable composition comprising a block copolymer [A] _x [B] _y mediated by a xanthate small RAFT agent and a polymer P. (A) monomer units derived from at least one water-soluble monomer and (B) monomer units derived from at least one ethylenically unsaturated monomer, respectively; and where y > x. Polymer P is prepared in the presence of [A] _x [B] _y via emulsion polymerization. However, [A] _x [B] _y block copolymer is prepared via RAFT solution polymerization. There is no disclosure that the [A] _x [B] _y block copolymer does not contain carboxylic acid. In addition, there is no disclosure about the low dispersity (£> < 1.50) from the [A] _x [B] _y block copolymer and so it fails to show a good control of RAFT. Moreover, the disclosure also fails to show the ability to produce the waterborne surfactant-free polymers (P) with a high theoretical number average molecular weight (M _n > 60,000), a high solid content (> 40 wt %) as well as the size range of 100 nm - 300 nm.

It is surprisingly found that the present invention provides a good protocol for the production of desired latexes with a wide range of monomers. The functional amphiphilic macro-RAFT agent is prepared in aqueous phase with the low dispersity (£> < 1.30). By using such a functional amphiphilic macro-RAFT agent, a series of high solid content (> 40 wt %), good stability, carboxylic acid-free (or very low amount, i.e. less than 5 wt%), surfactant-free latexes are obtained with a size range of 100 nm to 300 nm.

Summary of the invention:

One object of the present invention is to provide a functional amphiphilic waterborne macro- RAFT agent. The amphiphilic waterborne macro-RAFT agent is prepared in aqueous phase.

The waterborne macro-RAFT agent is synthesized with (A) at least one water soluble monoethylenically unsaturated monomer, (B) at least one water soluble monoethylenically unsaturated monomer with at least one crosslinkable functional group, (C) at least one hydrophobic monoethylenically unsaturated monomer, and (D) at least one water soluble Chain Transfer Agent (“CTA”), wherein the at least one water-soluble Chain Transfer Agent has a general structure of Formula I: S

_E i_ _{s-c-s-Ra Formu|a} ! wherein R ¹ is selected from -CH2COOX, or -CH2COOR ³ , or -C(R ⁴ )(R ⁵ )COOX, or - C(R ⁴ )(R ⁵ )COOR ³ , or -C(R ⁴ )(CN)(CH ₂ CH ₂ COOX), or -C(R ⁴ )(CN)(CH ₂ CH ₂ COOR ³ ) wherein X is a hydrogen atom, an alkali metal, an alkaline earth metal, an organic ammonium salts, an ammonium; and R ³ , R ⁴ , R ⁵ are selected from an optionally substituted aryl, an optionally substituted alkyl, an optionally substituted (alkoxy)alkyl, an optionally substituted (alkoxycarbonyl)alkyl, an optionally substituted (carboxylate)alkyl, an optionally substituted carbamoyl (-C0N(alkyl)2); R ² is selected from an optionally substituted aryl, or an optionally substituted alkyl, or an alkyl such as -C _n H2n+i, or -(CH2) _n COOY, or -(CH2) _n COOR ⁶ wherein n is an integer >1, Y is a hydrogen atom, an alkali metal, an alkaline earth metal, an organic ammonium salts, an ammonium; and R ⁶ is selected from an optionally substituted aryl, an optionally substituted alkyl, an optionally substituted (alkoxy)alkyl, an optionally substituted (alkoxycarbonyl)alkyl, an optionally substituted (carboxylate)alkyl, an optionally substituted carbamoyl (-CON(alkyl)2).

In a preferred embodiment, the wmacro-RAFT agent may have a structure of Formula II: Poly(A _x -co-B _y )-b-Poly(Cz) Formula II wherein it is synthesized with: i) 30 to 90 mol % (A) a water soluble monoethylenically unsaturated monomer which may contain at least one functional group selected from a carboxylic acid group, a carboxylic acid anhydride group, a sulfonic acid group, a phosphoric acid, or their salts thereof; ii) 1 to 60 mol % (B) a water soluble monoethylenically unsaturated monomer with at least one crosslinkable functional group selected from a diacetone group, an acetoacetoxyl group, a ureido group, an oxazoline group, and a carbodiimide group; iii) 1 to 50 mol % (C) unsaturated hydrophobic monomers, selecting from n-butyl acrylate, styrene, ethyl acrylate, methyl acrylate, and so forth wherein i), ii) and iii) add to 100 %, x is an integer from 1 to 200, y is an integer from 1 to 100 and z is an integer from 1 to 100.

Another object of the present invention is to provide a polymer latex using the amphiphilic waterborne macro-RAFT agent. The functional waterborne macro-RAFT agent demonstrates the ability to produce a series of surfactant-free stable latex with high solid content and a size range of 100 nm to 300 nm.

A third object of the present invention is to provide a polymer composition with the abovementioned polymer latex and a post-added chemical for crosslinking.

DETAILED DESCRIPTION OF THE INVENTION

Unless otherwise specified, all terms/terminology/nomenclatures used herein have the same meaning as commonly understood by the skilled person in the art to which this invention belongs to.

Expressions “a”, “an” and “the”, when used to define a term, include both the plural and singular forms of the term. The term “polymer” or “polymers”, as used herein, includes both homopolymer(s), that is, polymers prepared from a single reactive compound, and copolymer(s), that is, polymers prepared by reaction of at least two polymer forming reactive, monomeric compounds.

The term “derivative” means compound that is derived from a similar compound with one or more hydrogen atoms been substituted with a function group, such as a halogen, a carboxylate group, an alkoxyl group, etc.

The designation (meth)acrylate and similar designations are used herein as an abbreviated notation for “acrylate and/or methacrylate”.

The term “water soluble” means a chemical that has a water solubility of at least 1.0 g/L at 20 °C under 1 atm. If a chemical is reactive with sodium hydroxide, to form a salt, the water solubility refers to solubility of the salt form, otherwise, the water solubility refers to the solubility of itself.

The term “hydrophobic monomers” means a monomer that has a water solubility less than 1.0 g/L at 20 °C under 1 atm. If a monomer is reactive with sodium hydroxide to form a salt, the water solubility refers to solubility of the salt form, otherwise, the water solubility refers to the solubility of itself.

The term “particle size” means the size of a particle measured with Dynamic Light Scattering (DLS), unless otherwise specified.

All percentages and ratios denote weight percentages and weight ratios unless otherwise specified.

One object of the present invention is to provide a waterborne macro-RAFT agent is synthesized with (A) at least one water soluble monoethylenically unsaturated monomer, (B) at least one water soluble monoethylenically unsaturated monomer with at least one crosslinkable functional group, (C) at least one hydrophobic monoethylenically unsaturated monomer, and (D) at least one water soluble Chain Transfer Agent (“CTA”), wherein the at least one water-soluble Chain Transfer Agent has a general structure of Formula I:

, __ll _ , k ' ' ‘ ^{S 1} Formula I wherein R ¹ is selected from -CH2COOX, or -CH2COOR ³ , or -C(R ⁴ )(R ⁵ )COOX, or - C(R ⁴ )(R ⁵ )COOR ³ , or -C(R ⁴ )(CN)(CH ₂ CH ₂ COOX), or -C(R ⁴ )(CN)(CH ₂ CH ₂ COOR ³ ) wherein X is a hydrogen atom, an alkali metal, an alkaline earth metal, an organic ammonium salts, an ammonium; and R ³ , R ⁴ , R ⁵ are selected from an optionally substituted aryl, an optionally substituted alkyl, an optionally substituted (alkoxy)alkyl, an optionally substituted (alkoxycarbonyl)alkyl, an optionally substituted (carboxylate)alkyl, an optionally substituted carbamoyl (-CON(alkyl)2); R ² is selected from an optionally substituted aryl, or an optionally substituted alkyl, or an alkyl such as -C _n H2n+i, or -(CH2) _n COOY, or -(CH2) _n COOR ⁶ wherein n is an integer >1, Y is a hydrogen atom, an alkali metal, an alkaline earth metal, an organic ammonium salts, an ammonium; and R ⁶ is selected from an optionally substituted aryl, an optionally substituted alkyl, an optionally substituted (alkoxy)alkyl, an optionally substituted (alkoxycarbonyl)alkyl, an optionally substituted (carboxylate)alkyl, an optionally substituted carbamoyl (-CON(alkyl)2).

The at least one water soluble monoethylenically unsaturated monomer (A) may be monoethylenically unsaturated monomers containing at least one group selected from the group consisting of carboxyl, carboxylic anhydride and sulfonic acid, phosphoric acid and their salts thereof.

Particularly, the at least one water soluble monoethylenically unsaturated monomer (A) includes, but is not limited to, monoethylenically unsaturated carboxylic acids, such as 2- acrylamido-2-methylpropane-sulfonic acid (AMPS), (meth)acrylic acid, itaconic acid, fumaric acid, citraconic acid, sorbic acid, cinnamic acid, glutaconic acid and maleic acid; monoethylenically unsaturated carboxylic anhydride, such as itaconic acid anhydride, fumaric acid anhydride, citraconic acid anhydride, sorbic acid anhydride, cinnamic acid anhydride, glutaconic acid anhydride and maleic acid anhydride^ sodium-styrenesulfonate (SSS) or styrene sulfonic acid.

In a preferred embodiment according to the present invention, 2-acrylamido-2-methylpropane- sulfonic acid (AMPS) or its salt, acrylic acid, methacrylic acid, itaconic acid, sodium- styrenesulfonate (SSS) or a mixture thereof is preferred as the at least one water soluble monoethylenically unsaturated monomer.

In a more preferred embodiment according to the present invention, 2-acrylamido-2- methylpropane-sulfonic acid (AMPS) or its slat and sodium-styrenesulfonate (SSS) are preferred as the at least one water soluble monoethylenically unsaturated monomer.

The at least one water soluble monoethylenically unsaturated monomer (A) may account for, based on the total moles of monomers for the synthesis of the waterborne macro-RAFT agent, 30 to 90 mol %, preferably 35 to 85 mol %, more preferably 40 to 85 mol %, and most preferably 40 to 80 mol %.

The at least one water soluble monoethylenically unsaturated monomer with at least one crosslinkable functional group (B) may contain a functional group selected from a diacetone group, an acetoacetoxyl group, a ureido group, an oxazoline group, a carbodiimide group or any mixture thereof.

The at least one water soluble monoethylenically unsaturated monomer with at least one hydroxy group includes, but not limited to, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, hydroxypropyl methacrylate, 2-hydroxyethyl methacrylate, 3-phenoxy-2-hydroxy-propyl methacrylate, glycerol monomethacrylate, N-(2- hydroxypropyl)methacrylamide and N-hydroxyethyl acrylamide.

The at least one water soluble monoethylenically unsaturated monomer with at least one diacetone group includes, but not limited to, diacetone acrylamide (DAAM), hydroxymethyl diacetone acrylamide.

The at least one water soluble monoethylenically unsaturated monomer with at least one acetoacetoxyl group includes, but not limited to, acetoacetoxyethyl methacrylate (AAEM), acetoacetoxyethyl acrylate (AAEA), 2-[(E)-but-2-enoyl]oxyethyl 3-oxobutanoate, 2- methylprop-2-enyl 3-oxobutanoate, (E)-but-2-en-1-yl 3-oxobutanoate, prenyl 3-oxobutanoate and 2,3-dimethyl-but-2-enyl acetoacetate.

The at least one water soluble monoethylenically unsaturated monomer with at least one ureido group includes, but not limited to, ureido methylacrylate, ureido acrylate, chemicals with the following structure:

The at least one water soluble monoethylenically unsaturated monomer with at least one oxazoline group includes, but not limited to, 2-vinyl-2-oxazoline, 2-ethylene-4-methyl-2- oxazoline, 2-ethylene-5-methyl-2-oxo, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2- oxazoline and 2-isopropenyl-5-ethyl-2-oxazoline.

The at least one water soluble monoethylenically unsaturated monomer with at least one carbodiimide group includes, but not limited to, 1-vinylcarbodiimide, N-ethyl-N'-[(E)-1-methyl- 2-(methoxycarbonyl)vinyl]carbodiimide, N-propyl-N'-[(E)-1-methyl-2- (methoxycarbonyl)vinyl]carbodiimide, 1-cyclohexyl-3-(1-phenylvinyl)carbodiimide, 1-phenyl-3- (l-phenylvinyl)carbodiimide, N-phenyl-N'-(4-vinylphenyl)carbodiimide, and N-phenyl-N'- ethenylcarbodiimide.

In a preferred embodiment, the functional group is selected from a diacetone group, an acetoacetoxyl group, an oxazoline group or any mixture thereof.

In a more preferred embodiment, the at least one water soluble monoethylenically unsaturated monomer with at least one crosslinkable functional group (B) is selected from diacetone acrylamide (DAAM), acetoacetoxyethyl methacrylate (AAEM), ureidomethacrylate (UMA) or any mixture thereof.

The at least one water soluble monoethylenically unsaturated monomer with at least one crosslinkable functional group (B) may account for, based on the total moles of monomers for the synthesis of the waterborne macro-RAFT agent, 1 to 60 mol %, preferably 1 to 50 mol %, more preferably 3 to 45 mol %, and most preferably 3 to 40 mol %. The at least one hydrophobic monoethylenically unsaturated monomer (C) may be selected from the group consisting of (meth)acrylate monomers, (meth)acrylonitrile monomers, styrene monomers, vinyl alkanoate monomers and monoethylenically unsaturated di-and tricarboxylic ester monomers.

Particularly, the (meth)acrylate monomers may be Ci-Ci9-alkyl (meth)acrylates, for example, but not limited to, methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, 2- ethylhexyl (meth)acrylate, cyclohexyl (meth)acrylate, n-octyl (meth)acrylate, n-decyl (meth)acrylate, n-dodecyl (meth)acrylate (i.e. lauryl (meth)acrylate), tetradecyl (meth)acrylate, oleyl (meth)acrylate, palmityl (meth)acrylate, stearyl (meth)acrylate, isobornyl (meth)acrylate, benzyl (meth)acrylate, phenyl (meth)acrylate and a mixture thereof.

Particularly, the styrene monomers may be unsubstituted styrene or Ci-Ce-alkyl substituted styrenes, for example, but not limited to, styrene, a-methylstyrene, ortho-, meta- and paramethylstyrene, ortho-, meta- and para-ethylstyrene, o,p-dimethylstyrene, o,p-diethylstyrene, ispropylstyrene, o-methyl-p-isopropylstyrene or any mixture thereof.

Particularly, the vinyl alkanoate monomers may be vinyl esters of C2-Cn-alkanoic acids, for example, but not limited to, vinyl acetate, vinyl propionate, vinyl butanoate, vinyl valerate, vinyl hexanoate, vinyl versatate or a mixture thereof.

In addition, the monoethylenically unsaturated di-and tricarboxylic ester monomers may be full esters of monoethylenically unsaturated di-and tricarboxylic acids, for example, but not limited to, diethyl maleate, dimethyl fumarate, ethyl methyl itaconate, or any mixture thereof.

In a preferred embodiment according to the present invention, one or more Ci-Ci2-alkyl (meth)acrylates, such as methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate and 2-ethylhexyl (meth)acrylate, styrene or a mixture thereof is chosen as the at least one hydrophobic monoethylenically unsaturated monomer (C).

The at least one hydrophobic monoethylenically unsaturated monomer (C) may account for, based on the total moles of monomers for the synthesis of the waterborne macro-RAFT agent, 1 to 50 mol %, preferably 5 to 45 mol %, more preferably 10 to 40 mol % and most preferably 15 to 35 mol %.

The at least one water-soluble Chain Transfer Agent has a general structure of Formula I: _Formu | _a | wherein R ¹ is selected from -CH2COOX, or -CH2COOR ³ , or -C(R ⁴ )(R ⁵ )COOX, or - C(R ⁴ )(R ⁵ )COOR ³ , or -C(R ⁴ )(CN)(CH ₂ CH ₂ COOX), or -C(R ⁴ )(CN)(CH ₂ CH ₂ COOR ³ ) wherein X is a hydrogen atom, an alkali metal, an alkaline earth metal, an organic ammonium salts, an ammonium; and R ³ , R ⁴ , R ⁵ are selected from an optionally substituted aryl, an optionally substituted alkyl, an optionally substituted (alkoxy)alkyl, an optionally substituted (alkoxycarbonyl)alkyl, an optionally substituted (carboxylate)alkyl, an optionally substituted carbamoyl (-CON(alkyl)2); R ² is selected from an optionally substituted aryl, or an optionally substituted alkyl, or an alkyl such as -C _n H2n+i, or -(CH2) _n COOY, or -(CH2) _n COOR ⁶ wherein n is an integer >1, Y is a hydrogen atom, an alkali metal, an alkaline earth metal, an organic ammonium salts, an ammonium; and R ⁶ is selected from an optionally substituted aryl, an optionally substituted alkyl, an optionally substituted (alkoxy)alkyl, an optionally substituted (alkoxycarbonyl)alkyl, an optionally substituted (carboxylate)alkyl, an optionally substituted carbamoyl (-CON(alkyl)2).

In the present invention, an "alkyl" refers to a monovalent group which is generated after a chain or cyclic aliphatic hydrocarbon (alkane) loses a hydrogen atom. In the cases of a chain alkyl group, the alkyl group is generally represented by CkH2k+i- (wherein, k is a positive integer). A chain alkyl group may be a straight chain or branched chain. A cyclic alkyl group may be consisted of a cyclic structure. A cyclic alkyl group may have a structure in which a chain alkyl group is linked to the cyclic structure. An alkyl group may have an arbitrary natural number of carbon atoms. Preferably, an alkyl group has 1 to 30 carbon atoms.

In a preferred embodiment, a "lower alkyl" is preferred, which refers to an alkyl group having a relatively small number of carbon atoms. Preferably, a lower alkyl is a C1-10 alkyl group. More preferably, a lower alkyl is a C1-5 alkyl group. Further preferably, a lower alkyl is a C1-3 alkyl group. For instance, specific examples include methyl, ethyl, propyl and isopropyl.

In the present specification, an "alkoxy" refers to a group in which an oxygen atom is bound to the aforementioned alkyl group. That is, when the alkyl group is represented by R-, the alkoxy refers to a group represented by RO-. A chain alkoxy group may be a straight chain or branched chain. Cyclic alkoxy may be composed only of a cyclic structure, or may have a structure formed from a cyclic structure further linked with chain alkyl. The number of carbon atoms in the alkoxy may be any natural number. The number of carbon atoms is preferably from 1 to 30.

In the present invention, a “hydroxyalkyl” refers to a group in which a hydroxyl group is bonded to the aforementioned alkyl group. That is, when the alkyl group is represented by -R, the alkoxy refers to a group represented by -ROH. A chain hydroxyalkyl group may be a straight chain or branched chain. Cyclic hydroxyalkyl may be composed only of a cyclic structure, or may have a structure formed from a cyclic structure further linked with chain alkyl. The number of carbon atoms in the alkoxy may be any natural number. The number of carbon atoms is preferably from 1 to 30.

In the present invention, an "aryl" refers to a group which is generated after a hydrogen atom, which is bound to a ring of an aromatic hydrocarbon, is removed. Specifically, for example, an aryl includes a phenyl group, naphthyl group, or anthracenyl group. In a preferred embodiment, a "substituted aryl" is preferred, which refers to a group which is generated after a substituent bind to an aryl group.

In the present invention, a “carboxylate” refers to a “alkylcarboxyl”. An "alkylcarboxyl" refers to a group in which a carboxyl group is bound to the aforementioned alkyl group. That is, when the alkyl group is represented by R-, the alkylcarboxyl refers to a group represented by RCOO-. A chain alkylcarboxyl group may be a straight chain or branched chain. A cyclic alkylcarboxyl group may be composed only of a cyclic structure, or may have a structure formed from a cyclic structure further linked with chain alkyl. The number of carbon atoms in the alkylcarboxyl may be any natural number. The number of carbon atoms is preferably from 1 to 30. Additionally, in the present invention, a “carbonyl” refers to a “alkylcarbonyl”. An "alkylcarbonyl" refers to a group in which a carbonyl group is bound to the aforementioned alkyl group. That is, when the alkyl group is represented by R-, the alkylcarbonyl refers to a group represented by RCO-. A chain alkylcarbonyl group may be a straight chain or branched chain. Cyclic alkylcarbonyl may be composed only of a cyclic structure, or may have a structure formed from a cyclic structure further linked with chain alkyl. The number of carbon atoms in the alkylcarbonyl may be any natural number. The number of carbon atoms is preferably from 1 to 30.

In a preferred embodiment, if a “carboxylate” is presented, a “lower alkylcarboxyl" and/or a “lower alkylcarbonyl” is preferred as the R ² and/or R ³ . A "lower alkylcarboxyl" refers to an alkylcarboxyl group having relatively fewer carbon atoms. The lower alkylcarboxyl is preferably C1-10 alkylcarboxyl. A "lower alkylcarbonyl" refers to an alkylcarbonyl group having relatively fewer carbon atoms. The lower alkylcarbonyl is preferably C1-10 alkylcarbonyl.

In the present invention, an “acetoacetyl” group means a group with the following structure: wherein R ^a is a Ci to C22 alkylene group and R ^b is a Ci to C22 alkyl group. Preferably, R ^a is a Ci to C4 alkylene group and R ^b is a Ci to C4 alkyl group, and more preferably, R ^a is methylene (-CH2-) and R ^b is methyl (-CH3).

In the present invention, a “ureido” group means a group with the following structure:

In the present invention, a “carbodiimide” means a group with the following structure: R

'N=N

Wherein R is an alkyl group. In a preferred embodiment, at least one water soluble Chain Transfer Agent (“CTA”) (D) inlcudes, but not limited to, dibenzyl trithiocarboante (DBTTC), 1-phenylprop-2-yl phenyldithioacetate; 1 -phenylethyl phenyldithioacetate, cumyl phenylditioacetate, 2- phenylprop-2-yl dithiobenzoate; 1-phenylprop-2-yl p-bromodithiobenzoate; 1 -phenylethyl dithiobenzoate; 2-cyanoprop-2-yl dithiobenzoate; 4-cyanopentanoic acid dithiobenzoate; 1- acetoxyethyl dithiobenzoate; hexakis(thiobenzoylthiomethyl)benzene; 1,4- bis(thiobenzoylthiomethyl)benzene; 1,2,4,5-tetrakis(thiobenzoylthiomethyl)benzene; ethoxycarbonylmethyl dithioacetate; 2-(ethoxycarbonyl)prop-2-yl dithiobenzoate; tert-butyl dithiobenzoate; 1 ,4-bis(2-thiobenzoylthioprop-2-yl)benzene; 4-cyano-4- (thiobenzoylthio)pentanoic acid; dibenzyl trithiocarbonate; carboxymethyl dithiobenzoate; s- benzyl diethoxyphosphinyldothioformate; 2,4,4-trimethylpent-2-yl dithiobenzoate; 2- (ethoxycarboxyl)prop-2-yl dithiobenzoate; 2-phenylprop-2-yl 1-dithionaphthalate; 2- phenylprop-2-yl 4-chlorodithiobenzoate and 4-((((2-carboxyethyl)thio)carbonothioyl)thio)-4- cyanopentanoic acid or its salt.

The at least one water soluble Chain Transfer Agent (“CTA”) (D) may account for, based on the total dry weight of the waterborne macro-RAFT agent, 1 to 30 wt %, preferably 1 to 20 wt %, more preferably 0.1 to 10.0 wt %.

In a preferred embodiment, the waterborne macro-RAFT agent may have a structure of Formula II:

Poly(A _x -co-B _y )-b-Poly(Cz) Formula II wherein it is synthesized with: i) 30 to 90 mol % (A) a water soluble monoethylenically unsaturated monomer which may contain at least one functional group selected from a carboxylic acid group, a carboxylic acid anhydride group, a sulfonic acid group, a phosphoric acid, or its salt thereof; ii) 1 to 60 mol % (B) a water soluble monoethylenically unsaturated monomer with at least one crosslinkable functional group selected from a diacetone group, an acetoacetoxyl group, a ureido group, an oxazoline group, an epoxy group, and a carbodiimide group; iii) 1 to 50 mol % (C) unsaturated hydrophobic monomers, selecting from n-butyl acrylate, styrene, ethyl acrylate, methyl acrylate, and so forth wherein, i), ii) and iii) add to 100%, x is an integer from 1 to 200, y is an integer from 1 to 100 and z is an integer from 1 to 100.

In a preferred embodiment, the waterborne macro-RAFT agent may have a structure of Formula II:

Poly(A _x -co-B _y )-b-Poly(Cz) Formula II wherein it is synthesized with: i) 35 to 85 mol % (A) a water soluble monoethylenically unsaturated monomer which may contain at least one functional group selected from a carboxylic acid group, a carboxylic acid anhydride group, a sulfonic acid group, a phosphoric acid, or its salt thereof; ii) 1 to 50 mol % (B) a water soluble monoethylenically unsaturated monomer with at least one crosslinkable functional group selected from a diacetone group, an acetoacetoxyl group, a ureido group, an oxazoline group, an epoxy group, and a carbodiimide group; iii) 5 to 45 mol % (C) unsaturated hydrophobic monomers, selecting from n-butyl acrylate, styrene, ethyl acrylate, methyl acrylate, and so forth wherein, i), ii) and iii) add to 100%, x is an integer from 10 to 150, y is an integer from 1 to 80 and z is an integer from 5 to 80.

In a more preferred embodiment, the waterborne macro-RAFT agent may have a structure of Formula II:

Poly(A _x -co-B _y )-b-Poly(Cz) Formula II wherein it is synthesized with: i) 40 to 85 mol % (A) a water soluble monoethylenically unsaturated monomer which may contain at least one functional group selected from a carboxylic acid group, a carboxylic acid anhydride group, a sulfonic acid group, a phosphoric acid, or its salt thereof; ii) 3 to 45 mol % (B) a water soluble monoethylenically unsaturated monomer with at least one crosslinkable functional group selected from a diacetone group, an acetoacetoxyl group, a ureido group, an oxazoline group, an epoxy group, and a carbodiimide group; iii) 10 to 40 mol % (C) unsaturated hydrophobic monomers, selecting from n-butyl acrylate, styrene, ethyl acrylate, methyl acrylate, and so forth wherein, i), ii) and iii) add to 100 %, x is an integer from 15 to 100, y is an integer from

1 to 60 and z is an integer from 5 to 60.

In a most preferred embodiment, the waterborne macro-RAFT agent may have a structure of Formula II:

Poly(A _x -co-B _y )-b-Poly(Cz) Formula II wherein it is synthesized with: i) 40 to 80 mol % (A) a water soluble monoethylenically unsaturated monomer which may contain at least one functional group selected from a carboxylic acid group, a carboxylic acid anhydride group, a sulfonic acid group, a phosphoric acid, or its salt therefore; ii) 3 to 40 mol % (B) a water soluble monoethylenically unsaturated monomer with at least one crosslinkable functional group selected from a diacetone group, an acetoacetoxyl group, a ureido group, an oxazoline group, an epoxy group, and a carbodiimide group; iii) 15 to 35 mol % (C) unsaturated hydrophobic monomers, selecting from n-butyl acrylate, styrene, ethyl acrylate, methyl acrylate, and so forth wherein, i), ii) and iii) add to 100 %, x is an integer from 20 to 50, y is an integer from 1 to 30 and z is an integer from 5 to 20.

Preferably, x + y shall be larger than z (i.e. x + y > z), for all the embodiments.

The polymerization process for obtaining block copolymers are proceeded in aqueous phase, it is a typical polymerization-induced self-assembly (PISA) process. For the polymerization P(A-co-B), monomer A, monomer B, initiator and small RAFT agent are water-soluble. By adding monomer C, the block copolymer drives self-assembly in aqueous phase.

The final assemblies may have a particle size in the range of 55 to 250 nm, preferably in the range of 75 to 200 nm.

In a different aspect of this invention, the waterborne macro-RAFT agent has been used in emulsion polymerization. In the emulsion polymerization process, many polymerizable monomers known to the skilled person in the art in the field of emulsion polymerization may be used. It’s surprising that the emulsion polymer synthesized with the waterborne macro-RAFT agent has good stability, high solid content and a size range of 100 - 300 nm.

The emulsion polymerization in the present invention may apply at least one hydrophobic monoethylenically unsaturated monomer may be selected from, but not limited to, (meth)acrylate monomers, (meth)acrylonitrile monomers, styrene monomers, vinyl alkanoate monomers, monoethylenically unsaturated di-and tricarboxylic ester monomers or a mixture thereof.

Particularly, the (meth)acrylate monomers may be Ci-Ci9-alkyl (meth)acrylates, for example, but not limited to, methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, 2- ethylhexyl (meth)acrylate, cyclohexyl (meth)acrylate, n-octyl (meth)acrylate, n-decyl (meth)acrylate, n-dodecyl (meth)acrylate (i.e. lauryl (meth)acrylate), tetradecyl (meth)acrylate, oleyl (meth)acrylate, palmityl (meth)acrylate, stearyl (meth)acrylate, isobornyl (meth)acrylate, benzyl (meth)acrylate, phenyl (meth)acrylate and a mixture thereof.

Particularly, the styrene monomers may be unsubstituted styrene or Ci-Ce-alkyl substituted styrenes, for example, but not limited to, styrene, a-methylstyrene, ortho-, meta- and paramethylstyrene, ortho-, meta- and para-ethylstyrene, o,p-dimethylstyrene, o,p-diethylstyrene, ispropylstyrene, o-methyl-p-isopropylstyrene or any mixture thereof.

Particularly, the vinyl alkanoate monomers may be vinyl esters of C2-Cn-alkanoic acids, for example, but not limited to, vinyl acetate, vinyl propionate, vinyl butanoate, vinyl valerate, vinyl hexanoate, vinyl versatate or a mixture thereof.

Particularly, the monoethylenically unsaturated di-and tricarboxylic ester monomers may be full esters of monoethylenically unsaturated di-and tricarboxylic acids, for example, but not limited to, diethyl maleate, dimethyl fumarate, ethyl methyl itaconate, dihexyl succinate, didecyl succinate or any mixture thereof.

In a preferred embodiment according to the present invention, one or more Ci-Ci2-alkyl (meth)acrylates, such as methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, styrene or a mixture thereof is chosen as the at least one hydrophobic monoethylenically unsaturated monomer.

The at least one hydrophobic monoethylenically unsaturated monomer may be in an amount of at least 70 wt %, all based on the total weight of all monomers used in the emulsion polymerization.

The emulsion polymerization in the present invention may apply at least one additional hydrophilic monoethylenically unsaturated monomer may be monoethylenically unsaturated monomers containing at least one functional group selected from, but not limited to, a group consisting of carboxyl, carboxylic anhydride, sulfonic acid, phosphoric acid, hydroxyl and amide.

Particularly, the hydrophilic monoethylenically unsaturated monomer include, but are not limited to, monoethylenically unsaturated carboxylic acids, such as (meth)acrylic acid, itaconic acid, fumaric acid, citraconic acid, sorbic acid, cinnamic acid, glutaconic acid and maleic acid; monoethylenically unsaturated carboxylic anhydrides, such as itaconic acid anhydride, fumaric acid anhydride, citraconic acid anhydride, sorbic acid anhydride, cinnamic acid anhydride, glutaconic acid anhydride and maleic acid anhydride; monoethylenically unsaturated amides, such as (meth)acrylamide, N-methylol (meth)acrylamide, N,N-dimethylacrylamide (DMA), 2- hydroxyethyl (meth)acrylamide, dimethylaminoethylmethacrylamide; hydroxyalkyl esters of monoethylenically unsaturated carboxylic acids, such as hydroxyethyl (meth)acrylate and hydroxypropyl (meth)acrylate; and other monomers, such as glycerol (meth)acrylate, or a mixture thereof.

In a preferred embodiment according to the present invention, acrylic acid, methacrylic acid, acrylamide or a mixture thereof is the preferred at least one water soluble monoethylenically unsaturated monomer.

The hydrophilic monoethylenically unsaturated monomer can be in an amount of at least 0.1 % by weight and no more than 20.0 % by weight, preferably no more than 15 % by weight, more preferably no more than 10.0 % by weight, and mostly preferably no more than 5.0 % by weight, based on the total weight of all monomers used in the emulsion polymerization.

The monomers for the synthesis of the polymer emulsion may further comprise one or more crosslinking monomers. The crosslinking monomers can be chosen from, but not limited to, di- or poly-isocyanates, polyaziridines, polycarbodiimide, polyoxazolines, glyoxals, malonates, triols, epoxy molecules, organic silanes, carbamates, diamines and triamines, hydrazides, carbodiimides and multi-ethylenically unsaturated monomers. In the present invention, suitable crosslinking monomers include, but not limited to, glycidyl (meth)acrylate, N- methylol(meth)acrylamide, (isobutoxymethyl)acrylamide, vinyltrialkoxysilanes such as vinyltrimethoxysilane; alkylvinyldialkoxysilanes such as dimethoxymethylvinylsilane; (meth)acryloxyalkyl-trialkoxysilanes such as (meth)acryloxyethyltrimethoxysilane, (3- acryloxypropyl)trimethoxysilane and (3-methacryloxypropyl)trimethoxysilane; allyl (meth)acrylate, diallyl phthalate, 1,4-butylene glycol dimethacrylate, 1,2-ethylene glycol dimethacrylate, 1,6-hexanediol diacrylate, divinyl benzene or any mixture thereof.

The monomers could further include other suitable polymerizable compounds, which include, but not limited to, olefins, such as ethylene, propene, cloropropene, butene, 1-decene; dienes, such as butadiene, isoprene, cloroprene, norbornadiene; N-vinyl compounds, such as N-vinyl- 2-pyrrolidone (NVP), N-vinyl formamide, N-vinyl acetamide, N-vinyl isopropylamide, N-vinyl-N- methyl acetamide and N-vinyl caprolactam.

Surfactants may also be polymerizable surfactants, also called a reactive surfactant, containing at least one ethylenically unsaturated functional group. Suitable polymerizable surfactants include, but are not limited to, allyl polyoxyalkylene ether sulfate salts such as sodium salts of allyl polyoxyethylene alkyl ether sulfate, allyl alkyl succinate sulfonate salts, allyl ether hydroxyl propanesulfonate salts such as sodium salts, polyoxyethylene styrenated phenyl ether sulfate salts such as ammonium salts, for example DKS Hitenol® AR 1025 and DKS Hitenol® AR 2020, polyoxyethylene alkylphenyl ether sulfate ammonium salts, polyoxyethylene allyloxy nonylphenoxypropyl ether, and phosphate acrylates such as SI POM ER® PAM 100, phosphate acrylates such as SI POM ER® PAM 200, etc.

However, in the present invention, it’s preferred that no surfactant is used in the emulsion polymerization. Such a process is referred to as “surfactant-free emulsion polymerization” and the resulted emulsion polymer is usually termed as “surfactant-free emulsion polymer”.

An organic base and/or inorganic base may be added into the polymerization system as a neutralizer during the polymerization or after the completion of such process. Suitable neutralizers include, but are not limited to, inorganic bases such as ammonia, sodium/potassium hydroxide, sodium/potassium carbonate or a combination. Organic bases such as dimethyl amine, diethyl amine, triethyl amine, monoethanolamine, triethanolamine, or a mixture thereof can also be used as the neutralizer. Among others, sodium hydroxide, ammonia, dimethylaminoethanol, 2-amino-2-methyl-1-propanol or any mixture thereof are preferable as the neutralizer useful for the polymerization process. Upon the addition of a neutralizer, pH of the final polymer emulsion shall be in the range of 5.0 to 10.0, preferably in the range of 5.0 to 8.0.

The polymer latex could be further formulated with crosslinkers. Suitable crosslinkers may include, but not limited to, dihydrazide, such as, oxalic dihydrazide, malonic dihydrazide, succinic dihydrazide, glutaric dihydrazide, adipic dihydrazide, sebacic dihydrazide, maleic dihydrazide, fumaric dihydrazide, itaconic dihydrazide and/or isophthalic dihydrazide or mixture thereof. Particular preferences are adipic dihydrazide, sebacic dihydrazide, and isophthalic dihydrazide, most preferably are adipoyl dihydrazide. Suitable compounds containing hydroxylamine groups or oxime ether groups are specified for example in WO 9325588. Other suitable crosslinkers can be the compounds containing amino groups include ethylenediamine, propylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, polyethyleneimines, partly hydrolyzed polyvinylformamides, cyclohexanediamine, and xylylenediamine or mixture thereof.

Examples

The present invention is further demonstrated and exemplified in the examples, however, without being limited to the embodiments described in the examples.

Materials

4-((((2-Carboxyethyl)thio)carbonothioyl)thio)-4-cyanopent anoic acid, from (Boron Molecular)

2-Acrylamido-2-methylpropane-sulfonic acid (noted as “AMPS”), from (Sigma-Aldrich)

Sodium hydrogen carbonate (noted as NaHCCh), from (Sigma-Aldrich)

Sodium persulfate (noted as “SPS”), from (Sigma-Aldrich) n-Butyl acrylate (noted as “BA”), from (Sigma-Aldrich)

Styrene, (noted as “St”), from (Sigma-Aldrich)

Methyl methacrylate (noted as “MMA”), from (Sigma-Aldrich)

2-Ethylhexyl acrylate (noted as “2-EHA”), from (Sigma-Aldrich)

Vinyl acrylate (noted as “ Ac”), from (Sigma-Aldrich)

Adipic acid dihydrazide (noted as “ADH”), from (Sigma-Aldrich)

St, BA, 2-EHA, MMA and VAc were purified by a basic aluminium oxide column.

4-((((2-Carboxyethyl)thio)carbonothioyl)thio)-4-cyanopent anoic acid, AMPS, DAAM, ADH, SPS and NaHCOs were used as received without further purification.

Methods and Characterizations

Gel Permeation Chromatography (GPC): The number average molecular weight (/W„) and dispersity (£>) determined by gel permeation chromatography (GPC) with DMF as the eluent. The GPC instrument comprises a Shimadzu LC-20AT pump and a Shimadzu differential refractometer RID-20A. GPC system is equipped with a guard column (WAT054415) and three Waters SEC columns (WAT044238, WAT044226 and WAT044235, 300 mm x 7.8 mm). The eluent (DMF) contained LiBr (10 mM). The flow rate was 1 mL/min (40 °C). The column system was calibrated with poly(methyl methacrylate) (PMMA) standard and polystyrene (PSt) standard.

Dynamic Light Scattering (DLS):

DLS results were recorded at 25 °C on a Malvern Zetasizer Nano equipment comprising an avalanche photodiode (APD) detector. The sample was measured at a concentration of 0.3 - 0.5 mg mL ^-1 in DI water by using a 4 mW He-Ne laser at a wavelength of 633 nm. The measurement gives an average value of the second order cumulant analysis (mean of fits), i.e. Z average. The "mean of fits" is an average, intensity-weighted hydrodynamic particle diameter in nm.

Nuclear Magnetic Resonance (NMR):

The monomer conversion was determined by ¹ H NMR. The ¹ H NMR spectra were recorded on 400 MHz Bruker instrument. DMSO-cfe (62.50), D2O (64.70) and MeOD (63.30) were used as the solvents for the NMR analysis, and the chemical shift was calibrated using tetramethylsilane (TMS) as the internal standard.

Dynamic Mechanical Analysis (DMA):

Latex films were prepared under room temperature for 2 weeks (temperature: 23 °C; humidity: 50 %). The targeting films were prepared with dimensions of 1 mm thickness. DMA measurements were performed by using an Anton Paar MCR302 rheometer with the oscillation mode (strain: 0.05 %; rate: 10 rad/s).

Examples for DAAM-based amphiphilic waterborne macro-RAFT agents

Examples S 1

Preparation of P(AMPSNa-co-DAAM)-b-PBA-TTC Waterborne macro-RAFT Agent 1

0.20 g (0.65 x 10 ^-3 mol) of 4-((((2-Carboxyethyl)thio)carbonothioyl)thio)-4-cyanopentano ic acid , 2.70 g (13.01 x 10' ³ mol) of AMPS, 0.55 g (3.25 x 10' ³ mol) of DAAM, 24.05 g (5 wt %, 14.31 x io ^-3 mol) of NaHCOs solution and water were added in a 100 mL round bottle. After 30 min deoxygenation by argon, then the mixture was heated under 85 °C and added SPS (1 wt %, 1.55 g, 0.07 x 10' ³ mol) solution by a syringe. After 2 h, 0.83 g (6.51 x 10' ³ mol) of BA monomer and second part of SPS (1 wt %, 1.55 g, 0.07 x 10 ^-3 mol) solution were added by a syringe. The reaction was continued for another 2 h. The monomer conversion achieved higher than 98.0 %. The molecular weight was determined by GPC, M _n = 12.53 kg/mol, £> (Mw/Mn) = 1.15. And, the size was 161.6 nm with a PDI of 0.089. Examples S 2

Preparation of P(AMPSNa-co-DAAM)-b-PBA-TTC Waterborne macro-RAFT Agent 2

0.20 g (0.65 x 10 ^-3 mol) of 4-((((2-Carboxyethyl)thio)carbonothioyl)thio)-4-cyanopentano ic acid , 2.70 g (13.01 x 10' ³ mol) of AMPS, 1.10 g (6.51 x 10' ³ mol) of DAAM, 24.05 g of NaHCOs (5 wt %, 14.31 x 10 ^-3 mol) solution and water were added in a 100 mL round bottle. After 30 min deoxygenation by argon, then the mixture was heated under 85 °C and added SPS (1 wt %, 1.55 g, 0.07 x 10' ³ mol) solution by a syringe. After 2 h, 0.83 g (6.51 x 10' ³ mol) BA monomer and second part of SPS (1.0 wt %, 1.55 g, 0.07 x 10 ^-3 mol) solution were added by a syringe. The reaction was continued for another 2 h. The monomer conversion achieved higher than 98.0 %. The molecular weight was determined by GPC, M _n = 13.60 kg/mol, £> (Mw/Mn) = 1.22. And, the size was 145.0 nm with a PDI of 0.041.

Examples S 3

Preparation of P(AMPSNa-co-DAAM)-b-PBA-TTC Waterborne macro-RAFT Agent 3

0.20 g (0.65 x 10 ^-3 mol) of 4-((((2-Carboxyethyl)thio)carbonothioyl)thio)-4-cyanopentano ic acid , 2.70 g (13.01 x 10' ³ mol) of AMPS, 1.65 g (9.76 x 10’ ³ mol) of DAAM, 24.05 g of NaHCOs (5.0 wt %, 14.31 x 10 ^-3 mol) solution were added in a 100 mL round bottle. After 30 min deoxygenation by argon, then the mixture was heated under 85 °C and added SPS (1.0 wt %, 1.55 g, 0.07 x 10' ³ mol) solution by a syringe. After 2 h, BA (0.83 g, 6.51 x 10' ³ mol) monomer and second part of SPS (1.0 wt %, 1.55 g, 0.07 x 10 ^-3 mol) solution were added by a syringe. The reaction was continued for another 2 h. The monomer conversion achieved higher than 98.0 %. The molecular weight was determined by GPC, M _n = 16.81 kg/mol, £> (Mw/Mn) = 1.19. And, the size was 132.9 nm with a PDI of 0.052.

Examples S 4

Preparation of P(AMPSNa-co-DAAM)-b-PBA-TTC Waterborne macro-RAFT Agent 4

0.20 g (0.65 x 10 ^-3 mol) of 4-((((2-Carboxyethyl)thio)carbonothioyl)thio)-4-cyanopentano ic acid , 2.70 g (13.01 x 10' ³ mol) of AMPS, 2.20 g (13.03 x 10’ ³ mol) of DAAM, 24.05 g of NaHCOs (5.0 wt %, 14.31 x 10 ^-3 mol) solution were added in a 100 mL round bottle. After 30 min deoxygenation by argon, then the mixture was heated under 85 °C and added SPS (1.0 wt %, 1.55 g, 0.07 x 10' ³ mol) solution by a syringe. After 2 h, BA (0.83 g, 6.51 x 10' ³ mol) monomer and second part of SPS (1.0 wt %, 1.55 g, 0.07 x 10 ^-3 mol) solution were added by a syringe. The reaction was continued for another 2 h. The monomer conversion achieved higher than 98.0 %. The molecular weight was determined by GPC, M _n = 16.72 kg/mol, £> (Mw/Mn = 1.23. And, the size was 132.5 nm with a PDI of 0.015.

Examples S 5

Preparation of P(APMSNa)-b-PBA-TTC Waterborne macro-RAFT Agent 5

0.10 g (0.33 x 10' ³ mol) of 4-((((2-Carboxyethyl)thio)carbonothioyl)thio)-4-cyanopentano ic acid, 1.35 g (6.51 x 10- ³ mol) of AMPS, NaHCO ₃ (5.0 wt %, 12.0 g, 7.14 x 10- ³ mol) solution and water were added in a 100 mL round bottle. After 30 min deoxygenation by argon, the mixture was heated under 85 °C and added SPS (1.0 wt %, 0.77 g, 0.03 x 10 ^-3 mol) solution by a syringe. After 2 h, add BA (0.42 g, 3.25 x 10 ^-3 mol) monomer and second part of SPS (1.0 wt %, 0.77 g, 0.03 x 10 ^-3 mol) solution by a syringe. The reaction was continued for another 2 h. The monomer conversion achieved higher than 98.0 %. The molecular weight was determined by GPC, M _n = 10.40 kg/mol, £> (Mw/Mn) = 1.16. And, the size was 100.1 nm with a PDI of 0.017.

Examples for latex synthesis by using functional amphiphilic waterborne macro-RAFT agents

Examples

Examples 1

Preparation of PBA latex by using Example S2 (P(AMPSNa-co-DAAM)-b-PBA-TTC Waterborne macro-RAFT Agent 2)

15.00 g (16.57 wt %) of P(AMPS-co-DAAM)-b-PBA-TTC waterborne macro-RAFT agent, 24.16 g of BA and 18.89 g of water were added in a 250 mL four-necked round bottle. After 30 min deoxygenation by argon, the mixture was heated under 85 °C and SPS (1.0 wt %, 1.50 g) solution was injected by a syringe. The reaction was conducted for another 4 h. The particle size was 202.7 nm and the PDI was 0.012 respectively. The solid content was 43.8 wt %.

Examples 2

Preparation of P(St-co-BA) latex by using Example S2 (P(AMPSNa-co-DAAM)-b-PBA-TTC Waterborne macro-RAFT Agent 2)

15.00 g (16.53 wt %) of P(AMPSNa-co-DAAM)-b-PBA-TTC waterborne macro-RAFT agent, 16.07 g of BA, 9.79 g of St and 20.66 g of water were added in a 100 mL round bottle. After 30 min deoxygenation by argon, the mixture was heated under 85 °C and SPS (1.0 wt %, 1.50 g) solution was injected by a syringe. The reaction was conducted for 6 h. At 4 h, add the second part of SPS (1 wt %, 1.50 g). The particle size was 172.2 nm and the PDI was 0.069 respectively. The solid content was 43.1 wt %.

Examples 3

Preparation of P(BA-co-MMA) latex by using Example S2 (P(AMPSNa-co-DAAM)-b-PBA-TTC Waterborne macro-RAFT Agent 2)

15.00 g (15.87 wt %) of P(AMPSNa-co-DAAM)-b-PBA-TTC waterborne macro-RAFT agent, 23.15 g of BA, 3.01 g of MMA and 20.87 g of water were added in a 250 mL four-necked round bottle. After 30 min deoxygenation by N2, the mixture was heated under 85 °C and SPS (1.0 wt %, 1.43 g) solution was injected by a syringe. The reaction was conducted for 4 h. The particle size was 214.0 nm and the PDI was 0.017 respectively. The solid content was 44.2 wt %. Examples 4

Preparation of P(BA-co-Vac) latex by using Example S2 (P(AMPSNa-co-DAAM)-b-PBA-TTC Waterborne macro-RAFT Agent 2)

6.00 g (16.87 wt %) of P(AMPSNa-co-DAAM)-b-PBA-TTC waterborne macro-RAFT agent, 9.82 g of BA, 1.10 g of VAc and 9.00 g of water were added in a 100 mL round bottle. After 30 min deoxygenation by argon, the mixture was heated under 85 °C and SPS (1.0 wt %, 0.61 g) solution was injected by a syringe. The reaction was conducted for 4 h. The particle size was 213.6 nm and the PDI was 0.010 respectively. The solid content was 42.0 wt %.

Examples 5

Preparation of P(EHA-co-MMA) latex by using Example S2 (P(AMPSNa-co-DAAM)-b-PBA- TTC Waterborne macro-RAFT Agent 2)

5.00 g (16.27 wt %) of P(AMPSNa-co-DAAM)-b-PBA-TTC waterborne macro-RAFT agent, 11.37 g of EHA, 1.03 g of MMA and 11.49 g of water were added in a 100 mL round bottle. After 30 min deoxygenation by argon, the mixture was heated under 85 °C and SPS (1.0 wt %, 0.49 g) solution was injected by a syringe. The reaction was conducted for 4 h. The particle size was 208.4 nm and the PDI was 0.013 respectively. The solid content was 42.9 wt %.

Examples 6

Preparation of P(EHA-co-BA) latex by using Example S2 (P(AMPSNa-co-DAAM)-b-PBA-TTC Waterborne macro-RAFT Agent 2)

6.00 g (16.87 wt %) of P(AMPS-co-DAAM)-b-PBA-TTC waterborne macro-RAFT agent, 4.91 g of BA, 9.41 g of 2-EHA and 13.24 g of water were added in a 100 mL round bottle. After 30 min deoxygenation by argon, the mixture was heated under 85 °C and SPS (1.0 wt %, 0.61 g) solution was injected by a syringe. The reaction was conducted for 4 h. The particle size was 225.2 nm and the PDI was 0.07 respectively. The solid content was 44.3 wt %.

Examples 7

Preparation of P(St-co-BA) latex by using Example S5 (PAMPSNa-b-PBA-TTC Waterborne macro-RAFT Agent 5)

10.00 g (13.96 wt %) of PAMPSNa-b-PBA-TTC waterborne macro-RAFT agent, 11.91 g of BA, 7.01 g of St and 13.87 g of water were added in a 100 mL round bottle. After 30 min deoxygenation by argon, the mixture was heated under 85 °C and SPS (1 wt %, 1.07 g) solution was injected by a syringe. At 4 h, the second part of SPS solution (1.0 wt %, 1.07 g) was injected by a syringe. The reaction was conducted for 6 h. The particle size was 240.7 nm and the PDI was 0.076 respectively. The solid content was 43.5 wt %.

A stoichiometric amount of ADH solution was added in each of the latex. The molar ratio of DAAM/ADH is around 2/1. Specifically, in example 2, 0.42 g of 10 wt % of ADH aqueous solution was added to 10.0 g of a latex and stirred vigorously to obtain the final composition. Dynamic Mechanical Analysis (DMA) at 20 °C:

Table-1 Storage Modulus at 20 °C

Latex E’ at 20 °C (MPa)

1 0.29

1 + ADH 1.03

2 2.81

2 + ADH 15.4

3 0.42

3 + ADH 4.59

4 0.68

4 + ADH 2.95

5 0.15

5 + ADH 1.86

6 0.19

6 + ADH 0.98

Table-2 Storage Modulus at 20 °C

Latex E’ at 20 °C (MPa)

2 2.81

2 + ADH 15.40

7 1.00

7 + ADH 1.05

The DMA results presented in Table-1 show that all the films made with the composition of ADH in the present invention have the higher storage modulus. More specifically, according to the data listed in Table 2, the DAAM-based RAFT latexes indicate higher storage modulus with respect to non-DAAM containing latex.

Stability Test

The resulting polymer latexes are subjected to stability test.

Freeze-Thaw Stability (F/T Stability)

Freeze-thaw stability test is performed by exposing the latex samples in a - 5 °C freezer for 24 hours, and then allowing them to thaw at ambient temperature for another 24 h. After each cycle, the latex samples are analysed by visual observation on physical changes, e.g. flow behaviour, coagulum. After 3 cycles, if no significant changes are observed, it is the demonstration that the latex samples can pass the freeze-thaw stability test. P stands for pass and F means failure. And, the freeze-thaw stability test results are listed in Table 3. Table-3 Freeze-Thaw Stability (F/T Stability)

It’s obvious that the latex synthesized according to the present invention show good freezethaw stability.