WATER SOLUBLE CHAIN TRANSFER AGENTS BACKGROUND OF THE INVENTION

0001] The disclosed technology relates to water soluble, or partially water soluble, hain transfer agents for preparing water soluble polymers by Reversible Addition- ragmentation Chain Transfer ("RAFT") polymerization in an aqueous medium. 0002] Many references for Reversible Addition-Fragmentation Chain Transfer "RAFT") polymerizations involving Chain Transfer Agents ("CTA") teach polymerzations done in organic solvents such as toluene or 1,4-dioxane in order to prepare water-based polymers (meaning either water soluble polymers or emulsions). While uch organic solvents are certainly sufficient for polymerization, they pose both a ealth risk and a fire hazard, and thus large scale commercialization using such solents is not desired. Further, when such organic solvent are employed for making water soluble polymers, the organic solvent must be stripped to provide a useful wa- er-soluble polymer, which adds additional hazard as well as time and resources. 0003] A more preferred way of synthesizing water soluble polymers is to make he polymers directly in water with a water soluble CTA. This has been demonstrated many times in the academic literature. In one report, Matsuno, Ryosuke; Goto, Yusuke; Konno, Tomohiro; Takai, Madoka; Ishihara, Kazuhiko Journal ofNanosci- nce and Nanotechnology (2009), 9(1), 3S8-36S, researchers used CTA-Na that was ydrophobically associated to a modified quantum dot (QD) in water to build a QD upported biopolymer. In this example the researchers took advantage of the surfacant properties of CTA-Na to help stabilize the QD and subsequent polymer that was rown out from the core.

0004] What is needed is an economically feasible way to control polymerization f water soluble monomers such as AMPS™, acrylamide, acrylic acid, etc., in aqueous olutions.

SUMMARY OF THE INVENTION

0005] The disclosed technology, therefore, solves the problem of performing liv- ng polymerizations in aqueous media by providing water soluble CTAs.

0006] What we are proposing here, is a water soluble CTA-acid, or a water solble CTA-acid salt made by reacting a CTA-acid with a suitable base, such as sodium hydroxide, or an amine, to produce a water soluble RAFT agent. The molecule is hen used to controllably polymerize any water-soluble monomers directly in water. The resulting polymers are of a predetermined molecular weight with a low polydis- ersity. Since the polymerization is living, water soluble block copolymers and other nteresting geometries can be envisioned such as star and comb polymers. These materials have potential applications in any formulation that might require a water oluble polymer of defined molecular weight and shape such as for example, paints nd coatings, personal and home care, energy exploration and refinery applications, ncluding but not limited to, water treatment applications, drilling fluids, paraffin nhibiting applications, cementing applications, completion applications, and fuel ransportation applications and for improving refinery and oilfield operational effiiencies.

0007] In one aspect, the disclosed technology provides a compound comprising, onsisting of, or consisting essentially of a water soluble CTA-acid. In an embodiment, the water soluble CTA-acid can be in the form of a water soluble CTA-acid alt.

0008] In an embodiment, the water soluble CTA-acid can be a thiocarbonate ompound of any one of formulas I, Π, III or IV:

wherein

each of R ¹ and R ² is an alkyl group of four carbons or less or H,

so long as the sum of the number of carbon atoms present for all R ¹ , and R ² in formula I together is less than four; or formula II

wherein

each of R ¹ and R ² is as defined abov and R ³ is an alkyl group of four carbons or less, or H,

so long as the sum of the number of carbon atoms present for all R ¹ , R ² and R ³ in formula II together is less than four; or formula ΠΙ

wherein

each of R ⁴ and/or R ⁵ substituents, independently, comprise an alkyl group having from 1 to 4 carbon atoms, or H;

j is 1 or 2, with the proviso that when j is 1, T is— and when j is 2, T

is a divalent radical having a nitrogen atom directly connected to each carbon atom of the two thiocarbonyl groups present;

R ⁶ and R ⁷ , independently, are the same or different, and are H or a linear or branched alkyl having from 1 to 4 carbon atoms;

so long as the sum of the number of carbon atoms present for all R substituents in formula ΙΠ together is less than four; or formula IV

wherein

each of R ⁴ , and R ⁵ are as defined above

R ¹³ is optionally substituted, and is a linear or branched alkyl having from 1 to 4 carbon atoms; and

a is 1 to 4;

so long as the sum of the number of carbon atoms present for all R substituents in formula IV together is less than four.

0009] In another embodiment, the water soluble CTA-acid can be in the form of water soluble CTA-acid salt, and the CTA-acid portion of the water soluble CTA-cid salt can be a thiocarbonate compound having any of formulas I, Π, ΠΙ, or IV:

wherein

R ¹ and R ² , independently, are selected from a linear or branched alkyl having from 1 to 6 carbon atoms, a substituted alkyl having from 1 to 6 carbon atoms, substituted and unsubstituted aryl, R ¹ and R ² can form a substituted or unsub- stituted cyclic ring having from 5 to 12 total carbon atoms; wherein said sub- stituents, independently, are selected from an alkyl having from 1 to 6 carbon atoms, aryl, a halogen which can be the same or different, cyano, an ether having a total of from 2 to 20 carbon atoms, and a nitro group; or formula II

wherein

R ³ is selected from benzyl, a Ci through Cie alkyl, a substituted Ci to Cie alkyl, wherein said substituted group is selected from halogen, hydroxyl, alkoxy, a Ci to Cie hydroxyalkyl, aralkyl, cyanoalkyl, aminoalkyl, carboxylalkyl, car- boalkoxyalkyl, and mercaptoalkyl, and wherein R ¹ and R ² , independently, are as described above; or formula ΙΠ

wherein

j is 1 or 2, with the proviso that when j is 1, T is (~NR ⁶ R ⁷ ), and when j is 2, T is a divalent radical having a nitrogen atom directly connected to each carbon atom of the two thiocarbonyl groups; R ⁴ and R ⁵ , independently, are the same or different, are optionally substituted as defined for R ¹ and R ² , and are selected from a linear or branched alkyl having from 1 to 12 carbon atoms, aryl having from 6 to 18 carbon atoms, R ⁴ and R ⁵ can form a substituted or unsubstituted cyclic ring having from 3 to 12 carbon atoms, wherein said substituents, independently, are selected from an alkyl having from 1 to 6 carbon atoms, aryl, halogen, cyano, an ether having a total of from 2 to 20 carbon atoms, a nitro group, and combinations thereof; wherein R ⁶ and R ⁷ , independently, are the same or different, optionally substituted as defined for R ¹ and R ² , and are selected from hydrogen, a linear or branched alkyl having from 1 to 18 carbon atoms, aryl, aryl alkyl having from 6 to 18 carbon atoms, optionally saturated or unsaturated, arylalkyl having from 7 to 18 carbons, alkenealkyl having from 3 to 18 carbon atoms, polyalkylene glycol ether having from 3 to 200 carbon atoms, and amine, or R ⁶ and R ⁷ can form a cyclic ring with the nitrogen atom having a total of 4 to 12 carbon atoms; or formula IV

wherein

R ⁴ and R ⁵ are as defined above;

R ¹³ is optionally substituted, and is selected from linear or branched alkyl having from 1 to 12 carbon atoms, aryl optionally saturated or unsaturated, arylalkyl having from 7 to 18 carbon atoms, acyl, alkene, alkenealkyl having from 3 to 18 carbon atoms, an alkyl ene group, an alkoxyalkyl, polyalkylene glycol, polyalkylene glycol monoalkyl ether having from 3 to 200 carbon atoms, and 2- trifluoroethyl; wherein when R ¹³ is optionally substituted the substituent is selected from alkyl having from 1 to 6 carbon atoms, aryl, halogen, a cyano group, an amino group, an alkene group, an alkoxycarbonyl group, an ar- yloxycarbonyl group, a carboxy group, an acyloxy group, a carbamoyl group, an alkylcarbonyl group, an alkylarylcarbonyl group, an arylcarbonyl group, an aryl alkylcarbonyl group, a phthalimido group, a maleimido group, a suc- cinimido group, amidino group, guanidimo group, allyl group, epoxy group, alkoxy group, an alkali metal salt, a cationic substituent, a hydroxyl group, an ether having a total of from 2 to 20 carbon atoms, nitro, sulfur, phosphorous, a carboalkoxy group, and combinations thereof; and

a" is 1 to 4. [0010] In an embodiment, the water soluble CTA-acid in the form of a water solble CTA-acid salt can exclude the CTA-acid portion represented by formula Π. 0011] In embodiment of the compound, the water soluble CTA-acid can be in the orm of a water soluble CTA-acid salt, and the CTA-acid portion can comprise, con- ists of, or consist essentially of 2-methyl-2-[(dodecylsulfanylthiocarbonyl)sulfa- yl]propionic acid. In another embodiment, the water soluble CTA-acid salt can exlude 2-methyl-2-[(dodecylsulfanylthiocarbonyl)sulfanyl]propionic acid.

0012] In embodiments, the salts of the compounds can be derived from alkali or lkali earth metal hydroxides; alkali earth carbonates; mono-, di-, and/or tri-alkyl- ubstituted amines; and combinations thereof.

0013] Another aspect of the disclosed technology includes a polymer comprising, onsisting of, or consisting essentially of (A) at least one water soluble CTA-acid or CTA-acid salt as described herein, or combinations thereof, and (B) monomer units erived from at least one water soluble monomer. In an embodiment, the polymer an also optionally include (C) monomer units derived from at least one water insolble vinyl monomer. In an embodiment of the polymer, the water soluble CTA-acid an include a water soluble CTA-acid salt having a CTA-acid portion represented by ormula Π, and in a particular embodiment, the CTA-acid salt can be the sodium salt f 2-methyl-2-[(dodecylsulfanylthiocarbonyl)sulfanyl]propionic acid.

0014] In an embodiment, the water soluble monomers can comprise, consist of, r consist essentially of AMPS ^® , acrylic acid, methacrylic acid, itaconic acid, maleic cid, fumaric acid, citraconic acid, mesaconic acid, (alkyl) acryl amide, and derivaves or salts thereof, or any combination thereof. Water insoluble monomers can omprise, consist of, or consist essentially of any polymerizable monomer that in- ludes an alkyl group containing 1-18 carbon atoms consisting of a simple ester, a inyl ester, a mono-allyl ether, styrene, derivatives thereof, or any combinationhereof.

0015] In an embodiment, the polymer can comprise, consist of, or consist essenally of about 0.1 to about 50 weight percent units derived from (A) and from about 0 to about 99.9 percent by weight of the combination of (B) and optional (C). [0016] A further aspect of the disclosed technology includes a process of producng a water soluble polymer. The process can comprise, consist of, or consist essenally of the steps of 1) combining in an aqueous solution a water soluble ethylenically ubstituted monomer, a CTA-Acid or CTA-acid salt as described herein, or combi- ations thereof, and a free radical initiator, and 2) free radically polymerizing the water soluble monomers or allowing the water soluble monomers to free radically olymerize. In an embodiment, the process can include producing a macro-CTA- Acid or macro-CTA-Acid salt, and the process can further include adding a water- nsoluble monomer to form an oil-in-water emulsion, and further free radically poly- merizing the water-insoluble monomer with the macro-CTA-Acid or macro-CTA- Acid salt. In an embodiment of the process, the water soluble CTA-acid can include water soluble CTA-acid salt having a CTA-acid portion represented by formula II, nd in a particular embodiment, the CTA-acid salt can be the sodium salt of 2-methyl- -[(dodecylsulfanylthiocarbonyl)sulfanyl]propionic acid.

0017] Another aspect of the disclosed technology contemplates the use of a CTA- Acid, CTA-acid salt or mixture thereof as a chain transfer agent. In an embodiment, he water soluble CTA-acid can be used as a chain transfer agent in the form of a water soluble CTA-acid salt having a CTA-acid portion represented by formula Π, nd in a particular embodiment, the CTA-acid salt can be the sodium salt of 2-methyl- -[(dodecylsulfanylthiocarbonyl)sulfanyl]propionic acid.

0018] These and other aspects will be described below by way of non-limiting lustration.

DETAILED DESCRIPTION OF THE INVENTION

0019] An aspect of the present technology is directed to a compound comprising, onsisting essentially of, or consisting of a water soluble chain transfer agent, also eferred to herein as a water soluble CTA-acid. In some embodiments, the CTA-acid s inherently water soluble and in other embodiments, the CTA-acid is prepared into water soluble salt, also referred to as a CTA-acid salt. As used herein, the term water soluble CTA-acid, or even simply CTA-acid, includes water soluble CTA-acid alts.

0020] As used herein, water soluble means sufficiently miscible to form a S wt% olution. CTA-Acids

0021] Many CTA-acids are known. There are, for example, the thiocarbonates, or example, polythiocarbonates such as dithiocarbonate or trithiocarbonate comounds and derivatives thereof. By the term "thiocarbonate", it is meant a compound aving at least one segment having the formula:

wherein X comprises OR (also referred to herein as "xanthates"), SR (also referred o herein as "carbonates"), or NR2 (also referred to herein as "carbamates"), for exmple with R being various hydrocarbon, heteroatom and/or hydrogen containing tructures or the like preferably as illustrated hereinbelow, but not limited thereto. 0022] Suitable trithiocarbonate compounds for use in the present invention, inlude, but are not limited to, those disclosed in U.S. Pat. No. 6,596,899 to Lai, herein ully incorporated by reference. In one embodiment, di-acid trithiocarbonate comounds have the following general formula:

wherein, in one embodiment, R ¹ and R ² , independently, are the same or different, and re hydrogen ("H"), or linear or branched alkyls having from 1 to about 6 carbon toms, or from 1 to 4 carbon atoms, or a Ci to about Ce alkyl having one or more ubstituents, or one or more aryls or a substituted aryl group having 1 to 6 substituents n the aryl ring, where the one or more substituents, independently, comprise an alkyl aving from 1 to 6 carbon atoms; or an aryl; or a halogen such as fluorine or chlorine; r a cyano group; or an ether having a total of from 2 to about 20 carbon atoms such s methoxy, or hexanoxy; or a nitro; or combinations thereof. Examples of such compounds include s,s'-bis-2-methyl-2-propanoic acid-trithiocarbonate and s,s'-bis- 2-phenyl-2-propanoic acid)-trithiocarbonate. R ¹ and R ² can also form or be a part of cyclic ring having from 5 to about 12 total carbon atoms. R ¹ and R ² are preferably, ndependently, methyl or phenyl groups. As will be the case for all CTA-acids dis- losed herein, the compound represented by the formula will be water-soluble, or at east partially water-soluble depending on the number of carbon atoms in the substit- ents, and in the case of the formula above specifically, R ¹ and R ² . In a water-soluble mbodiment, of the above di-acid thiocarbonate, the sum of the number of carbon toms present for all R ¹ and R ² together can be less than 4, or less than 3, with any emainder substituents being H. In such a case, R ¹ and R ² are preferably, indeendently, methyl or H groups.

0023] The abbreviated reaction formula for one method for the preparation of ,s'-bis-(a, a'-disubstituted-a"-acetic acid)-trithiocarbonates is generally written as ollows:

0024] The process utilized to form s,s'-bis-(a, a'-disubstituted-a"-acetic acid)- ri thiocarbonate compounds is generally a multi-step process and includes combining he carbon disulfide and a base whereby an intermediate trithio structure is formed. A ketone can serve as solvent for the carbon disul fide/base reaction and thus can be dded in the first step of the reaction. In the second step of the reaction, the haloform, r haloform and ketone, or an a-trihalomethyl-a-alkanol are added to the trithio inermediate mixture and reacted in the presence of additional base. The formed reacon product, is subsequently acidified, thus completing the reaction and forming the bove described s,s'-bis-(a,a'-disubstituted-a"-acetic acid)-tri thiocarbonate comound. [0025] Another aspect of present invention utilizes mono-acid trithiocarbonate ompounds having the following formula:

wherein R ³ comprises H, a benzyl group, C ₁ - C ₁₈ or C ₁ - C ₄ alkyl, or substituted alkyl uch as halogen, hydroxyl, or alkoxy, C ₁ - C ₁₈ hydroxyalkyl, aralkyl, hydroxyalkyl, cy- noalkyl, aminoalkyl, carboxylalkyl, carboalkoxyalkyl or mercaptoalkyl, and R ¹ and R ² re defined hereinabove. The resulting compound is an s-substituted- s'-(a,a'- disubsti- uted-a"-acetic acid)-trithiocarbonate, such as, for example, 2-methyl-2-[(dodecyl- ulfanylthiocarbonyl)sulfanyl]propionic acid. Here again, the compound will be water- oluble, or at least partially water-soluble depending on the number of carbon atoms in the ubstituents, in this case R ¹ , R ² and R ³ . In an embodiment, of the mono-acid thiocarbonate, he sum of the number of carbon atoms present for all R ¹ , R ² and R ³ together can be less han 4, or less than 3, with any remainder being H. In a water-soluble embodiment, R ¹ , R ² nd R ³ are preferably, independently, methyl or H groups.

0026] Dithiocarbonate compounds which are utilized in some embodiments of he present invention are disclosed in U.S. application Ser. No. 10/278,335 filed Oct. 3, 2002 and U.S. application Ser. No. 10/681,679 filed Oct. 8, 2003, herein fully ncorporated by reference. In one embodiment the dithiocarbamate compounds have he following formula:

wherein j is 1 or 2, with the proviso that when and when j is

, T is a divalent radical having a nitrogen atom directly connected to each carbon tom of the two thiocarbonyl groups present;

wherein R ⁴ and R ⁵ , independently, are the same or different, are H or optionally sub- tituted, and are linear or branched alkyls having from 1 to about 4 carbon atoms, or to about 6 or about 12 carbon atoms; or an aryl group having from 6 to about 18 arbon atoms, optionally containing heteroatoms;

wherein the R ⁴ and/or R ⁵ substituents, independently, comprise an alkyl having from to 4 or 6 carbon atoms; an aryl group; a halogen; a cyano group; an ether having a otal of from 2 to about 20 carbon atoms; a nitro; or combinations thereof. R ⁴ and R ⁵ an also form or be a part of a substituted or unsub stituted cyclic ring having from 3 o about 12 total carbon atoms wherein the substituents are described above. R ⁴ and R ⁵ , in an embodiment, are, independently, methyl, H, or phenyl groups;

wherein R ⁶ and R ⁷ , independently, are the same or different, optionally are substi- uted, optionally contains heteroatoms; and are H; a linear or branched alkyl having rom 1 to 4 carbon atoms, or from 1 to about 18 carbon atoms, an aryl group having rom about 6 to about 18 carbon atoms optionally saturated or unsaturated; an arl alkyl having from about 7 to about 18 carbon atoms; an alkenealkyl having from 3 o about 18 carbon atoms; or derived from a polyalkylene glycol ether having from 3 o about 200 carbon atoms. R ⁶ and R ⁷ can also be derived from amines such as, but ot limited to, piperazine, morpholine, pyrrolidine, piperidine, 4-alkylamino-2,2,6,6- etramethyl piperidine, l-alkylamioalkyl-3,3,5,5-tetramethyl -2 piperazinone, hexa- methyleneimine, phenothiazine, iminodibenzyl, phenoxazine, N,N'-diphenyl-l,4- henylenediamine, dicyclohexylamine and derivatives thereof. R ⁶ and R ⁷ can also orm a substituted or unsubstituted cyclic ring, optionally containing heteroatoms, long with the nitrogen having a total of from 4 to about 12 carbon atoms, such as enzotriazole, tolyltriazole, imidazole, 2-oxazolidone, 4,4-dimethyloxazolidone and he like. The R ⁶ and R ⁷ substituents, independently, can be the same as described erein with respect to R ¹³ . R ⁶ and R ⁷ can be, in an embodiment, independently, a henyl group or an alkyl or substituted alkyl having from 1 to about 18 carbon atoms uch as a methyl group, or R ⁶ and R ⁷ , independently, can be hexamethylene. In an mbodiment, R ⁴ , R ⁵ , R ⁶ and R ⁷ are, independently, methyl or H groups. [0027] When j is 1, T of the above formula is and the dithiocarbamate

ompound is an S-(a,a'-disubstituted-a"-acetic acid) dithiocarbamate generally havng the following formula:

wherein R ⁴ , R ⁵ , R ⁶ , and R ⁷ are as defined hereinabove.

0028] When j is 2, the dithiocarbarbamate compound is a bis-S-(a,a'-disubsti- uted-a"-acetic acid) dithiocarbamate having the following formula:

wherein R ⁴ and R ⁵ are defined hereinabove; and

wherein T is a divalent bridging radical having a nitrogen atom directly connected to ach of the thiocarbonyl groups present.

0029] In one embodiment T is:

wherein R ⁸ and R ⁹ , independently, is the same or different, is optionally substituted, and s H, a linear or branched alkyl having from 1 to 4 carbon atoms, or 1 to about 18 carbon toms, an aryl group having from about 6 to about 18 carbon atoms, an aryl alkyl having rom 7 to about 18 carbon atoms, or an alkenealkyl having from 3 to about 18 carbon toms, wherein the substitutents can be the same as described herein for R ¹ and R ² ;

wherein R ¹⁰ is optionally substituted, and is non-existent, or an alkyl ene group having from to about 18 carbon atoms with about 1 to about 4 or 6 carbon atoms preferred, or derived rom a polyalkylene glycol ether having from 3 to about 200 carbon atoms, wherein the substituents can be the same as described herein for R and R or are heteroatoms such as xygen, nitrogen, sulfur or phosphorous; and

wherein R ¹¹ and R ¹² independently, is the same or different, and is optionally substiuted as described for R ¹ and R ² , and is an alkylene group having from 1 to about 4 arbon atoms, with R ¹¹ and R ¹² preferably having a collective total of 2 or 3 to 5 arbon atoms.

0030] In further embodiments, T is:

wherein n is 0 to about 18, with 0 or 1 to about 6 preferred;

wherein n is 0 to about 18, with 0 to about 6 preferred;

0031] Some specific non-limiting examples of T bridging radicals are:

0032] The S-(a,a'-disubstituted-a"-acetic acid) or bis-S-(a,a'-disubstituted-a"-ace- c acid) dithiocarbamates are generally a reaction product of a metal salt of a dithiocarba- mate, a haloform, and a ketone. A phase transfer catalyst, solvent, and a base such as odium hydroxide or potassium hydroxide can also be utilized to form the S-(oc,a'-disub- tituted-a"-acetic acid) or bis S-(a,a'-disubstituted-a"-acetic acid) dithiocarbamates. [0033] It is to be understood throughout the application formulas, reaction schemes, mechanisms, etc., and the specification that metals such as sodium or bases such as sodium ydroxide are referred to and the application of the present invention is not meant to be olely limited thereto. Other metals or bases such as, but not limited to, potassium and otassium hydroxide, respectively, or combinations thereof are contemplated by the dislosure of the present invention.

0034] Alkoxy dithiocarbonate compounds are utilized in some embodiments of he present invention and having the following general formula, which may be reerred to herein as a xanthate,

wherein R ⁴ and R ⁵ are as defined hereinabove;

wherein R ¹³ is optionally substituted, and can be a linear or branched alkyl aving from 1 to 4 carbon atoms, or 1 to about 12 carbon atoms; an aryl group, oponally saturated or unsaturated; an arylalkyl having from 7 to about 18 carbon atms; an acyl group; an alkenealkyl having from 3 to about 18 carbon atoms; an alkene roup; an alkyl en e group; an alkoxy alkyl; derived from a polyalkylene glycol; derived from a polyalkylene glycol monoalkyl ether having from 3 to 200 carbon atoms; erived from a polyalkylene glycol monoaryl ether having from 3 to 200 carbon atms; a polyfluoroalkyl such as 2-trifluoroethyl; a phosphorous containing alkyl; or a ubstituted or unsubstituted aryl ring containing heteroatoms. Alkyl and alkylene roups from 1 to 4 or 6 carbon atoms are preferred;

wherein the R ¹³ substituents comprise an alkyl having from 1 to 4 or 6 carbon toms; an aryl; a halogen such as fluorine or chlorine; a cyano group; an amino group; n alkene group; an alkoxycarbonyl group; an aryloxycarbonyl group; a carboxy roup; an acyloxy group; a carbamoyl group; an alkylcarbonyl group; an alkylaryl- arbonyl group; an arylcarbonyl group; an aryl alkylcarbonyl group; a phthalimido group; a maleimido group; a succinimido group; amidino group; guanidimo group; llyl group; epoxy group; alkoxy group; an alkali metal salt; a cationic substitutent uch as a quaternary ammonium salt; a hydroxyl group; an ether having a total of rom 2 to about 20 carbon atoms such as methoxy, or hexanoxy; a nitro; sulfur; phoshorous; a carboalkoxy group; a heterocyclic group containing one or more sulfur, xygen or nitrogen atoms, or combinations thereof; and wherein "a" is 1 to about 4, with 1 or 2 preferred.

0035] The compounds of the above formula are generally identified as O-alkyl- -(a,a'-disubstituted-a"-acetic acid) xanthates. The 0-alkyl-S-(a,a'-disubstituted- a"-acetic acid) xanthates are generated as the reaction product of an alkoxylate salt, arbon disulfide, a haloform, and a ketone. Alternatively, a metal salt of xanthate an be utilized in place of the alkoxylate salt and carbon disulfide.

0036] The general reaction mechanism for forming the 0-alkyl-S-(a,a'-disubsti- uted-a"-acetic acid) xanthates is as follows:

wherein R ⁴ , R ⁵ , and R ¹³ are defined herein.

alts

0037] The foregoing CTA-acids can be salted, either to impart water-solubility or or ease of use. The salts of the CTA-acid are not particularly limited. Salts can in- lude, for example, alkali or alkali earth metal hydroxides; alkali earth carbonates; mono-, di-, and/or tri- alkyl-substituted amines; and combinations thereof.

0038] In an embodiment, the alkali metal hydroxides can include, but not be limted to, for example, lithium hydroxide, sodium hydroxide, potassium hydroxide. In ome preferred embodiments the alkali metal hydroxide salt can comprise, consist ssentially of, or consist of sodium hydroxide. In an embodiment, the alkali metal ydroxide can exclude sodium hydroxide, and the resultant polymer can exclude soium salts. [0039] In an embodiment, the alkali earth metal hydroxides can include, but not e limited to, for example, magnesium hydroxide or calcium hydroxide. Similarly, lkali earth carbonates can include, but not be limited to, for example, magnesium arbonate or calcium carbonate.

0040] Mono, di, and/or tri alkyl substituted amines can include those having an lkyl substitute having from 1 to 12 carbon atoms, or 1 to 8 carbon atoms, or even from to 4 or 6 carbon atoms. The amine can also be an alkanol amine in which the alkyl ubstituent includes at least one OH group. Particular alkyl amines can comprise, conist essentially of, or consist of any one or more of tri ethanol amine ("TEA"), ethan- l amine, 2-(dimethylamino)ethanol, diethylamine, 2-(2-aminoethoxy)ethanol, 3- mino- 1 -propanol, N-(2-hydroxyethyl)ethylenediamine.

Polymer

0041] A water soluble form of the CTA-acid or a water soluble CTA-acid in its alt form (i.e., a CTA-acid salt) can be employed to prepare a polymer in an aqueous medium.

0042] The term aqueous medium, or aqueous solution, and the like, means a meium containing a majority of water, optionally along with other water miscible solents, such as, for example, alcohols and the like. Preferred water miscible solvents nclude ethyl alcohol, isopropyl alcohol, t-butyl alcohol. Other solvents that may be artially water miscible can include, for example, ethyl acetate, methyl acetate, butyl cetate, benzene, toluene, methyl ethyl ketone, and methylene choride. These solents also can be used in combination with minor amounts, such as less than 10 vol- me%, of hydrocarbon solvents such as hexane, cyclohexane, mineral spirits, and the ke. A preferred water miscible solvent is isopropyl alcohol. In an embodiment, the queous medium consists of water.

0043] Such a polymer would comprise, consist essentially of, or consist of at least ne CTA-acid or CTA-acid salt (as the end-cap of the polymer chain), monomer units erived from at least one water soluble monomer, and optionally, monomer units derived rom at least one water insoluble vinyl monomer. In an embodiment, the CTA-acid pol- mer can be made up of about 0.1 to about 49.9 or 50 weight percent, or 0.1 to about 0 or 25 weight percent units derived from a CTA-acid, CTA-acid salt, or combinaon thereof, but generally from about 0.5 to about 5 weight percent, such as about 1 to about 3 weight percent units derived from a CTA-acid, CTA-acid salt, or combiation thereof; and from about 50 to about 99.8 or 99.9 weight percent, or about 75 r even about 90 or 95 to about 99.8 or 99.9 weight percent, or 97 to 99 weight percent f the combination of a water soluble monomer and optional water insoluble vinyl monomer. In an embodiment, the CTA-acid polymer can have about 0.1 to about 9.9 or 50 weight percent, or 0.1 to about 10 or 25 weight percent units derived from CTA-acid, CTA-acid salt, or combination thereof; from about 50 to about 99.9 perent by weight, or 75 or 90 to about 99.8 or 99.9 weight percent units derived from water soluble monomer, and optionally 0.1 to about 49.9 or 50 weight percent, or rom about 0.5 to about 24.9 weight percent, or from about 1 to about 9.9 weight ercent units derived from polymerizable water insoluble vinyl monomers.

Water Soluble Monomers

0044] Water soluble monomers that can be included in the polymer are not particuarly limited and can comprise, consist essentially of, or consist of any water soluble eth- lenically substituted monomer, such as, for example, 2-acrylamido-2-methylpropane sulonic acid ("AMPS™"), carboxylic acid monomers, (Ci - C12 alkyl) acrylamide, and derivatives or salts thereof, or any combination thereof.

0045] Water soluble carboxylic acid monomers can include, for example, ethyleni- ally unsaturated polymerizable carboxylic acid monomers. Suitable examples include what are often referred to as carboxylic monomers or acrylate monomers.

0046] Additional examples of suitable sulfonic acid monomers can include: Si- omer COPS®-I, commercially available from Rhodia, which is a 40% aqueous solution f sodium allyl ether sulfonate and sodium l-allyloxy-2-hydroxypropyl sulfonate, having molecular weight of about 218; vinyl benzene sulfonic acids, vinyl benzene sulfonates, lkyl vinyl benzene sulfonic acids, alkyl vinyl benzene sulfonates for example PINOMAR® NaSS, commercially available from Tosoh, which is a sodium p-styrene ulfonate having a molecular weight of about 206; 2-sulfoethylmetahcrylate; alkylvinyl ulfonic acids, alkyl vinyl sulfonates for example sodium vinyl sulfonate (SVS); sodium llyl sulfonate (SAS); sodium methally sulfonate (SMAS); dialkylaminoalkyl(meth)acry- ate; alkyl or hydrogen halide salts of aminoalkyl(meth)acrylate; hydroxy al- yl(meth)acrylate; or any combination thereof. [0047] In one embodiment, the unsaturated carboxylic monomers can have the ollowing general formulae:

wherein X is H; a metal ion such as Li, Na, K, or Ca; an amino group such as an lkylamino or dialkylamino group having from 1 to about 6 carbon atoms or an al- yl/hydrogen halide salt thereof; or hydroxy alkyl group having from 1 to 6 carbon toms.

0048] Specific water-soluble monomers or co-monomers for use in the preent technology include, but are not limited to, the following: acrylic acid, meth- crylic acid, 2-hydroxyethyl methacrylate, hydroxypropyl methacrylate (all isomers), ydroxybutyl methacrylate (all isomers), Ν,Ν-dimethylaminoethyl methacrylate, Ν,Ν-diethylaminoethyl methacrylate, 2-dimethylaminoethyl acrylate and its al- yl/hydrogen halide salts, 2-dimethylaminoethyl methacrylate and its alkyl/hydrogen alide salts, 2-hydroxyethyl acrylate, hydroxypropyl acrylate (all isomers), hydroxyutyl acrylate (all isomers), polyethylene glycol monoacrylate, polyethylene glycol monomethacrylate, polypropylene glycol monoacrylate, polypropylene glycol mono- methacrylate, N,N-diethylaminoethyl acrylate, maleic acid, fumaric acid, itaconic cid, crotonic acid, oleic acid, cinnamic acid, styrene sulfonic acid, and 2- crylamido-2-methylpropane sulfonic acid (AMPS). Some preferred monomers are AMPS™, acrylic acid, methacrylic acid, and acrylamide.

0049] In some embodiments the water soluble monomers are essentially free of ny acrylate monomers. In some embodiments the water soluble monomers are free of ny acrylate monomers. In some embodiments the polymers described herein are essenally free of any acrylate monomers. In some embodiments the polymers described herein re free of any acrylate monomers.

0050] In other embodiments the water soluble monomers can include acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, citraconic acid, mesaconic acid. 0051] In some embodiments the water soluble monomers can include one or more ompounds having the structural formula:

nd when R ¹² is CH ₃ , R ¹³ is COOH and R ¹⁴ and R ¹⁵ are different and are either H or COOH. uitable examples include maleic acid, itaconic acid, fumaric acid, citraconic acid and mesaconic acid, oleic acid, cinnamic acid or salts thereof. Unsaturated polymerizable monomers containing sulfonic acid or a salts thereof can also be included.

0052] In some embodiments the water soluble monomers can include: (iii) one or more (C1-C4 alkyl or dialkyl) amide monomers. In such embodiments the water soluble monomers may include one or more acrylamide monomers, which may also be described s ethylenically unsaturated amido functional monomers. Suitable examples include crylamide, methyl acrylamide, methyl methacrylamide, N-alkylmethacrylamide, N,N-di- lkylmethacrylamide, N-alkylacrylamide, N,N-dialkylacrylamide, and any combination hereof.

0053] In some embodiments the water soluble monomers can include Ν,Ν' -dimehyl acrylamide, t-butylacrylamide, t-octylacrylamide, or a combination thereof.

Optional Other Monomers

0054] In an embodiment other monomers, other than the water-soluble mono- mers described above, are optionally polymerized with the water soluble monomers uring a polymerization reaction. Examples of monomers include, but are not limited o, polymerizable water insoluble vinyl monomers, such as any polymerizable monmer that includes an alkyl group containing 1-18 carbon atoms consisting of a simle ester, a vinyl ester, a mono-allyl ether, derivatives thereof, or any combination hereof. Some examples of other monomers include vinyl acetate; styrene; diene monomers having a total of from 4 to 12 carbon atoms with examples including, but ot limited to, 1,3 -butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-l-3-butadiene, -methyl-l,3-pentadiene, 2,3-dimethyl-l,3-pentadiene, 2-phenyl- 1,3 -butadiene, and ,5-diethyl-l,3-octadiene; a-methyl styrene; and C1-C12 alkyl styrenes with substitute roups either on the chain or on the ring or both.

Polymerization Process [0055] A water soluble CTA-acid or a CTA-acid salt, can be employed to polymerize the above monomers in an aqueous medium by a living polymerization proess as described hereinbelow to form a CTA-acid polymer.

0056] A living polymerization is a chain polymerization which proceeds in the bsence of termination and chain transfer. The following experimental criteria can be tilized to diagnose a living polymerization.

1. Polymerization proceeds until all monomer has been consumed. Further addition of monomer results in continued polymerization.

2. The number average molecular weight, M _n (or X _n , the number average de- gree of polymerization), is a linear function of conversion.

3. The number of polymer molecules (and active centres) is constant and independent of conversion.

4. The molecular weight can be controlled by the stoichiometry of the reaction.

5. Narrow molecular weight distribution polymers are produced.

6. Chain-end functionalized polymers can be prepared in quantitative yields. 0057] Besides those mentioned above, other criteria can also help to determine he living character of polymerization. For radical living polymerization, one is the bility of the polymer isolated from the first step of polymerization to be used as a macroinitiator for the second step of a polymerization in which block copolymers or rafted polymers are ultimately formed. To confirm the formation of block copolymers, measurements of molecular weights and a determination of the structure of the locks are employed. For structure measurements, the examination of NMR or IR ignals for the segments where individual blocks are linked together and a determiation of the end groups are both very important. In radical polymerization, only ome of the criteria for living polymerizations are actually fulfilled. Due to their abil¬ty to undergo further polymerization, these types of polymers can also be called 'rective polymers'. A more detailed description of living polymerization can be found n "Living Free-Radical Block Copolymerization Using Thio-Inifertors", by Anton ebenik, Progress in Polymer Science, vol. 23, p. 876, 1998. [0058] The living polymerization processes can be used to produce polymers of arrow molecular weight distribution containing one or more monomers sequences whose length and composition are controlled by the stoichiometery of the reaction nd degree of conversion. Homopolymers, random copolymers or block polymers can e produced with a high degree of control and with low polydispersity. Low polydis- ersity polymers are those with polydispersities that are significantly less than those roduced by conventional free radical polymerization. In conventional free radical olymerization, polydispersities (polydispersity is defined as the ratio of the weight verage to the number average molecular weight M _w /M _n ) of the polymers formed are ypically greater than 2.0. Polydispersities obtained by utilizing water soluble CTA- cid or CTA-acid salt compounds and derivatives thereof as described herein can be .75 or 1.5, or less, often 1.3 or less, and, with appropriate choice of the chain transfer gent and the reaction conditions, can be 1.2S or less.

0059] When the water soluble CTA-acids and CTA-acid salts are utilized only as hain-transfer agents, the polymerization can be initiated with other initiators at ower temperature while yielding polymers with similarly controlled fashion.

0060] Free radical polymerizations utilizing the water soluble CTA-acids and

CTA-acid salts as both initiators and chain transfer agents generally form telechelic olymers. When an initiator other than the water soluble CTA-acids and CTA-acid alts is also utilized, a polymer having a single functional end group is formed in roportion to the amount of said other initiator to the water soluble CTA-acids or

CTA-acid salts utilized.

0061] The free radical living polymerization process can be applied to any monmers or monomer combinations which can be free-radically polymerized.

0062] In order to initiate the polymerization process, it is often desirable to utize an initiator as a source for initiating free radicals. Generally, the source of inititing radicals can be any suitable method of generating free radicals such as the thermally induced homolytic scission of a suitable compound(s) (thermal initiators such s peroxides, peroxyesters, or azo compounds), the spontaneous generation from monomer, redox initiating systems, photochemical initiating systems or high energy adiation such as electron beam, X- or gamma-radiation. The initiating system is choen such that under the reaction conditions there is no substantial adverse interaction of the initiator or the initiating radicals with the transfer agent under the conditions f the experiment. The initiator should also have the requisite solubility in the reacon medium or monomer mixture.

0063] Thermal initiators are chosen to have an appropriate half-life at the tem- erature of polymerization. The initiators can include one or more of the following ompounds: 2,2'-azobis(isobutyronitrile)(AlBN), 2,2'-azobis(2-cyano-2-butane), dimethyl 2,2'-azobisdimethylisobutyrate, 4,4'-azobis(4-cyanopentanoic acid), 1,1 '-azo- is(cyclohexanecarbanitrile), 2-(t-butylazo)-2-cyanopropane, 2,2'-azobis[2-methyl- N-(l,l)-bis(hydoxymethyl)-2-hydroxyethyl]propionamide, 2,2'-azobis[2-methyl-N- ydroxyethyl)]-propionamide, 2,2'-azobis(N,N'-dimethyleneisobutyramidine)dihy- rochloride, 2,2'-azobis(2-amidinopropane)dihydrochloride, 2,2'-azobis(N,N'-di- methyleneisobutyramine), 2,2'-azobis(2-methyl-N-[l,l-bis(hydroxymethyl)-2-hy- roxyethyl]propionamide), 2,2'-azobis(2-methyl N-[ 1 , 1 -bis(hydroxyme- hyl)ethyl]propionamide), 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)propionamide], ,2'-azobis(isobutyramide)dehydrate, 2,2'-azobis(2,2,4-trimethylpentane), 2,2'-azo- is(2-methylpropane), t-butyl peroxyacetate, t-butylperoxy-2-ethylhexanoate, t-butyl eroxybenzoate, t-butyl peroxyoctoate, t-butylperoxyneodecanoate, t-butylperoxy sobutyrate, t-amyl peroxypivalate, t-butyl peroxypivalate, di-isopropyl peroxydicar- onate, dicyclohexyl peroxydicarbonate, dicumyl peroxide, dibenzoyl peroxide, di- auroylperoxide, potassium peroxydi sulfate, ammonium peroxydisulfate, di-t-butyl yponitrite, and dicumyl hyponitrite.

0064] Photochemical initiator systems are chosen to have the requisite solubility n the reaction medium or monomer mixture and have an appropriate quantum yield or radical production under the conditions of the polymerization. Examples include enzoin derivatives, benzophenone, acyl phosphine oxides, and photo-redox systems roduction under the conditions of the polymerization. These initiating systems can nclude, but are not limited to, combinations of the following oxidants, potassium eroxydi suffate, hydrogen peroxide, t-butyl hydroperoxide and reductants, iron (+2), tanium (+3), potassium thiosulfite, and potassium bisulfite.

0065] Other suitable initiating systems are known to those of ordinary skill in the rt, and are described in recent texts. See, for example, Moad and Solomon "The Chemistry of Free Radical Polymerization", Pergamon, London. 1995. pp 53-95. [0066] The preferred initiators of the present technology are 2,2'-azobis[2-mthyl- N(2-hydroxyethyl)propionamide. The amount of initiators utilized in the polymeriation process can vary widely as generally from about 0.001 percent to about 99 ercent, and desirably from about 0.01 percent to about 50 or 75 percent based on the otal moles of CTA-acid or CTA-acid salt utilized. Preferably small amounts are utized, such as from about 0.1 percent to about 5, 10, 15, 20, or 25 mole percent based n the total moles of CTA-acid or CTA-acid salt. In order to form polymers which re predominately telechelic, initiators other than the thiocarbonate compounds are tilized in lesser amounts, such as from about 0.001 percent to about 5 percent, de- irably from about 0.01 percent to about 4.5 percent, and preferably from about 0.1 ercent to about 3 percent based on the molar equivalent to the total moles of CTA- cid or CTA-acid salt utilized.

0067] In order to form CTA-acid polymers having monomer repeat units therein, predetermined amount of CTA-acid or CTA-acid salt, or combination thereof, can e added to a suitable reaction vessel along with a predetermined amount of monomers), optional solvent, and optionally initiator. The amount of CTA-acid or CTA- cid salt utilized depends on the desired molecular weight of the polymer to be ormed and can be calculated as known to one of ordinary skill in the art. A formula or calculating the amount of CTA-acid or CTA-acid salt (CTA) is as follows: /

0068] The resulting compound can be a macro-CTA-acid monomer, or a polymer r copolymer. The resulting compounds are either telechelic with identical functional roups at the ends of the chain, or a compound having a single functional end group nd also an initiator terminated chain (formed by using a conventional initiator such s A1BN). As stated above, the ratios between the resulting polymers can be conrolled to give desired results and generally depends on the amount of initiator utized. The number of repeat groups from all sources, i.e., water soluble, optionally water insoluble and other monomers, or a combination thereof incorporated into each CTA-acid polymer is generally from about 1 to about 400, desirably from about 1 to bout 200, and preferably from about 2 to about 80. Inasmuch as one or more water oluble monomers and optionally one more water insoluble monomers or other monomers which are generally neither hydrophilic or hydrophobic can be utilized, it s to be understood that repeat groups of the polymers or copolymers of the present echnology can be the same or different, respectively. That is, random copolymers, erpolymers, etc., can be formed within either of the repeat groups noted, as well as lock copolymers which can be formed by initially adding one monomer and then ubsequently adding a different monomer (e.g., an internal block copolymer).

0069] The reaction conditions are chosen so that the temperature utilized will enerate a radical in a controlled fashion, wherein the temperature is generally from bout room temperature to about 200 °C. The reaction can be run at temperatures ower than room temperature, but it is impractical to do so. The temperature often epends on the initiator chosen for the reaction, for example, when A1BN is utilized, he temperature generally is from about 40 °C. to about 80 °C, when azodicyanodi- aleric acid is utilized, the temperature generally is from about 50 °C. to about 90 C, when di-t-butylperoxide is utilized, the temperature generally is from about 110 C. to about 160 °C, when a thiocarbonate is utilized, the temperature is generally rom about 80 °C. to about 200 °C.

0070] The polymerization process of this invention can be carried out in emulion, solution or suspension, in either a batch, semi-batch, continuous, or feed mode. n the case of emulsion or suspension polymerization, the medium will often be pre- ominately water and conventional stabilizers, dispersants and other additives can be resent. For solution polymerization, the reaction medium can be chosen from a wide ange of media to suit the monomer(s) being used.

0071] Examples of polymerization mechanisms incorporating water soluble monomers into CTA-acid polymers are as follows:

in c and c* are each 1 to about 200, and R ¹ , R ² , and R ³ are defined herein.

Example reaction mechanisms for adding monomers having a hydrophobic group, as well ter soluble monomers to a CTA-acid polymer can include preparing a macro-CTA-acid mer and adding the water insoluble monomer, as follows: wherein and y are defined herein.

[0073] The process disclosed herein can be carried out in emulsion, solution or suspension in either a batch, semi-batch, continuous, or feed mode. Otherwise-conventional procedures can be used to produce narrow polydispersity polymers. For lowest polydispersity polymers, the chain transfer agent is added before polymerization is commenced. For example, when carried out in batch mode in solution, the reactor is typically charged with chain transfer agent and monomer or medium plus monomer. The desired amount of initiator is then added to the mixture and the mixture is heated for a time which is dictated by the desired conversion and molecular weight.

[0074] Polymers with broad, yet controlled, polydispersity or with multimodal molecular weight distribution can be produced by controlled addition of the CTA- acid or CTA-acid salt over the course of the polymerization process.

[0075] In the case of emulsion or suspension polymerization the medium will of- ten be predominately water and the conventional stabilizers, dispersants and other additives can be present. For solution polymerization, the reaction medium can be chosen from a wide range of media to suit the monomer(s) being used.

[0076] As already stated, the use of feed polymerization conditions allows the use of chain transfer agents with lower transfer constants and allows the synthesis of block polymers that are not readily achieved using batch polymerization processes. If the polymerization is carried out as a feed system the reaction can be carried out as follows. The reactor is charged with the aqueous medium, the CTA-acid, CTA- acid salt or combination thereof, and optionally a portion of the monomer(s). The remaining monomer(s) is placed into a separate vessel. Initiator is dissolved or sus- pended in the reaction medium in another separate vessel. The medium in the reactor is heated and stirred while the monomer+aqueous medium and initiator+aqueous medium are introduced over time, for example by a syringe pump or other pumping device. The rate and duration of feed is determined largely by the quantity of solution the desired monomer/chain transfer agent/initiator ratio and the rate of the polymer- ization. When the feed is complete, heating can be continued for an additional period.

[0077] The water soluble CTA-acids can be employed to prepare polymers for potential applications in any formulation that might require a water soluble polymer of defined molecular weight and shape such as for example, paints and coatings, personal and home care, energy exploration and refinery applications, including but not limited to, water treatment applications, drilling fluids, paraffin inhibiting applications, cementing applications, completion applications, and fuel transportation appli- cations and for improving refinery and oilfield operational efficiencies.

[0078] In an embodiment, the water soluble CTA-acids can be employed to prepare improved polymers for use in a method of chelating ions of hardness (e.g., chelating or sequestering metal ions and the like) from a solution.

[0079] Typical household and I&I products tbat may contain polymers of the in- vention, include, without being limited thereto, fabric care products, such as laundry detergents (powder, liquid, gel, and unit doses) and fabric softeners (liquids or sheets), ironing sprays, dry cleaning aids, antiwrinkle sprays, stain and spot removers and the like; hard surface cleaners for the kitchen and bathroom and utilities and appliances employed or located therein, such as toilet bowl gels, tub and shower cleaners, hard water deposit removers, floor and tile cleaners, wall cleaners, floor and chrome fixture polishes, alkali-strippable vinyl floor cleaners, marble and ceramic cleaners, air freshener gels, liquid or powder cleaners for dishes (automatic and manual), and the like; disinfectant cleaners, such as toilet bowl and bidet cleaners, disinfectant hand soaps, room deodorizers, heavy duty hand soaps, cleaners and sanitizers, automotive cleaners and the like.

[0080] In an embodiment, the improved polymers or solutions thereof are employed in automatic dish detergents. Such dish detergents can be in different forms, such as, for example, liquid, powder, gels, tablets and unit dose pouches, bars, paste, hard or soft compressed monolayered tablet, hard or soft compressed multilayered tablet, single phase unidose detergent, multiphase unidosc comprising, for example, any combination of powder, granulate, liquid and gel phases. In another embodiment, the improved polymers can be used in laundry detergents both in liquid, powder, gels, tablets and unit dose pouches, bars, paste, hard or soft compressed monolayered tablet, hard or soft compressed multilayered tablet, single phase unidose detergent, mul- tiphase unidose comprising, for example, any combination of powder, granulate, liquid and gel phases. [00811 Exemplary water treatment applications include, for example, water purification processes for potable ft industrial uses, cooling water treatment, boiler water treatment, desalination (e.g., reverse osmosis, distillation), wastewater (e.g., municipal ft industrial) treatment, and the like. In one preferred embodiment, the improved polymers are used in water treatment applications as scale inhibitors and/or dispersants. [•082] Exemplary deposit control applications, both scale and suspended solid dispersion, as applied to water treatment mcluding fresh, saline, and process water, include, for example, cooling water treatment, boiler water treatment, thermal and reverse osmosis (RO) desalination, municipal and industrial wastewater, geotbermal exploration, oil and gas exploration and production, pulp and paper, sugar refining, as well as mining processes. Scale examples include calcium carbonate; calcium phosphates and phosphonates; calcium, barium, and strontium sulfates; magnesium hydroxide; calcium fluoride; calcium oxalates; silica; and silicates. In some cases, the improved polymers can be used as scale removing agents, theology modifiers in drilling operations as well as for shiny transport of solids suspended in water.

[0083] Exemplary personal care cleansers include but are not limited to shampoos (e.g., 2-in-l shampoos, conditioning shampoos, bodifying shampoos; moisturizing shampoos, temporary hair color shampoos, 3-in-l shampoos, anti-dandruff shampoos, hah ^* color maintenance shampoos, acid (neutralizing) shampoos, salicylic acid shampoos, medicated shampoos, baby shampoos, and the like), and skin and body cleansers (e.g., moisturizing body washes, antibacterial body washes; bath gels, shower gels, liquid hand soaps, bar soaps, body scrubs, bubble baths, facial scrubs, foot scrubs, and the like). Similarly, the improved polymer can be employed in pet and animal care applications. Exemplary pet and animal care cleansers include but are not limited to shampoos, medicated shampoos, conditioning shampoos (e.g., de- tangling, antistatic, grooming), and foaming shampoos.

[0084] The amount of each chemical component described is presented exclusive of any solvent or diluent oil, which may be customarily present in the commercial material, that is, on an active chemical basis, unless otherwise indicated. However, unless otherwise indicated, each chemical or composition referred to herein should be inter- preted as being a commercial grade material which may contain the isomers, by-products, derivatives, and other such materials which are normally understood to be present in the commercial grade.

[0085] It is known that some of the materials described above may interact in the final formulation, so that the components of the final formulation may be different from those that axe initially added. For instance, metal ions (of, e.g., a detergent) can migrate to other acidic or anionic sites of other molecules. The products formed thereby, including the products formed upon employing the composition of the present invention in its intended use, may not be susceptible of easy description. Nevertheless, all such modifications and reaction products are included within the scope of the present invention; the present invention encompasses the composition prepared by admixing the components described above.

[0086] The invention herein is useful for preparing RAFT polymers in an aqueous medium, which may be better understood with reference to the following examples.

[0087] EXAMPLES

[0088] Samples

[0089] The following general laboratory procedure was used:

1. ) 200g of water was added to a round bottom flask along with 9 drops of 50 wt.% NaOH in water.

2. ) 1.94g of CTA-acid was added and the mixture gently warmed until dissolved.

3.) pH was adjusted to 7.5

4. ) CTA-Na solution was poured into a 1L 3-necked flask along with 0.55g

Vaso-086 initiator (a 2^'-Azobis[2-methyl-N-(2-hydroxyethyl)propio- namide] available from WAKO Chemicals)

5. ) The solution of CTA-Na and initiator was heated to 90°C and 100 g of a 53 wt.% solution of acrylamide in water was added over 2 hours.

6. ) The mixture thickened over time and after addition of all the monomer, solution was held at 90°C for an additional 2 hrs. before being air cooled to room temperature. General Polymerization Illustration

[0090] A series of polymerizations was conducted using the general polymerization method listed above. In this series the amount of CTA-Na was varied to produce poly(acryiamide) polymers of different molecular weights to demonstrate the controllability of this process to produce defined and predictable molecular weight polymers. The data is shown below in Table 1.

[0091] The same general synthetic process as described above was used to poly- merize AMPS-Na monomer as well. Again the CTA-Na amount was varied to demonstrate (he controllability of this process to produce defined molecular weight polymers. Those results are shown below in Table 2.

[0092] Copolymers were produced using the above mentioned polymerization procedure with AMPS-Na (100 g) and acrylic acid (AA- lOOg). Random copolymers of AMPS-Na and AA were made by dissolving sodium acrylate in a solution of AMPS-Na (SO wt.% in water). The sodium salt of acrylic acid was used in this case in order to keep the pH of the polymerization mixture above 7. If the pH dips below this value, the CTA will revert back to its acid form and precipitate out of solution leading to uncontrolled polymerization.

[0093] Block copolymers were also produced using AMPS-Na and AA. They were also synthesized according to the general polymerization process listed above by building a poly(AMPS-Na) block first, then adding acrylic acid to build a second block, producing poly(AMPS-b-acrylic acid). The results are shown below in Table 3.

Table 3: C

[0094] Star polymers were also produced by first forming a homopolymer of either AMPS or acrylamide using the above mentioned process, followed by a cross- linking reaction involving a difunctional monomer such as Bis-acryiamido-2- methylpropane sulfonic acid (BAMPS) or N h l bi l d

Those results are listed below in Table 4.

[0095] In addition to neutralizing CTA-acid with NaOH to generate the water- soluble chain transfer agent, various amines were used instead of NaOH. These new CTA-"bases" were made using die same procedure shown above ("Formation of CTA-Acid Sait(s)") starting with CTA-acid. The stability of several amines was tested by dispersing CTA-acid in water at 1 wt.% CTA-acid, and then dissolution by adding the amine. The resulting solutions were left at room temperature for 48 hrs. at which point the solubility was checked again. The results are shown below in Table 5.

Table 5: Amine Saks of CTA-Acid in Water

[0096] Two of the CTA-amine salts (CTA-TEA and CTA-diethylamine) were chosen to make poly(acrylamide) and poly(AMPS) based on the previously described general polymerization process. Those results are shown below in Table 6.

Table 6: Poly(acrylamide) and Poly(AMPS) Using Amine Salt* of CI A- Add

Example 1

[0097] The calcium binding ability of the AMPS/AA block copolymers of samples 7 through 14 was tested against the comparative AMPS/AA random copolymers shown in table 7.

[0098] Calcium binding was determined by preparing lOOmL of a 1 wt% solution of the polymers in water, and adding the solutions to a burette. The polymer solution was then titrated against lOOmL of a standard 0.01M CaCb solution. A Ca selective electrode is used to measure the Ca ion signal present in solution (not bound to the polymer). Once the electrode measures 0.00 concentration, all of the Ca ions from the standard have been chelated to the polymer. From there, a calculation can then be performed to determine the amount of polymer needed to bind all of the Ca from the standard solution. The results of the calcium binding tests are shown in Table 8. Table 8: Calcium Binding

[0099] The data in Table 8 shows that the sample polymers prepared with the water soluble CTA-acid bound more calcium than the random copolymers not prepared with the water soluble CTA-acid

[00100] Each of the documents referred to above is incorporated herein by reference, including any prior applications, whether or not specifically listed above, from which priority is claimed. The mention of any document is not an admission that such docu- ment qualifies as prior art or constitutes the general knowledge of the skilled person in any jurisdiction. Except in the Examples, or where otherwise explicitly indicated, all numerical quantities in this description specifying amounts of materials, reaction conditions, molecular weights, number of carbon atoms, and the like, are to be understood as modified by the word "about.'' It IB to be understood that the upper and lower amount, range, and ratio limits set forth herein may be independently combined. Similarly, the ranges and amounts for each element of the invention can be used together with ranges or amounts for any of the other elements.

[00101] As used herein, the transitional term "comprising," which is synonymous with "including," "containing," or "characterized by," is inclusive or open-ended and does not exclude additional, un-recited elements or method steps. However, in each recitation of "comprising" herein, it is intended that the term also encompass, as alternative embodiments, the phrases "consisting essentially of" and "consisting of," where "consisting of excludes any element or step not specified and "consisting essentially of permits the inclusion of additional un-recited elements or steps that do not materially affect the essential or basic and novel characteristics of the composition or method under consideration.

[00102] While certain representative embodiments and details have been shown for the purpose of illustrating the subject invention, it will be apparent to those skilled in this art that various changes and modifications can be made therein without departing from the scope of the subject invention. In this regard, the scope of the invention is to be limited only by the following claims.