Process for synthesizing thiol terminated polymers

1. A process for removing one or more groups of the formula —S—(C═S)— from a starting polymer, which is in the form of a solution, dispersion, or a combination thereof, said process comprising:

contacting said starting polymer with one or more reagents to form at least (i) a derived polymer absent one or more groups of the formula —S—(C═S)—, and (ii) a byproduct, said one or more reagents selected from the group consisting of 2-(dimethylamino)ethylamine, 3-dimethylamino-1-propylamine, 4-amino-2,2,6,6-tetramethylpiperidine, and a reagent of the formula:

wherein

in said formula is a polymer moiety; and

separating said byproduct from said derived polymer.

2. The process of claim 1 wherein at least a stoichiometric amount of said reagent is contacted with said starting polymer.

3. The process of claim 1 wherein said starting polymer is a homopolymer, random, statistical, alternating or gradient copolymer, block polymer, star polymer, graft copolymer, dendritic or hyperbranched copolymer, microgel, or a combination thereof.

4. The process of claim 1 wherein said separating step comprises one or more of filtering, solvent extracting, precipitating, flocculating, adsorbing, or ion exchanging said byproduct from said derived polymer.

5. The process of claim 1 wherein said polymer moiety is derived from a styrenic polymer or an acrylic polymer.

6. The process of claim 5 wherein said styrenic polymer is a copolymer polymerized from a monomer mixture comprising divinylbenzene and styrene.

7. The process of claim 1 wherein in said contacting step said starting polymer is concurrently contacted with a reducing agent selected from the group consisting of a bisulfate salt, a thiosulfate salt, a tertiary phosphine, a tertiary phosphine salt, ascorbic acid, ascorbate salt and a combination thereof.

8. The process of claim 7 wherein said thiosulfate salt is Na 2 S 2 O 4 .

9. The process of claim 7 wherein said ascorbate salt is sodium ascorbate.

10. The process of claim 7 wherein said tertiary phosphine salt is tris(2-carboxyethyl)phosphine hydrochloride.

11. The process of claim 1 wherein said derived polymer is in the form of a solution, dispersion, precipitate or a combination thereof.

12. The process of claim 11 wherein said derived polymer has 1 to 6 thiol (—SH) groups.

13. The process of claim 12 wherein said starting polymer has a GPC number average molecular weight in the range of 500 to 100,000.

14. The process of claim 12 wherein said starting polymer has a polydispersity in the range of 1.05 to 3.0.

15. The process of claim 11 wherein said derived polymer has 2 to 6 thiol (—SH) groups.

16. The process of claim 15 further comprising contacting said derived polymer with a di-isocyanate to form polythiourethane.

17. The process of claim 1 wherein said starting polymer is polymerized from a monomer mixture comprising one or more vinyl monomers having the formula:

where L is selected from the group consisting of hydrogen, halogen, and substituted or unsubstituted C 1 -C 4 alkyl;

where M is selected from the group consisting of hydrogen, R′″, CO 2 H, CO 2 R′″, COR′″, CN, CONH 2 , PO(OR′″) 3 , CONHR′″, CONR′″ 2 , O 2 CR′″, OR′″, and halogen, wherein R′″ is independently selected from the group consisting of substituted or unsubstituted C 1 -C 22 alkyl, C 2 -C 22 substituted or unsubstituted alkenyl, C 2 -C 22 substituted or unsubstituted alkynyl, C 3 -C 22 substituted or unsubstituted cycloalkyl, C 6 -C 18 substituted or unsubstituted aryl, C 2 -C 18 substituted or unsubstituted heterocyclyl, C 7 -C 18 substituted or unsubstituted aralkyl, and C 7 -C 18 substituted or unsubstituted alkaryl; said substituents being independently selected from the group consisting of hydroxy, OR′″, CO 2 H, O 2 CR′″, CO 2 R′″, C 1 -C 22 alkyl, C 6 -C 18 aryl, ═O(oxo), C 6 -C 18 acyl, SO 3 H, sulfonate, cyano, C 3 -C 66 trialkoxysilyl, C 3 -C 66 trialkylsilyl, halo, C 2 -C 44 dialkylamino, amido and a combination thereof; and

a RAFT agent and a source of initiating radicals.

18. The process of claim 17 wherein said monomer mix further comprises maleic anhydride, N-alkylmaleimide, N-arylmaleimide, dialkyl fumarate, a cyclopolymerizable monomer, a ring-opening monomer or a combination thereof.

19. The process of claim 17 wherein said RAFT agent is of the formula:

or a combination thereof;

wherein R and R 1 are free radical leaving groups; and wherein,

R is selected from the group consisting of unsubstituted or substituted alkyl, unsubstituted or substituted alkenyl, unsubstituted or substituted C 2 to C 18 alkynyl, C 3 to C 22 substituted or unsubstituted cycloalkyl, C 4 to C 22 substituted or unsubstituted cycloalkenyl, C 6 to C 18 unsubstituted or substituted aryl, unsubstituted or substituted saturated heterocyclic ring, C 5 to C 18 unsubstituted or substituted unsaturated heterocyclic ring, C 4 to C 18 unsubstituted or substituted aromatic heterocyclic ring, C 1 to C 18 unsubstituted or substituted alkylthio group, and a first polymer chain having a number average degree of polymerization in the range of 5 to 1000;

wherein R″ is independently selected from the group consisting of substituted or unsubstituted C 1 -C 22 alkyl, C 2 -C 22 substituted or unsubstituted alkenyl, C 2 -C 22 substituted or unsubstituted alkynyl, C 3 -C 22 substituted or unsubstituted cycloalkyl, C 6 -C 18 substituted or unsubstituted aryl, C 2 -C 18 substituted or unsubstituted heterocyclyl, C 7 -C 18 substituted or unsubstituted aralkyl, and C 7 -C 18 substituted or unsubstituted alkaryl;

Z is selected from the group consisting of H, chloro, fluoro, unsubstituted or substituted alkyl, C 6 to C 18 unsubstituted or substituted aryl, unsubstituted or substituted heterocyclic ring, unsubstituted or substituted C 1 to C 18 alkylthio, SR, unsubstituted or substituted arylthio, unsubstituted or substituted C 1 to C 18 alkoxy, unsubstituted or substituted aryloxy, unsubstituted or substituted amino, unsubstituted or substituted C 1 to C 18 alkoxycarbonyl, unsubstituted or substituted aryloxycarbonyl, carboxy, unsubstituted or substituted C 1 to C 18 acyloxy, unsubstituted or substituted aroyloxy, unsubstituted or substituted carbamoyl, cyano, C 2 to C 18 dialkyl-phosphonato, diaryl-phosphonato, C 1 to C 18 dialkyl-phosphinato, diaryl-phosphinato, C 1 -C 22 trialkoxysilyl, C 1 -C 22 trialkylsilyl and a second polymer chain having a number average degree of polymerization in the range of 5 to 1000;

R 1 is an n-valent moiety derived from R;

Z 1 is an m-valent moiety derived from a species selected from the group consisting of unsubstituted or substituted alkyl, unsubstituted or substituted aryl and a third polymer chain having a number average degree of polymerization in the range of 5 to 1000 wherein the connecting moieties in said polymer chain are selected from the group consisting of C 1 to C 18 aliphatic carbon, aromatic carbon, oxygen, sulfur and a combination thereof;

n and m are integers that interpedently range from 1 to 6; and

wherein the substituents for the substituted groups for R, R 1 , R″, Z and Z 1 are independently selected from the group consisting of hydroxy, tertiary amino, halo, cyano, epoxy, carboxylic acid, alkoxy, alkyl having 1 to 32 carbon atoms, aryl, alkenyl having 2 to 32 carbon atoms, alkynyl having from 2 to 32 carbon atoms, saturated carbocyclic rings having 3 to 14 carbon atoms, unsaturated carbocyclic rings having 4 to 14 carbon atoms, aromatic carbocyclic rings having 6 to 14 carbon atoms, saturated heterocyclic rings having 3 to 14 carbon atoms, unsaturated heterocyclic rings having 3 to 14 carbon atoms and aromatic carbocyclic rings having 6 to 14 carbon atoms.