Amine neutralized sulfonated block copolymers and method for making same

• US 8,263,713 B2
• Filed: 10/13/2009
• Issued: 09/11/2012
• Est. Priority Date: 10/13/2009
• Status: Active Grant

• Current Assignee: Kraton Polymers US LLC (DL Holdings Co., Ltd.)
• Original Assignee: Kraton Polymers US LLC (DL Holdings Co., Ltd.)
• Inventors: Willis, Carl Lesley
• Primary Examiner(s): Choi, Ling
• Assistant Examiner(s): DOLLINGER, MICHAEL M
• Application Number:
  US12/578,401
• Publication Number:
  US 20110086982A1
• Time in Patent Office: 1,064 Days
• Field of Search: 525/333.5
• US Class Current: 525/333.5
• CPC Class Codes: B01D 71/26 Polyalkenes
• CPC Class Codes: B01D 71/28 Polymers of vinyl aromatic compounds
• CPC Class Codes: B01D 71/40 Polymers of unsaturated acids or derivatives thereof, e.g. salts, amides, imides, nitriles, anhydrides, esters
• CPC Class Codes: B01D 71/80 Block polymers
• CPC Class Codes: B01D 71/82 characterised by the presence of specified groups, e.g. introduced by chemical after-treatment
• CPC Class Codes: C08F 297/046 polymerising vinyl aromatic monomers and isoprene, optionally with other conjugated dienes
• CPC Class Codes: C08F 8/36 Sulfonation; Sulfation
• CPC Class Codes: H01M 8/1032 having sulfur, e.g. sulfonated-polyethersulfones [S-PES]
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

An Amine neutralized sulfonated block copolymer and a method for neutralizing a sulfonated block copolymer, the process including providing a solution comprising an organic solvent and the non-neutralized block copolymer in micellar form, and adding at least one amine to the solution.

Claims

1. A process for preparing a membrane comprising a sulfonated block copolymer, said process comprising:

providing a solution comprising an organic solvent and the non-neutralized block copolymer in micellar form, and

adding at least one amine to the solution, wherein the amine is a multi-functional amine having from two to four nitrogen functionalities, and comprises at least two nitrogen functionalities which are linked to one another via a linear, branched, or cyclic aliphatic bridging moiety, and subsequently forming said solution into a membrane comprising the sulfonated block copolymer,

wherein the sulfonated block copolymer prior to neutralization has at least one end block A and at least one interior block B wherein each A block contains essentially no sulfonic acid or sulfonate ester functional groups and each B block is a polymer block containing from about 10 to about 100 mol percent sulfonic acid or sulfonate ester functional groups based on the number of monomer units of the B block and which are not neutralized,

wherein each A block comprises one or more segments selected from polymerized (i) para-substituted styrene monomers, (ii) ethylene, (iii) alpha olefins of 3 to 18 carbon atoms, (iv) 1,3-cyclodiene monomers, (v) monomers of conjugated dienes having a vinyl content less than 35 mol percent prior to hydrogenation, (vi) acrylic esters, (vii) methacrylic esters, and (viii) mixtures thereof;

each B block comprises segments of one or more vinyl aromatic monomers selected from polymerized (i) unsubstituted styrene monomers, (ii) ortho-substituted styrene monomers, (iii) meta-substituted styrene monomers, (iv) alpha-methylstyrene, (v) 1,1-diphenylethylene, (vi) 1,2-diphenylethylene and (vii) mixtures thereof.

2. The process of claim 1 wherein from 80% or more of the sulfonic acid or sulfonate ester functional groups are neutralized.

3. The process of claim 1 wherein the amine is added in an amount of from about 0.8 to about 10 equivalents of amine base per 1 equivalent of sulfonic acid or sulfonate ester functional group of the non-neutralized block copolymer.

4. The process of claim 1 wherein the organic solvent is a non-halogenated aliphatic solvent.

5. The process of claim 1 wherein the organic solvent comprises at least a first and a second aliphatic solvent, and wherein the B block is substantially soluble in the first solvent and the A block is substantially soluble in the second solvent.

6. The process of claim 1 wherein the amine is a multi-functional amine having from two to three nitrogen functionalities.

7. The process of claim 1, wherein the sulfonated block copolymer has the general configuration A-B-A, A-B-A-B-A, (A-B-A)_nX, (A-B)_nX, A-D-B-D-A, A-B-D-B-A, (A-D-B)_nX, (A-B-D)_nX or mixtures thereof, where n is an integer from 2 to about 30, and X is a coupling agent residue and wherein each D block is a polymer block resistant to sulfonation and the plurality of A blocks, B blocks, or D blocks are the same or different.

8. The process of claim 7 wherein each D block is selected from the group consisting of (i) a polymerized or copolymerized conjugated diene selected from isoprene, 1,3-butadiene having a vinyl content prior to hydrogenation of between 20 and 80 mol percent, (ii) a polymerized acrylate monomer, (iii) a silicon polymer, (iv) polymerized isobutylene and (v) mixtures thereof, wherein any segments containing polymerized 1,3-butadiene or isoprene are subsequently hydrogenated.

25. The process of claim 1, wherein the multi-functional amine is selected from the group consisting of N,N-dimethylethylenediamine, N,N′

-dimethylethylenediamine, and 1,4-bis(3-aminopropyl)piperzine, or a mixture thereof.

26. The process of claim 1, wherein the multi-functional amine is selected from the group consisting of N,N-dimethylethylenediamine, N,N′

-dimethylethylenediamine, or a mixture thereof.

9. A membrane comprising a neutralized sulfonated block copolymer which is solid in water comprising at least two polymer end blocks A and at least one polymer interior block B, wherein

a. each A block contains essentially no sulfonic acid or sulfonate ester functional groups and each B block is a polymer block containing from about 10 to about 100 mol percent sulfonic acid or sulfonate ester functional groups based on the number of monomer units of the B block;

b. wherein each A block comprises one or more segments selected from polymerized (i) para-substituted styrene monomers, (ii) ethylene, (iii) alpha olefins of 3 to 18 carbon atoms, (iv) 1,3-cyclodiene monomers, (v) monomers of conjugated dienes having a vinyl content less than 35 mol percent prior to hydrogenation, (vi) acrylic esters, (vii) methacrylic esters, and (viii) mixtures thereof;

c. each B block comprises segments of one or more vinyl aromatic monomers selected from polymerized (i) unsubstituted styrene monomers, (ii) ortho-substituted styrene monomers, (iii) meta-substituted styrene monomers, (iv) alpha-methylstyrene, (v) 1,1-diphenylethylene, (vi) 1,2-diphenylethylene and (vii) mixtures thereof,

d. the sulfonated B blocks are neutralized with a multi-functional amine having from two to four nitrogen functionalities, wherein from 95% to 100% of the sulfonic acid or sulfonate ester functional groups in the B block are neutralized,

wherein the multi-functional amine comprises at least two nitrogen functionalities which are linked to one another via a linear, branched, or cyclic aliphatic bridging moiety.

10. The membrane of claim 9 wherein the multi-functional amine has 2 or 3 nitrogen functionalities.

11. The membrane of claim 9 wherein the bridging moiety has 2 to 4 carbons.

12. The membrane of claim 9, wherein the multifunctional amine has the general formulae:

R¹—

NH-A-NR²—

R³

wherein

A is a straight chain or branched alkylene moiety having from two to six carbon atoms;

R¹ is hydrogen or C₁-C₆-alkyl

R² is hydrogen or C₁-C₆-alkyl

R³ is C₁-C₆-alkyl;

or R² and R³ together with the nitrogen to which they are bonded form a 5 to 7 membered ring made up of 4 to 6 carbon atoms and optionally one or two additional nitrogen ring members wherein the additional nitrogen ring members are independently of one another substituted by hydrogen, C₁-C₆-alkyl or amino-substituted C₂-C₆-alkyl.

13. The membrane of claim 9, wherein the multi-functional amine is selected from the group consisting of N,N-dimethylethylenediamine, N,N′

-dimethylethylenediamine and 1,4-bis(3-aminopropyl)piperzine, or mixture thereof.

14. The membrane of claim 9 which meets one or both of the following provisions:

a. the neutralized block copolymer has a water uptake value which is equal to or less than the water uptake value of a corresponding, non-neutralized sulfonated block copolymer; and

/or

b. the neutralized block copolymer has a dry tensile modulus which is equal to or less than the dry tensile modulus of the corresponding, non-neutralized sulfonated block copolymer, the modulus measured according to ASTM D412.

15. The membrane of claim 9 having a water uptake value of less than 80% the water uptake value of a corresponding, non-neutralized sulfonated block copolymer.

16. The membrane of claim 9 having a water uptake value of less than 100% of its dry weight.

17. The membrane of claim 9 a water vapor transport rate of at least 15,000 g/m²/day/mil.

18. The membrane of claim 9, having a water transport rate of at least about 50% of the water transport rate of a corresponding non-neutralized block copolymer.

19. The membrane of claim 15, having a water transport rate of at least about 50% of the water transport rate of a corresponding non-neutralized block copolymer.

20. The membrane of claim 19, the neutralized block copolymer has a dry tensile modulus which is less than the dry tensile modulus of the corresponding, non-neutralized sulfonated block copolymer, the modulus measured according to ASTM D412.

21. The membrane of claim 9 which is in hydrated form.

22. The hydrated membrane of claim 21 which meets both of the following provisions:

a. the hydrated membrane has a water transport rate of at least about 50% of the water transport rate of a hydrated form of a corresponding, non-neutralized sulfonated block copolymer;

b. the hydrated membrane has a water uptake value of less than 80% the water uptake value of a corresponding, non-neutralized sulfonated block copolymer.

23. The membrane of claim 9 having a general configuration A-B-A, A-B-A-B-A, (A-B-A)_nX, (A-B)_nX, A-D-B-D-A, A-B-D-B-A, (A-D-B)_nX, (A-B-D)_nX or mixtures thereof, where n is an integer from 2 to about 30, and X is a coupling agent residue and wherein each D block is a polymer block resistant to sulfonation and the plurality of A blocks, B blocks, or D blocks are the same or different.

24. The membrane of claim 23 comprising one or more blocks D each block D being independently selected from the group consisting of (i) a polymerized or copolymerized conjugated diene selected from isoprene, 1,3-butadiene having a vinyl content prior to hydrogenation of between 20 and 80 mol percent, (ii) a polymerized acrylate monomer, (iii) a silicon polymer, (iv) polymerized isobutylene and (v) mixtures thereof, wherein any segments containing polymerized 1,3-butadiene or isoprene are subsequently hydrogenated.

27. The membrane of claim 9, wherein the multi-functional amine is selected from the group consisting of N,N-dimethylethylenediamine, N,N′

-dimethylethylenediamine, or a mixture thereof.