Uncrosslinked, high molecular weight, polyimide polymer containing a small amount of bulky diamine

Patent metadata

Field	Value
Publication number	US-9718033-B2
Application number	US-201615093549-A
Country	US
Kind code	B2
Filing date	Apr 7, 2016
Priority date	Dec 23, 2014
Publication date	Aug 1, 2017
Grant date	Aug 1, 2017

Abstract

One method as described herein relates to making a membrane comprising an uncrosslinked high molecular weight polyimide polymer with a small amount of bulky diamine. Also as described herein is a hollow fiber polymer membrane comprising an uncrosslinked high molecular weight polyimide polymer with a small amount of bulky diamine. The polyimide polymers include monomers comprising dianhydride monomers, diamino monomers without carboxylic acid functional groups, and optionally diamino monomers with carboxylic acid functional groups, wherein 2 to 10 mole % of the diamino monomers are bulky diamino compounds and the ratio of diamino monomers with carboxylic acid functional groups to diamino monomers without carboxylic acid functional groups is 0 to 2:3. These uncrosslinked high molecular weight polyimide polymers with a small amount of bulky diamine are useful in forming polymer membranes with high permeance and good selectivity that are useful for the separation of fluid mixtures.

First claim

What is claimed is:

1. A method of making a membrane comprising an uncrosslinked high molecular weight polyimide, the method comprising:
(a) preparing a polyimide from a reaction solution comprising monomers and at least one solvent, wherein the monomers comprise a dianhydride monomer, a diamino monomer without carboxylic acid functional groups, and optionally a diamino monomer with carboxylic acid functional groups, wherein 2 to 10 mole % of the total diamino monomers comprise a bulky diamino compound and the ratio of diamino monomers with carboxylic acid functional groups to diamino monomers without carboxylic acid functional groups is 0 to 2:3; and
(b) obtaining a membrane comprising the uncrosslinked polyimide with less than 30% by weight crosslinks.

2. The method of claim 1 , wherein the method does not comprise a step of treating the polyimide with a diol at esterification conditions.

3. The method of claim 1 , wherein the membrane obtained in step (b) comprises less than 10% by weight crosslinks.

4. The method of claim 1 , wherein the membrane obtained in step (b) comprises essentially no crosslinks.

5. The method of claim 1 , wherein the less than 30% by weight crosslinks are ester crosslinks.

6. The method of claim 1 , wherein the monomers comprise:
(a) a dianhydride monomer A of formula (I):

where X 1 and X 2 are independently halogenated alkyl, phenyl or halogen; and
R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 are independently H, alkyl, or halogen;
(b) a diamino monomer without carboxylic acid functional groups B;
(c) optionally a diamino monomer with carboxylic acid functional groups C; and
(d) a bulky diamino compound D different from diamino monomers B and C;

wherein 2 to 10 mole % of the total diamino monomers comprise the bulky diamino compound D.

7. The method of claim 6 , wherein A is 4,4′-(hexafluoroisopropylidene)diphthalic anhydride (6FDA), B is 2,4,6-trimethyl-m-phenylenediamine (DAM), and C is 3,5-diaminobenzoic acid (DABA) and the ratio of C to B is 1:16 to 2:3.

8. The method of claim 7 , wherein the bulky diamino compound D comprises 2,2′-bis(trifluoromethyl)benzidine (2CF3); 5-(trifluoromethyl)-1,3-phenylenediamine; 4,4′-(9-fluorenylidene)dianiline (CF3); or mixtures thereof.

9. The method of claim 1 , wherein 2 to 5 mole % of the total diamino monomers comprise a bulky diamino compound.

10. The method of claim 1 , wherein the bulky diamino compound comprises 2,2′-bis(trifluoromethyl)benzidine (2CF3); 5-(trifluoromethyl)-1,3-phenylenediamine; 4,4′-(9-fluorenylidene)dianiline (CF3); or mixtures thereof.

11. The method of claim 1 , wherein the monomers comprise a dianhydride monomer, a diamino monomer without carboxylic acid functional groups, and no diamino monomer with carboxylic acid functional groups, wherein 2 to 10 mole % of the total diamino monomers comprises a bulky diamino compound.

12. The method of claim 1 , wherein the monomers consist essentially of a dianhydride monomer and a diamino monomer without carboxylic acid functional groups, wherein 2 to 10 mole % of the total diamino monomers comprise a bulky diamino compound.

13. The method of claim 1 , wherein the ratio of diamino monomer with carboxylic acid functional groups to diamino monomer without carboxylic acid functional groups is 1:16 to 2:3.

14. The method of claim 13 , further comprising a step of treating the polyimide with a mono-alcohol at esterification conditions after preparing the polyimide in step (a).

15. The method of claim 1 , wherein the polyimide has an average molecular weight of 100,000 to 300,000 as measured by Gel Permeation Chromatography.

16. The method of claim 1 , wherein the membrane of step (b) exhibits a CO 2 permeance of at least 20 GPU and a CO 2 /CH 4 selectivity of greater than 20, measured at 35° C. and a pressure of 100 psia.

17. The method of claim 1 , wherein the membrane of step (b) exhibits a CO 2 permeance of at least 40 GPU and a CO 2 /CH 4 selectivity of greater than 20, measured at 35° C. and a pressure of 100 psia.

18. The method of claim 1 , wherein the membrane of step (b) exhibits a CO 2 permeance of at least 40 GPU and a CO 2 /CH 4 selectivity of greater than 20, measured at 35° C. and a pressure of 400 psia.

19. The method of claim 1 , wherein the membrane is an uncrosslinked hollow fiber membrane and the method further comprises spinning the hollow fiber from the polyimide polymer.

20. The method of claim 1 , further comprising coating the membrane comprising uncrosslinked polyimide with polydimethylsiloxane.

21. A hollow fiber polymer membrane comprising a polyimide membrane material made from a polyimide having an average molecular weight of at least 50,000 and including the monomers A+B+D+optionally C; wherein:
A is a dianhydride of the formula:

where X 1 and X 2 are the same or different halogenated alkyl group, phenyl or halogen; and
R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 are H, alkyl, or halogen;
B is a diamino cyclic compound without a carboxylic acid functionality;
C is a diamino cyclic compound with a carboxylic acid functionality; and
D is a bulky diamino compound which is different from diamino cyclic compounds B and C; and

wherein 2 to 10 mole % of the total diamino monomers comprise the bulky diamino compound D, and the ratio of C to B is 0 to 2:3;
wherein the polyimide membrane material comprises less than 30% by weight crosslinks.

22. The membrane of claim 21 , wherein the ratio of C to B is 1:16 to 2:3.

23. The membrane of claim 21 , wherein the ratio of C to B is 0 to 1:16.

24. The membrane of claim 21 , wherein the polyimide includes no diamino monomer with carboxylic acid functional groups C.

25. The membrane of claim 21 , wherein the polyimide membrane material comprises less than 10% by weight crosslinks.

26. The membrane of claim 21 , wherein the polyimide membrane material comprises essentially no crosslinks.

27. The membrane of claim 21 , wherein the less than 30% by weight crosslinks are ester crosslinks.

28. The membrane of claim 21 , wherein A is 4,4′-(hexafluoroisopropylidene)diphthalic anhydride (6FDA), B is 2,4,6-trimethyl-m-phenylenediamine (DAM), and C is 3,5-diaminobenzoic acid (DABA).

29. The membrane of claim 21 , wherein the bulky diamino compound D comprises 2,2′-bis(trifluoromethyl)benzidine (2CF3); 5-(trifluoromethyl)-1,3-phenylenediamine; 4,4′-(9-fluorenylidene)dianiline (CF3); or mixtures thereof.

30. The membrane of claim 21 , wherein the polyimide has an average molecular weight of 100,000 to 300,000 as measured by Gel Permeation Chromatography.

31. The membrane of claim 21 , wherein 2 to 5 mole % of the total diamino monomers comprise a bulky diamino compound D.

32. The membrane of claim 21 , wherein the dianhydride monomer A comprises 4,4′-(hexafluoroisopropylidene)diphthalic anhydride (6FDA), the diamino monomer without carboxylic acid functional groups B comprises 2,4,6-trimethyl-m-phenylenediamine (DAM), the diamino monomer with carboxylic acid functional groups C comprises 3,5-diaminobenzoic ac

Assignees

• Chevron Usa Inc
• Georgia Tech Res Inst

Inventors

• Miller Stephen Joseph
• Koros William John
• Li Nanwen
• Liu Gongping

Classifications

• B01D53/228

  characterised by specific membranes · CPC title

• C08G73/101

  containing chain terminating or branching agents · CPC title

• B01D67/0006

  by chemical reactions (in-situ polymerisation, polycondensation, cross-linking or reaction for manufacturing composite membranes B01D69/125) · CPC title

• C08G73/1028

  characterised by the process itself, e.g. steps, continuous · CPC title

• C09D183/04

  Polysiloxanes · CPC title