Patent ID: 9567436
Date: 2017-02-14
CPC Classifications: B01D,C08G,C08L,Y02C

Claim:
1. A method of preparing an aromatic block polyimide polymer comprising both hydroxyl functional groups and carboxylic acid functional groups that comprises: (a) a polycondensation reaction of 2,2′-bis-(3,4-dicarboxyphenyl) hexafluoropropane dianhydride with 3,5-diaminobenzoic acid in a polar solvent at room temperature to form 2,2′-bis-(3,4-dicarboxyphenyl) hexafluoropropane dianhydride-3,5-diaminobenzoic acid-based poly(amic acid); (b) adding 3,3′-dihydroxy-4,4′-diamino-biphenyl monomer to 2,2′-bis-(3,4-dicarboxyphenyl) hexafluoropropane dianhydride-3,5-diaminobenzoic acid-based poly(amic acid) followed by the addition of 2,2′-bis-(3,4-dicarboxyphenyl) hexafluoropropane dianhydride monomer to the solution dropwise to form 2,2′-bis-(3,4-dicarboxyphenyl) hexafluoropropane dianhydride-3,5-diaminobenzoic acid-based poly(amic acid)-block-2,2′-bis-(3,4-dicarboxyphenyl) hexafluoropropane dianhydride-3,3′-dihydroxy-4,4′-diamino-biphenyl-based poly(amic acid) solution; and (c) carrying out a solution chemical imidization of 2,2′-bis-(3,4-dicarboxyphenyl) hexafluoropropane dianhydride-3,5-diaminobenzoic acid-based poly(amic acid)-block-2,2′-bis-(3,4-dicarboxyphenyl) hexafluoropropane dianhydride-3,3′-dihydroxy-4,4′-diamino-biphenyl-based poly(amic acid) in the presence of acetic anhydride dehydrating agent and pyridine imidization catalyst to form poly(2,2′-bis-(3,4-dicarboxyphenyl) hexafluoropropane dianhydride-3,5-diaminobenzoic acid)-block-poly(2,2′-bis-(3,4-dicarboxyphenyl) hexafluoropropane dianhydride-3,3′-dihydroxy-4,4′-diamino-biphenyl) block copolyimide, wherein said poly(2,2′-bis-(3,4-dicarboxyphenyl) hexafluoropropane dianhydride-3,5-diaminobenzoic acid)-block-poly(2,2′-bis-(3,4-dicarboxyphenyl) hexafluoropropane dianhydride-3,3′-dihydroxy-4,4′-diamino-biphenyl) block copolyimide comprises multiple blocks of Ia and multiple blocks of Ib, block Ia and block Ib are covalently bound to each other, block Ia and block Ib are represented by: wherein said block Ia comprises about 1-99 mol % of a total of the blocks Ia and blocks Ib; wherein —R is selected from the group consisting of —H, COCH wherein said poly(2,2′-bis-(3,4-dicarboxyphenyl) hexafluoropropane dianhydride-3,5-diaminobenzoic acid)-block-poly(2,2′-bis-(3,4-dicarboxyphenyl) hexafluoropropane dianhydride-3,3′-dihydroxy-4,4′-diamino-biphenyl) block copolyimide is fabricated into a membrane configuration.