TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Compound: The dianhydride is an aromatic compound, e.g. pyromellitic dianhydride (preferably), 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 4,4'-(hexafluoroisopropylidene)bis(phthalics anhydride), 4,4'-oxydiphthalic anhydride, diphenylsulfone-3,3'4,4'-tetracarboxylic dianhydride or 3,3',4,4'-biphenyltetracarboxylic dianhydride. The diamine is phenylene diamine, methylene dianiline (MDA), methylene di-o-chloroaniline (MOCA) (preferably), methylene bis(dichloroaniline), methylene dicyclohexylamine, methylene dichlorocyclohexylamine, methylene bis(dichlorocyclohexylamine), 4,4'-(hexafluoroiso-propyledine)-bisaniline, 3,3' -diaminophenyl sulfone, 4,4'-diaminophenyl sulfone, 4,4'-dimethyl-3,3'-diaminohenyl, sulfone, 2,4'-diamino cumene, methylene bis(di-o-toluidine), oxydianiline, bisaniline A, bisaniline M, bisaniline P, thiodianiline, 2,2-bis(4-(4-aminophenoxy)phenyl) sulfone, 4,4'-bis-(4-aminophenoxy) biphenyl, 1,4-bis(4-aminophenoxy) benzene or 1,3-bis(4-aminophenoxy) benzene.    TECHNOLOGY FOCUS - POLYMERS - Preferred Component: The polyimide is derived from 8-20C dianhydride and 2-30C diamine. The polyamine is poly(2-vinylpyridine), poly (4-vinylpyridine), polyethylenimine, and/or polyallylamine. Preferred Composition: The polyamine is included in the membrane in an amount of 30-90 wt.%. The polyimide is included in an amount of 10-70 wt.% . EXAMPLE - A membrane comprising 50 wt.% poly(4-vinylpyridine) and 50 wt.% polyimide was prepared. To a solution containing 4,4'-Oxydianiline (3 g) in dimethylformamide (DMF) (12.4 ml), 4,4'-Oxydiphthalic anhydride (4.75 g) was added gradually under mixing to make the polyamic acid. During the synthesis of the polyamic acid, an additional DMF (2.63 ml) was added to the solution to adjust for increases in the solution viscosity. To the resulting polyamic acid was added a solution of poly(4-vinylpyridine) (7.75 g) in DMF (25.4 ml). An additional DMF 920 ml) was added to the solution. The resulting solution was used to cast a membrane by the technique of knife casting. The cast membrane was placed in a fume hood at ambient temperature overnight to allow evaporation of the DMF:solvent. Following solvent evaporation, the membrane was dried at 120degreesC under nitrogen overnight. As a final step, the membrane was cured for 4.5 hours at 220degreesC under nitrogen. Results showed that thermal gravimetric analysis indicated that the membrane had a thermal stability of 280degreesC.