Synthesis and properties of a polyimide containing pendant sulfophenoxypropoxy groups

The synthesis and properties of polyimide containing pendant sulfophenoxypropoxy groups was investigated. 3,3′- Dihydroxybenzidine (98%), Glacial acetic acid (99.7%), 1,3-dibromopropane (98.0%), potassium carbonate, (99.5%), anhydrous acetonitrile (99.5%), hydrochloric acid (35-37%)and benzoic acid (99.5%) was used. The proton conductivity and effect of aliphatic groups on hydraulic and oxidative stability, was analyzed. Diamine monomer containing pendant sulfophenoxypropoxy group was synthesized by reaction of 3,3′- dihydroxybenzidine with dibromopropane under basic conditions. Then, diamine monomer was polymerized with TCND in an m-cresol to obtain polyimide containing pendent acidic groups. It was observed that asymmetric stretching vibrations of the sulfonic acid group showed absorption for imide groups at 1349, 1674, and 1713 cm^-1. Result shows that polymer was synthesized via acetylation, bromoalkoxylation, sulfophenoxylation, and acidification of diamine.