Synthesis of sulfonated copolyimides membranes based on NTDA dianhydride and effect of synthetic method on polymer properties

Sulfonated copolyimides (ScoPI) were synthesized with different methods by one-step high temperature direct polymerization in m-cresol solvent. ScoPI molecule structure is formed from 1,4,5,8-Naphthalenetetracarboxylic dianhydride (NTDA). Different methods are include adding benzoic acid at different time levels and reaction time. According to these methods obtained three different production which the most important returned to membrane ability. There had not membrane ability for ScoPI contains 4,4-diaminobiphenyl-2,2-disulfonic acid (BDSA) because synthetic method but ScoPI contains 4,4 diaminostilbene-2,2-disulfonic can form polymer membrane. Membranes were analyzed by FT-IR, Thermogravimetric analysis (TGA), mechanical properties, differential scanning calorimetry (DSC), Water uptake, Ion exchange capacity (IEC) and lambda (λ). In general, ScoPI/DSDSAII was shown significant TGA and mechanical properties than ScoPI/DSDSAII in the same analogues because difference in synthetic method

Keywords:

Sulfonated copolyimide , synthetic method , benzoic acid , membrane ability , one-step high temperature direct polymerization , NTDA