Polyimides and polyamide–imides containing arylene sulfone ether linkages

Abstract Polyimides and polyamide–imides containing arylene sulfone ether linkages were synthesized from 4,4′‐bis(4‐isocyanatophenoxy) diphenylsufone (SPI), 4,4′‐bis(3‐isocyanatophenoxy) diphenylsulfone (SMI), pyromellitic dianhydride (PMDA), 3,3′,4,4′‐benzophenone tetracarboxylic dianhydride (BTDA), and trimellitic anhydride (TMA) using one‐step method. The diisocyanates SPI and SMI were synthesized from 4,4′‐bis (4‐carboxyphenoxy) diphenylsulfone (SPA) and 4,4′‐bis(3‐carboxyphenoxy) diphenylsulfone (SMA) by a Weinstock‐modified curtius rearrangement method. All the polycondensation reactions were carried out in N ‐methyl‐2‐pyrrolidone (NMP) and the polymers obtained were characterized by infrared spectroscopy, solution viscosity, elemental analysis, thermogravimetric analysis, differential scanning calorimetry, and X‐ray diffraction.