Synthesis of benzophenone tetracarboxylic dianhydride and pyromellitic dianhydride incorporated biscitraconimides and their thermal polymerization

Biscitraconimides incorporated with 3,3′,4,4′-benzophenone tetracarboxylic dianhydride (BTDA) and pyromellitic dianhydride (PMDA) were synthesised. Their curing behavior as well as thermal stabilities were investigated. The intermediate amic acids were prepared by the reaction of 4-amino 4′-citraconamic acid diphenyl sulphone, 4-amino 4′-citraconamic acid diphenyl ether, and 12-amino 1-citraconamic acid dodecane with BTDA and PMDA, respectively. Six amic acids formed were then imidized by cyclocondensation with acetic anhydride. The imide monomers were obtained and these were cured at 225–240°C. The thermal stabilities of the polymers so formed were investigated and compared. © 1996 John Wiley & Sons, Inc.