Studies on polyimides. Part 1: Synthesis of model compounds and their reaction with hexamethylenetetramine

The synthesis of a series of N-(hydroxyphenyl) succinimides is described along with their reaction with HMTA. The succinimides serve as a model for the more complicated polyimide/HMTA systems. Both benzoxazine and benzylamine type intermediates have been identified as the initial major intermediates formed depending on the substitution pattern of the phenolic ring. The rate of reaction of HPI;ITA with the N-(hydroxyphenyl) succinimide compounds was measured via C-13 nuclear magnetic resonance spectroscopy. It was found that the presence of the succinimide ring increases the reactivity to HMTA of the hydroxyphenyl compounds studied. (C) 1998 Elsevier Science Ltd. All rights reserved.