Production of polyimide foams.

摘要

A polyimide precursor mixture having a solids content of 50 to 77 (preferably 65 to 75) weight percent is subjected to a multistaged thermal treatment in which the precursor is heated to one or more temperatures sufficient to obtain a consolidated but friable cellular foam structure, and the resultant cellular foam structure is then subjected to one or more higher temperatures sufficient to cure the cellular material into a resilient polyimide foam. There is no need for use of time-consuming and expensive spray drying and microwave radiation apparatus.