Addition polyimides. I

Abstract Crosslinking of 4,4′(bismaleimido)diphenyl ether (BM) was investigated in presence of bis(m‐aminophenyl)methylphosphine oxide (BAP), tris(m‐aminophenyl)phosphine oxide (TAP), diaminodiphenyl ether (E) and 3,3‐bis(p‐aminophenyl)phthalide (AP). These crosslinked resins were examined for thermal stability by thermogravimetric analysis. A slight decrease in initial decomposition temperature, the temperature of maximum rate of weight loss, was observed, though the char yield in nitrogen atmosphere at 800°C did not change appreciably. Glass‐cloth‐reinforced laminates were fabricated from BM and amine mixtures. An improvement in mechanical properties was observed in the presence of phosphorus‐containing di‐ and triamines.