Tris(3‐aminophenyl)Phosphine oxide‐based nadimide resins. II

A series of phosphorus‐containing nadimide end‐capped resins having different backbones was prepared by reacting endo ‐5‐norbornene‐2‐3‐dicarboxylic acid anhydride (nadic anhydride), pyromellitic dianhydride (PMDA)/3,3′,4,4′‐benzophenone tetracarboxylic acid dianhydride (BTDA)/2,2‐bis(3,4‐dicarboxyphenyl)hexafluoropropane dianhydride (6F) and tris(3‐aminophenyl)phosphine oxide (TAP) in glacial acetic acid/acetone. Structural characterization of the resins was done by elemental analysis, FTIR, and 1 H‐NMR. Thermogravimetric studies revealed a multistep decomposition reaction for uncured resins. Residual weight at 800°C in nitrogen was found to be 50–60%. Resins cured at 300°C for 1 h in air atmosphere were stable up to 440 ± 20°C and decomposed in a single step above this temperature. The char yields of cured resins were in the range 63–71.5%. © 1992 John Wiley & Sons, Inc.