2016-08-242016-08-241993-03-16http://hdl.handle.net/10919/72795The imidization temperature of poly(amide-acid) compositions derived from tetracarboxylic acid dianhydrides can be lowered by use of a bis(aminophenoxyphenyl) phosphine oxide in the diamine component which is reacted with the dianhydride. These homo- or copolyimides can be cyclized without use of catalysts or excessive temperature which can product undesired side reactions. Tough film forming materials can be produced which show excellent thermo-oxidative stability and high char yields even at 800.degree. C. in air.application/pdfen-USPoly(amide-acid) compositions derived from tetracarboxylic acid dianhyrides capable of solution imidizationPatenthttp://pimg-fpiw.uspto.gov/fdd/65/945/051/0.pdf7735488524/27525/421525/422528/167528/125528/126528/322528/342528/350528/353C08G73/1057C08G79/045194565