Lower-curing-temperature PMR polyimides

Partial substitution of a p-aminostyrene end-cap for the monomethyl ester of 5-norbornene-2, 3-dicarboxylic acid lowered the final cure temperature of typical PMR resins from 600 F to 500 F. The weight loss characteristics of neat resins and graphite fiber composites prepared by using the mixed end-cap approach were determined at 600 F. The room temperature and short-time elevated temperature mechanical properties of the composites at 550 F and 600 F were determined. The mechanical property retention characteristics of the composites at 550 F and 600 F are discussed. Previously announced in STAR as N83-10118