High‐performance composites from polyimide matrix resins that utilize a cross linking reaction of biphenylene end‐caps with acetylene units in the main chain

Abstract

Abstract Graphite‐reinforced composites were prepared with oligomeric polyimides having biphenylene end‐caps and acetylene linkages in the polymer chain. The oligomers were crosslinked by the reaction of the biphenylenes with the diphenyl acetylenes to form 9,10‐diphenylphenanthrene units. The resulting composites had good mechanical properties. Thermal oxidative aging studies show that the unidirectional graphite fiber composites maintained good mechanical properties up to 1200 h at 316°C.