Cross-Linking Reactions of Thermally Stable High Performance Polymers.

摘要

The relationships between the structures and the morphology, solution properties and mechanical properties of polyquinolines depend upon the manner in which the quinoline units are linked together. A wide variety of structures account for polyquinolines that either are amorphous, soluble in common organic solvents and have moderately high glass transition temperatures (approx. 250C) or are crystalline, are soluble only in acidic solvents, forming anisotropic solutions, and have high crystalline transition temperatures (greater than 500 C). The conducting properties of certain doped polyquinolines containing either total conjugation or sulfur linkages between quinoline units are described. Graphite reinforced composites were prepared from biphenylene end-capped polyquinoline and polyimide pre-polymers. The composites demonstrated excellent initial properties and low weight loss after oxidative aging at 316 C. However, the mechanical properties were severely diminished after aging for 50-100 h at 316 C in air and photomicrographs of the composites after aging showed the presence of voids.