SYNTHESIS AND PROCESSING OF MODEL-COMPOUND OF PMR-15 RESIN

Aerospace industries have been concerned since long by composite mater ials using highperformance resins. The PMR-15 resin is now the most co mmonly used resin for industrial applications at high temperature, i.e ., 300 degrees C. Despite its comparative commercial success, the PMR- 15 resin and its composites show several disadvantages [toxicity of th e aromatic diamine (MDA), poor conservation of monomers solution, lami nate microcracking]. The purpose of this work concerns the synthesis, the physico-chemical characterization, and the processing of pure bisn adimide model compound to study the endo/exo isomerization of the endc aps and thermomechanical properties. We show that the isomerization me chanism proceeds by retro Diels-Alder reaction followed by recombinati on in exo isomer and glass temperature transition is upper than 350 de grees C (380 degrees C). (C) 1997 John Wiley & Sons, Inc.