TOUGHENING PROCEDURES, PROCESSING AND PERFORMANCE OF BISMALEIMIDE CARBON-FIBER COMPOSITES

Toughening procedures, processing optimization and performance evaluation of bismaleimide (BMI)-carbon fibre composites are reported. The BMI matrix was 4,4'-bismaleimidodiphenylmethane (BMPM)/O,O'-diallyl bisphenol A (DABPA). Toughening procedures involved (i) characterization and optimization of the BMI cure reactions to produce 'defect-free', fully cured crosslinked networks, and (ii) incorporation of viscoelastic toughening poly(ether imide) (PEI) particulates and film interleaves and crack deflector Kevlar 49 whiskers into the BMI-carbon fibre composites. Optimization of composite processing conditions is reported. The effects of toughening procedures on composite performance in terms of G(Ic) toughness, impact penetration, compression after impact and open hole compression as a function of temperature are discussed. The conflicting requirements of these performance tests upon desirable polymer matrix properties are critically discussed.