Development of a Toughened Bismaleimide Resin Matrix for use in Advanced Composites

Abstract

A high performance toughened bismaleimide resin formulation suitable for use in advanced composites has been developed. The material, coded V391, exhibits high levels of toughness not previously demonstrated with high temperature resin matrices. When combined with intermediate modulus carbon fibers, such as Hitex 46-8B, composite laminates yield a post impact compression strength of 35 Ksi (after an impact of 1500 in lb/in). The resin system posesses excellent processability using epoxy-like cure cycles. Prepreg exhibits good tack and drape, and the resulting composite laminates show an excellent balance of mechanical properties including resistance to microcracking from thermal cycling. This paper outlines the properties of this resin system and describes the effect of cure and post-cure variations on composite properties.