Toughness improvement of PMR-type polyimide and laminated graphite systems by ex-situ concept

In this paper, a thermosetting polyimide model matrix resin and laminated systems made of the polyimide were investigated. The polyimide denoted as LP-15 was an own development of the National Key Laboratory. Recently, we developed a new concept to significantly increase the CAI properties of laminated-graphite systems by periodically interleaving solid thermoplastic thin films into the graphite plies. This so-called ex-situ concept, has successfully been demonstrated in many epoxy-based laminates. It is likely an all-purposed concept for toughening any laminate independent of the chemistry of matrix resins. Hence, it was expected that ex-situ concept could also be applied to PMR-type polyimide based graphite laminates.