Electron beam cured resins and composites: Improved two-step curing materials for cryogenic applications

There are two major families of resins that cure with electron beams, the cationic epoxies and the vinyl compounds. The vinyl resins, such as acrylates, can be cured in the presence of nucleophilic compounds present in the formulation or on the fibers, while the cationic epoxies cannot cure under these conditions. SRL and partner Drexel University are continuing to develop and improve two-step cured resins that utilize low temperature epoxy curing combined with electron beam curing to form thermoset networks for carbon fiber composites. The goal of the present program is to toughen these resins, extend the use temperature range and evaluate their properties at temperatures extending from that of liquid hydrogen to at least 120°C. Results of thermal and mechanical testing of both cured resins and continuous fiber composites prepared from the same resins will be discussed.