Study on the modified epoxy resin system as composite matrix cured under low temperature

摘要

It was accepted that epoxy should be cured under low temperature with the same properties as those cured under high temperature, which was an ideal route to improve the processability and performance of composite. The hyperbranched polyesters (HBPs) with 2-methylimidazole as a core were prepared and used as curing agents and tougheners of diglycidyl ether of bisphenol A (DGEBA) in this work. It was found that the tensile strength of epoxy thermosets including HBPs cured under 80 °C(CYD-128/CA1) was close with that of CYD-128/DDS thermoset cured under 120 °C, but their flexural strength and impact strength were much higher than those of CYD-128/DDS thermoset, which indicated that epoxy curing system cured under low temperature had better properties as those cured under high temperature, and the addition of HBPs in the thermoset obviously increased the fracture toughness. It was concluded that the CYD-128/CA1 thermoset cured at 80 °C was proper to be used in composite as resin matrix.