A modified imidazole as a novel latent curing agent with toughening effect for epoxy

Abstract

α, β-unsaturated diester was used to react with secondary amine in imidazole ring and also restrain its reactivity. The modified imidazole would thermally decompose into imidazole and unsaturated diesters. Mixture of the latent curing agent with epoxy resins has long storage stability at room temperature for more than one month. The curing behavior of modified imidazole/epoxy was investigated by nonisothermal differential scanning calorimetry method and the curing kinetics results revealed that the modified imidazole has higher curing temperature but similar apparent activation energy. Furthermore, the modified imidazole brings better impact strength for cured epoxy.