Synergistic effects of tertiary amine and imidazole accelerators on epoxy resin curing

Abstarct In order to improve the curing rate, this study investigated the influence of various accelerators and their combinations on the curing behavior of epoxy resins. differential scanning calorimetry (DSC) was used to analyze the curing behavior of various accelerators in diglycidyl ether of the bisphenol A epoxy resin and the methyl hexahydrophthalic anhydride curing system, and activation energies were calculated using the Kissinger and Ozawa models. The results indicated a self‐catalytic characteristic in the curing process and showed that the activation energies for tris(dimethylaminomethyl)phenol (DMP‐30) and 1‐cyano‐2‐ethyl‐4‐methylimidazole (2E4MZ‐CN) were significantly lower compared to N , N ‐dimethylbenzylamine, demonstrating higher curing reactivity. Furthermore, a novel strategy combining tertiary amine accelerator (DMP‐30) and imidazole accelerator (2E4MZ‐CN) was proposed and the activation energy variations with the degree of cure were analyzed employing the KAS method. When the mass ratio of DMP‐30 to 2E4MZ‐CN was 1:3, the activation energy was 59.08 kJ/mol, approximately 12% lower than using a single accelerator, which indicated the synergistic effects of the accelerators. Finally, the mechanism of synergistic effect of tertiary amine and imidazole accelerators on epoxy resin curing were proposed.