Excessive radical induced cationic frontal polymerization lead to a decline of material properties

Radical induced cationic frontal polymerization (RICFP) can significantly improve the curing efficiency of epoxy resins. However, conditions such as excessive initiators lead to violent reaction of the frontal polymerization, which will adversely affect the performance of the product. Herein, the effect of the reaction degree on the tensile strength of RICFP-cured bisphenol A epoxy resin was studied, and the optimum ratio was measured by response surface methodology. Components and molecule structures of the products were analyzed by GC/MS, FTIR and XPS. The principle that overreaction affects the tensile strength of products was further explained. In addition, it was found that the epoxy value of resin may determine whether RICFP could be achieved. This could be remedied by adding ethylene glycol diglycidyl ether, which could significantly promote the reactivity. Its principle and overreaction were further studied and explained.