Study On Epoxy Resin Adhesive Toughened By Amino-Terminated Polyurethane

In this paper, amino-terminated polyurethane (ATPU), the tough curing agent with special structure for epoxy resin, was synthesized. First, the isocyanate group-terminated oligomers were prepared through polyethylene glycol (PEG) and TDI, and then ATPU was further synthesized with m-XDA and the epoxy resin adhesive system was formed through ATPU as a tough curing agent. The effect of the amount of curing agent and the molecular weight of ATPU, the amount of accelerant and coupling agent and the curing conditions on mechanical properties of epoxy adhesive system were investigated. Results showed that when the molar ratio of epoxy functional group/-NH₂ was 1:0.7, curing conditions were 80℃×6hr plus120℃×3hr and the weight of accelerant was 2% of that of E-44 epoxy resin, epoxy resin (E-44) adhesive toughened by ATPU-3 had the best mechanical properties.The reaction mechanism of the epoxy adhesive was analyzed through IR, the thermal stability of epoxy system was evaluated through TGA and the fracture surface morphology of the system was observed through SEM. The results showed that the toughness of the curing system modified improved remarkably and the fracture surface morphology of the tough curing agent...