Study on epoxy resin toughened by epoxidized hydroxy-terminated polybutadiene

Epoxy resin (EP)was toughened by epoxidized hydroxy-terminated polybutadiene (EHTPB), with the corresponding modified epoxy resin being prepared. In this paper, the microstructure of EHTPB-modified epoxy resin was characterized, while the influence of different contents of EHTPB on curing kinetics, mechanical properties, morphology, thermal properties, dynamic thermomechanical (DMA) properties and crosslink density of the modified epoxy resin were also discussed. The results showed that the EHTPB-modified epoxy resin was successfully prepared and cured completely. The activation energy (E_a) of the modified epoxy resin decreased after the addition of EHTPB. With an increase in the EHTPB content, the tensile strength (σ_m) of the modified epoxy resin decreased and the breaking elongation (ε_b) increased gradually. The initial decomposition temperature (T_5%) and glass transition temperature (T_g) of the modified epoxy resin decreased with an increase in the EHTPB content. The modified epoxy resin had a rough fractured surface and the interface was blurred, presenting a ductile fracture.