抄録
Epoxy resins are utilized in various industrial areas as adhesives and matrix of composite materials. Epoxies are one of the network polymer and their crosslink density are mainly dominant of the mechanical behaviors. However the microstructures which is formed during curing process are not well known. In this study the effect of network structure of matrix resin on the fatigue crack propagation properties of rubber-toughened epoxy resin. Several DGEBA epoxy resins with different average molecular weight were used in this study. Core shell rubber (CSR) particles were well dispersed in the epoxy. Whereas the fracture toughness of CSR-modified epoxy monotonously enhanced with increasing molecular weight between crosslinks (Mc), the fatigue threshold had a peak against Mc. The size of the plastic deformation zone was well related to the fatigue resistance.
