ゴム変性エポキシ樹脂の相分離構造と機械的性質

抄録

The morphology of phase-separation and the mechanical properties of amine cured rubber-modified epoxy resins were investigated.
The results of the dynamic mechanical properties and the microscopic observations indicated that the epoxy-rich matrix phase was plasticized by the dissolved rubber and the rubber-rich domains were dispersed homogeneously in the epoxy-rich matrix.
The rubber-modification of epoxy resins enhanced the fracture toughness against crack initiation and caused the crack arrest. The size of the plastic-deformed region at the crack tip was correlated well with the fracture toughness against crack initiation according to Dugdal's equation.
From the fatigue crack propagation (FCP) tests at a low frequency it has been shown that the presence of rubber domains introduces the interfacial debonding between the domain and the matrix as the result of stress response, which promotes the FCP at the low stress intensity factor range.