Fracture Toughnesses of Bisphenol a Type Epoxy Resin and Silica Particulate-Filled Epoxy Composite

Abstract

Using Raman spectroscopic analysis and the fractographical analysis, we investigated the relationship between the glass transition temperature, T_g, the fragility parameter, m, and the fracture toughness, K_Ic, of epoxy resin and composite. T_g and m derived from the thermo-viscoelasticity were used to characterize the epoxy resin and composite post-cured under various conditions. The Raman spectroscopic analysis showed that the T_g is directly related to the degree of cross-linking reaction of the epoxy resin and the matrix of composite. The fractography showed that m of the epoxy resin depends on the heterogeneous microstructure. The m of the composite was dominated by the volume fraction. K_Ic of the epoxy resin increased as m decreased when the T_g was saturated at approximately 400K. A composite with a high T_g and a low m had a high K_Ic value.