Abstract
In this paper, heterogeneity effect on mechanical properties was investigated for epoxy resin blended by two monomers: Epikote 828 and Epikote 1001, with several mixture ratios. Epikote 828 was blended with Epikote 1001 before curing on purpose to induce heterogeneity in epoxy resin. In order to characterize degrees of the cross linking and heterogeneity in the resin, the glass transition temperature and the fragility were determined from thermoviscoelastic properties. Comparing with the dynamic storage modulus E' and the fracture toughness, G_<IG>, it was clarified that high heterogeneity in the epoxy resin affected high E' and low G_<IC> due to the mobility of the resin. The fragility is efficient parameter to characterize heterogeneity related to mechanical properties.
