Abstract
Epoxy resin was modified with ethylene-based copolymer. Two types of ethylene-based copolymers were used in this study; ethylene acrylic rubber and ethylene-based ionomer/clay nanocomposite. For the ethylene acrylic rubber-modified epoxy, three types of hardeners were used and the effect on microstructure and mechanical properties (dynamic viscoelasticity and fracture toughness) was investigated. The hardener considerably affected the microstructure, and this led to the differences in dynamic mechanical properties. The fracture toughness values were not so much improved. For the ionomer/clay-modified epoxy, effect of hardener content on mechanical properties was investigated because ionomer is expected to react with epoxy resin. The dynamic viscoelastic tests showed that the glass transition temperature (Tg) was increasing with decreasing the hardener content. For one resin system, the Tg disappeared and thermal resistance was greatly improved. Fracture toughness was decreasing with decreasing the hardener content. In particular, the fracture toughness value of the system without Tg was 40% less than that of the unmodified system. These results can be explained by increase of crosslink in epoxy matrix which were caused by the reaction with epoxy and ionomer.
