Published online by Cambridge University Press: 15 February 2011
A novel toughened epoxy resin was obtained by using an epoxy-terminated prepolymer prepared from epoxy resin and hydroxy-terminated butadiene-acryl-onitrile copolymer (HTBN), and an amine curing agent. The cured, toughened resin has excellent mechanical properties due to the two-phase structure which was observed using SEM and TEM. When the HTBN content is 15 phr, the rubber phase separates effectively and the specimen presents a fine two-phase structure. However, when the HTBN content reaches 25 phr, the morphology appears continuous.