Preparation and mechanical behavior of modified epoxy resin with grafted silicon rubber

Epoxy resin (EP) was modified by grafted silicon rubbers (g-SRs) prepared by co-polymerization of methyl vinyl silicon rubber with vinyl acetate. The branched structure of the g-SRs has been identified by infrared spectrum. The mechanical properties of modified EP were examined and the related fracture surfaces were observed by a scanning electron microscope. The results indicated that the EPs have been reinforced and toughened obviously by the addition of g-SRs. The mechanical properties of modified EPs depended not only on synthesis processes of co-polymerization, but also on the amount of the g-SRs added. The best combination of tensile and impact strengths for the cured modified EPs have been reached by that modified with 15 phr g-SRs. The morphology of modified EP is remarkably different from that of the pure cured EP.