Mechanical properties of epoxy resin composites modified by epoxy styrene-butadiene latex

To improve toughness, crack resistance, and other mechanical properties of cured epoxy resins (EP), styrene-butadiene rubbers (SBR) with epoxy groups named as ESBR were fabricated by emulsion polymerization and directly blending with EP in form of latex to make EP/rubber composites. Dispersity and compatibility of ESBR in epoxy resin were significantly improved. The results showed that impact strength for epoxy resin composite was up to 35.28 KJ/m(2) when 8 phr ESBR with epoxy degree of 11% (ESBR-11) was added, which was 127% higher than that of pure EP (15.18 KJ/m(2)). Toughness, bending strength, and tensile strength were simultaneously improved when the addition amount for ESBR-11 was 2 phr. Compared with EP modified by SBR latex, butadiene vinyl-pyridine rubber latex, carboxylate styrene-butadiene latex and ESBR dissolved in chloroform, ESBR latex can significantly enhance mechanical properties of EP due to the uniform dispersion, good compatibility and strong chemical bonding between components.