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

Abstract

Abstract 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.