Structure and Performance of Silica-Grafted Epoxidized Solution-Polymerized Styrene-Butadiene Nanocomposites

In the present paper, epoxidized solution-polymerized styrene-butadiene (ESSBR) is successfully synthesized through an epoxidation reaction with hydrogen peroxide and formic acid aiming to improve the performance of silica/SSBR nanocomposites without a silane coupling agent (SCA). A safer and milder reaction condition of H₂O₂/C = C/HCOOH (0.36/2/0.6) is obtained. The silica/ESSBR nanocomposites are prepared by grafting silica nanoparticles on the ESSBR matrix, and the influence of various epoxidation degrees on the structure and performance is investigated. The silica/ESSBR with epoxidation degree 13.8% (silica/ESSBR13.8) shows excellent comprehensive performance on account of the potent interfacial interaction and a uniform dispersion of silica nanoparticles. Compared with the silica/SSBR nanocomposite using Si69 as the SCA (silica/SSBR-Si69), silica/ESSBR13.8 enhances the modulus at 300% strain by 46.8%, reinforcing index by 29.1%, wet-skid resistance by 80.8%, and abrasion resistance by 32.8%. The silica/ESSBR nanocomposites are environmentally friendly and have potential applications in green tires.