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.

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In this paper, epoxidized solution‐polymerized styrene butadiene rubber (ESSBR) as the matrix and silica as filler, a small quantity of 3‐aminopropyltriethoxysilane (APTES) is used to adjust the cross‐linking network of ESSBR/silica. The effect of two APTES addition methods (ESSBR/APTES/silica and ESSBR/silica/APTES) on the nanocomposite properties is investigated. The epoxy groups of ESSBR and the ethoxy groups of APTES can react with the hydroxyl groups on silica to improve dispersion. At the same time, the amino groups at another end of APTES can react with the epoxy groups of ESSBR to increase the cross‐linking density. Compared with bis(3‐triethoxysilylpropyl) disulfide (TESPD) modified SSBR/silica (SSBR/TESPD/silica), ESSBR/APTES/silica shows 133% improvement in wet‐skid resistance, 14% reduction in rolling resistance with less silane coupling agent and volatile organic compounds emissions. ESSBR/APTES/silica has excellent overall performance and offers a good prospect for the preparation of green tire tread.Highlights APTES modified silica/ESSBR nanocomposites are prepared. Epoxy groups and APTES react with silica to improve dispersion. APTES can increase the cross‐linking density. The nanocomposite has excellent comprehensive performance as green tire tread. The nanocomposite has less silane coupling agent and VOCs emission.

Blending a solution of polymerized styrene−butadiene rubber (SSBR) with natural rubber (NR) as a matrix and silane coupling agent (SCA) modified silica as filler is widely used to prepare green tire tread. However, it is difficult to adjust the distribution of silica in different phases of a rubber blend by SCA. Moreover, the coupling reaction between silica and SCA emits volatile organic compounds. In this work, we use a new strategy to improve the distribution of silica in two phases without a SCA. Epoxidized SSBR (ESSBR) and epoxidized NR (ENR) are synthesized, and the performance of silica-filled ESSBR/ENR nanocomposite (S-ESSBR12/ENR) is investigated and compared with that of silica-filled SSBR/NR nanocomposite (S-Si75-SSBR/ NR) using Si75 as the SCA. The S-ESSBR12/ENR nanocomposites have stronger interfacial interaction that results in better silica dispersion than the S-Si75-SSBR/NR nanocomposite. The epoxy groups can effectively adjust the phase selective distribution of silica. The S-ESSBR12/ENR18 nanocomposite shows homogeneous distribution, leading to the best performance. Compared with S-Si75-SSBR/NR nanocomposite, S-ESSBR12/ENR18 nanocomposite increases wet-skid resistance by 118%, reinforcing index by 38%, and abrasion resistance by 40% and decreases rolling resistance by 23%. Moreover, S-ESSBR12/ENR nanocomposites are ecofriendly and have potential application in the production of green tire treads.