Structure and Properties of SiO ₂ Filled Epoxidized Natural Rubber/Epoxidized Butadiene Rubber Nanocomposites

ABSTRACT Natural rubber (NR) and cis‐polybutadiene rubber (BR) are usually used as matrix and silane coupling agent modified SiO ₂ as filler to prepare tire tread. However, due to the differing affinities of the filler toward each rubber phase, it tends to preferentially disperse in one phase, leading to partial inhomogeneity of filler distribution between the two phases and ultimately compromising the overall performance of the nanocomposite. In this work, epoxidized NR (ENR) and epoxidized BR (EBR) with different epoxide degrees are synthesized through in situ epoxidation, and then blended with TESPT‐modified SiO ₂ to prepare the corresponding nanocomposites ENR/EBR‐ x /SiO ₂ . With the epoxide degree of EBR increasing, the filler‐rubber interaction is enhanced, leading to improved SiO ₂ dispersion and phase distribution within the rubber matrix, as well as enhanced compatibility between the ENR and EBR phases. Compared with the conventional NR/BR/SiO ₂ system, the prepared ENR/EBR‐15/SiO ₂ nanocomposite achieves a more balanced “magic triangle” of tire tread performance, including a 94% improvement in wet‐skid resistance, an 18.8% reduction in rolling resistance, and a 6% reduction in abrasion volume. Furthermore, the tensile strength is enhanced by 11.5%, and the dynamic heat build‐up is reduced by 3.8°C. This study provides a promising strategy for the design of high‐performance tire tread nanocomposites.