The combination of montmorillonite and silica in styrene–butadiene rubber/polybutadiene rubber tread compounds

Montmorillonite and silica were used as fillers combined with Si69 as their coupling agent in styrene–butadiene rubber/polybutadiene rubber tread compounds to evaluate their interaction and influences on structure and properties of nanocomposites. Microstructure, filler dispersion, curing properties, and tire performance of the compounded rubber were investigated with the aid of X‐ray diffraction, transmission electron microscopy, rheometer, and dynamic‐mechanical analysis, respectively. The results showed that montmorillonite could react with coupling agent and their reaction rate was higher than silica/Si69. The dispersion and exfoliation was promoted by the existence of silica. Fully exfoliated montmorillonite were formed when the montmorillonite/silica ratio was 14 or lower, and the as‐prepared rubber compounds displayed well‐balanced properties. Additionally, coupling agent also influenced the curing kinetics, dynamic, and mechanical properties of the tread compounds. But the structure was not affected by the usage amount of Si69. POLYM. COMPOS., 38:918–926, 2017. © 2015 Society of Plastics Engineers