Effect of silane coupling agent on the structure and mechanical properties of nano-dispersed clay filled styrene butadiene rubber

In rubber nanocomposites containing inorganic clay, the reinforcement effect has always been relatively insignificant due to the poor interfacial interaction between the rubber matrix and clay fillers. In this work, the silane coupling agent bis[3-(triethoxysilyl)propyl]tetrasulfide (Si-69) was employed through mechanically blending with styrene butadiene rubber (SBR)/clay (100/30) nanocompound that was prepared by combined latex compounding and spray-drying technique, to serve as the molecular bridge between SBR matrix and clay filler and strengthen the interfacial interaction. TEM and XRD characterization indicated that Si-69 significantly improved the dispersion of the silicate layers in the SBR matrix. The RPA analysis and the mechanical property study of the SBR/clay nanocomposites revealed that the filler network interaction was weakened while the filler-rubber interaction was strengthened upon the addition of Si-69.