Effects of octamethylcyclotetrasiloxane grafting and silica particle generation on the curing and mechanical properties of a styrene butadiene rubber composite.

The reinforcement of octamethylcyclotetrasiloxane (D) grafted styrene butadiene rubber (SBR--D) with generated silica was performed using the sol-gel reaction of tetraethoxysilane (TEOS) in latex. The characterization of SBR--D and generated silica reinforced SBR--D was investigated by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. The grafting efficiency of the styrene butadiene rubber (SBR) was determined by a gravimetric method. It was found that the constant silicon content and the grafting efficiency of SBR were 1.72% and 0.13 wt% when the weight ratio of D to SBR was 0.20. The effects of the D and generated silica content on the curing characteristics, mechanical properties and morphology of SBR latex were investigated. The mechanical properties of generated silica reinforced SBR--D vulcanizates were improved significantly compared to raw SBR vulcanizate when the generated silica content was 18.05%. Compared with silica reinforced SBR--D, the tensile strength, wet skid resistance and rolling resistance of the generated silica reinforced SBR--D were better. This is because of the higher crosslinking degree in the SBR--D matrix and the strong chemical bond between SBR--D molecular chains and generated silica. Scanning electron microscopy analysis revealed good silica filler dispersion in all the reinforced SBR--D vulcanizates.