A New Modifier for Silica in Reinforcing SBR Elastomers for the Tyre Industry

A new alkoxysilane was used to reduce the hydrophilic character of the silica used in reinforcing styrene/butadiene elastomers for the tyre industry. The surface properties of silica modified with 17 wt.-% of this silane were estimated by inverse GC. A clear change from hydrophilic to hydrophobic character was observed. Styrene/butadiene copolymers loaded with modified silicas were characterized using vulcanization tests, stress/strain measurements and morphological analysis. The best tensile properties were obtained with TESPT-modified silica. The properties of the compound loaded with sb1-pre-grafted silica are scantily lower that the ones of the other compounds. This difference must be ascribed to a higher crosslink density given by the sulfur deriving from the TESPT decomposition during the vulcanization process.