Reinforcing Effects of a Novel Networked Silica on SBR Compounds

A novel three-dimensionally networked silica (NS) was prepared using organic chemical linkage like bis(triethoxysilylpropyl)tetrasulfane (TESPT), and its reinforcing properties on styrene-butadiene rubber (SBR) compounds were investigated in this study. Any pre-cure in the mixing step and ethanol production in the curing step, which were known as the drawbacks of the conventional silica reinforcing system using a silane coupling agent, were not observed. The dispersion of NS was significantly improved in SBR matrix and the SBR compound reinforced by NS showed higher tensile properties than the conventional silica system. The filler-filler interaction decreased and filler-rubber interaction increased in the NS-filled SBR compounds. However, the actual crosslink density of the NS-filled SBR compounds was not greatly changed with increasing filler amounts because the reinforcing effect was made by physical entanglements between rubber chains an d NS, not by chemical reactions. In addition, the physical properties such as hysteresis, dynamic mechanical properties, and abrasion properties of the rubber compounds reinforced by NS will be also discussed.