Effect of Particle Size Distribution of Silica Fillers on Rheometric Properties of Styrene Butadiene Rubber Compounds

Various characteristics of fillers, such as particle size and size distribution affect properties of composites. In this work, the effect of simultaneous use of nanosilica and microsilica fillers with different ratios on rhometric properties of styrene-butadiene rubber vulcanizates was studied. Surface modification of nano- and micro- fumed silica was performed by using 3-methacryl oxypropyl-trimethoxysilane (MEMO) coupling agent. Rubber compounding was carried out in melt mixing. The filler particles dispersion and size distribution in the compounds were analyzed by scanning electron microscopy. The oscillating die rheometer (ODR) was used for rheometric studies. It was observed that at a constant volume fraction of filler, reduction in the amount of micro-silica by replacing with nano-silica increases the viscosity and modulus of the compound before and after vulcanization, respectively. This synergic effect was observed at about 25% by weight of nano-silica