Optimization of highly dispersible silica/carbon black hybrid filler ratio for tire tread based on solution- and emulsion-styrene butadiene rubber

Abstract

In this study, the effects of hybrid filler ratio and styrene-butadiene rubber (SBR) type on tire tread performance that is, wet grip (WG), fuel-saving efficiency (FSE), and abrasion resistance, were focused. Two types of SBR that is solution-SBR (S-SBR) and emulsion-SBR (E-SBR) were selected and reinforced by various ratios of highly dispersible silica (HDSi) to carbon black (CB). Although increasing the CB ratio had negative effects on WG, FSE, heat build-up, and dynamic set, it improved abrasion resistance. Results revealed a good balance of tire performance at a CB ratio of 40 wt%. Clearly, S-SBR provided better overall tire performance than E-SBR, particularly in the silica-filled system. This is possibly due to the higher glass transition temperature (Tg) and the greater magnitudes of rubber-filler interaction and crosslink density of S-SBR. Surprisingly, the HDSi/CB hybrid ratio and the SBR type had little influence on the degree of filler dispersion, probably because of the sufficiently long mixing time employed in this experiment.