Effect of Emulsion and Solution SBR Rubber Blends on Dual‐Filler Reinforcement in PCR Tread Compounds

This study investigates the effect of emulsion styrene‐butadiene (ESBR) and solution styrene‐butadiene (SSBR) rubber blends having different bound styrene and vinyl content in carbon black and silica‐filled systems on tire tread performance. The work initially assessed the roles of rubber blends where variations were achieved out of proportionate mixing of carbon black‐filled composites of emulsion and solution SBR. The study reveals that rubber with a higher content of bound styrene demonstrated improvement in carbon black dispersion, polymer–filler interactions, higher crosslink density, better abrasion resistance, and mechanical properties, showing slower curing and reduced rolling resistance indicator. In contrast, elevated vinyl content showed accelerated curing and improved traction properties. To explore dual filler effects, ESBR‐carbon black and SSBR‐silica composites (80 phr fillers) were prepared and blended systematically. An optimal formulation comprising a 40:60 SSBR and ESBR blend ratio, with bound styrene and vinyl contents of 33% and 34%, respectively, and a silica‐carbon black ratio of 32:48, achieved a 20% reduction in rolling resistance while improving wet grip and abrasion resistance relative to ESBR–carbon black controls. Reduced Payne effect, improved filler dispersion, and stronger polymer–filler interactions were confirmed by electron microscopies. This balanced formulation shows promise for high‐performance tire tread applications.