Next-Generation Rubber Nanocomposites for Reducing Rolling Resistance and Reliable Wet and Winter Grip

Achieving low rolling resistance without compromising wet skid resistance and winter traction remains a central challenge in tire material design, as these properties collectively govern fuel efficiency, on-road safety, and overall tire performance. Polystyrene-block-polybutadiene-block-polystyrene (SBS) nanocomposites are promising materials for advanced tire applications due to their tunable mechanical properties and microphase-separated morphology. However, the inherently polar nature of silica nanoparticles and the non-polar rubber matrix often result in poor filler–polymer compatibility, limiting filler dispersion, interfacial interactions, reinforcement efficiency, and dynamic performance. Conventional silica surface treatments typically rely on VOC-emitting silane coupling agents, raising environmental and health concerns during processing. In this study, phenyl silane is explored as a low-VOC alternative surface modifier to enhance silica–polymer compatibility while improving the sustainability of nanocomposite fabrication. The influence of particle size and phenyl functionalization on polymer–filler interactions and tire-related properties in SBS nanocomposites was systematically investigated. Grafting phenyl groups onto silica nanoparticles enhanced their compatibility with the polystyrene domains of SBS, leading to improved filler dispersion and stronger filler–matrix interactions. NMR spin-relaxation analysis (T1 and T2) provided evidence of non-covalent polymer–filler interactions, while field-emission scanning electron microscopy (FE-SEM) observations confirmed reduced particle agglomeration. Dynamic mechanical analysis demonstrated that smaller phenyl-functionalized silica nanoparticles significantly reduced rolling resistance while simultaneously improving wet skid resistance and winter traction. In addition, LCA was conducted to evaluate the environmental impacts associated with nanocomposite production. The results demonstrate that phenyl silane offers a promising alternative to conventional VOC-emitting silane coupling agents by improving silica–SBS compatibility, enhancing mechanical and dynamic performance, and supporting the development of high-performance, more sustainable SBS-based elastomeric materials for tire, footwear, and other advanced engineering applications.