A novel strategy to functionalize styrene butadiene rubber toward enhanced interfacial interaction with silica

Incorporation of nanofillers (such as silica) into elastomer matrix is the most common strategy to prepare high-performance rubber products. However, the poor dispersion of nanofillers in non-affinity rubber materials and the weak interfacial interaction significantly limit the processing and mechanical properties. To reduce the polarity difference and enhance the interfacial interaction between silica and styrene butadiene rubber (SBR), we prepared a hydroxyethyl acrylate-grafted SBR (SBR-g-HEA) through the redox initiator system, and subsequently fabricated SBR-g-HEA/silica nanocomposites by simple mechanical blending. The effects of reaction conditions on the grafting rate were studied in detail. ATR-FTIR and ¹H-NMR collectively confirmed the successful grafting of HEA groups on SBR molecular chains, and the grafting fraction could be regulated from 0% to 2.5%. Scanning electron microscope (SEM) and rubber processing analyzer (RPA) showed that the incorporation of HEA could significantly improve the dispersion of silica nanoparticles in SBR matrix. Notably, the resulting SBR-g-HEA exhibited significantly enhanced attributes when compared to their unmodified counterparts, including superior mechanical properties, improved wear resistance, and reduced heat generation. The strategy proposed here provided insights toward the fabrication of non-affinity rubber/filler nanocomposites for high-performance rubber products and green tire.