Effect of the structural characteristics of solution styrene–butadiene rubber on the properties of rubber composites

Solution-polymerized styrene–butadiene rubber (SSBR) has been widely used in the high-quality tire industry, and various brands of SSBR have been synthesized. Five kinds of SSBR were selected from multiple products to investigate the effects of different brands of SSBR on the comprehensive properties. Different characterization tools, such as Fourier transform infrared spectroscopy, ¹H-NMR, and differential scanning calorimetry, were used to characterize the microstructures of the SSBRs. The results show that the microstructures of the SSBRs distinctly affected the comprehensive properties of the SSBR composites, especially the properties of the “magic triangle.” For instance, the content of trans-1,4-butadiene positively corresponded to the Akron abrasion for the SSBR composites with different brands, and cis-1,4-butadiene could partly replace the influence of vinyl when the content of trans-1,4-butadiene was small. SSBR 2564S, SSBR 4526-2, and SSBR 2535E were selected because of the excellent magic-triangle properties. They were used to investigate the effects of different brands of SSBR with different ratios of natural rubber (NR) to SSBR on the comprehensive properties of the NR–SSBR rubber blend composites. The results indicate that the properties of magic triangle were distinctly enhanced. However, there was an optimized content of SSBR to enhance the wear resistance (≤15 phr). For SSBR 4526-2, the Payne effect was negatively correlated to the content of SSBR, whereas for SSBR 2564S and SSBR 2535E, the Payne effect was positively correlated to the content of SSBR. On the basis of these results, the SSBR 2564S seemed to exhibit the best comprehensive properties to prepare a tire tread tailored for high-performance tires.