Effects of antioxidant functionalized silica on reinforcement and anti-aging for solution-polymerized styrene butadiene rubber: Experimental and molecular simulation study

Highlights: • A novel antioxidant functionalized silica (SiO₂-g-MC) was prepared by grafting antioxidant MC onto the silica surface. • The filler SiO₂-g-MC greatly improved the mechanical properties and aging resistance of SSBR composite. • The effects of SiO₂-g-MC on reinforcement and anti-aging for SSBR were explained via molecular simulation methods. A new type of antioxidant functionalized silica (SiO₂-g-MC) was prepared by grafting antioxidant N-(4-aniline phenyl) maleic imide (MC) onto the surface of silica via γ-mercaptopropyl trimethoxysilane (KH590). The effects of SiO₂-g-MC on reinforcement and anti-aging for solution-polymerized styrene butadiene rubber (SSBR) were investigated by experimental and molecular simulation methods. It was found that the reinforcement of SiO₂-g-MC was much more effective than that of the neat silica (SiO₂) in SSBR matrix due to well-dispersion and strong interfacial interaction between SiO₂-g-MC and SSBR. Compared with KH590 modified silica (SiO₂-KH590) and SiO₂, SiO₂-g-MC had better vulcanization behavior and could greatly improve thermo-oxidation resistance of SSBR composite. Furthermore, grafting MC onto the surface of silica could not only restrain the migration of free MC, but also reduce the negative influence of free MC on cross-linking density of SSBR composite. Therefore, SiO₂-g-MC/SSBR composite exhibited more preeminent mechanical properties than SiO₂-KH590/MC/SSBR composites during the thermo-oxidation aging process. These results indicated that SiO₂-g-MC could be used as a functional filler for the preparation of high performance SSBR composites, and moreover, the theoretical molecular simulation process can help us gain a better insight into the structure-property relationship for SSBR composite.