Promoted dispersion of silica and interfacial strength in rubber/silica composites by grafting with oniums

The dispersion of filler and interfacial interaction are crucial in determining the properties of rubber composites. Aiming to improve the dispersion and filler–rubber interaction, we introduce rubber graft bearing oniums in a rubber/silica composite. To fulfill this goal, the graft, which is prepared via thio‐ene click reaction between 1‐methylimidazolium mercaptopropionate (MMP) and the pendent vinyl groups of a solution‐polymerized styrene‐butadiene rubber (SSBR), is introduced into the silica‐filled styrene‐butadiene rubber (SBR) composite. The dispersion of silica and interfacial interaction are improved via hydrogen bonding interaction. Moreover, the graft exhibits catalytic effect toward the silanization, which can improve interfacial interaction in the composites with bis [3‐(triethoxysilyl) propyl] tetrasulfide. With 2 phr of the graft, the tensile modulus (stress at 300% strain) is increased by 18% and the abrasion loss is decreased by 31%. This study opens a new attempt to improve the filler dispersion and filler–rubber interaction in the composites with onium‐bearing polymers. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136 , 48243.