Effects of Alkalinity of Ionic Liquid on Catalyzed Silanization in Rubber/Silica Composites

The silane coupling agent has been used for ages to improve the performance of silica-filled rubber composites. To improve the degree of silanization of silica, ionic liquids (ILs) as a catalyst are incorporated to the styrene-butadiene rubber/silica composites. The reaction between bis[3-(triethoxysilyl)propyl]tetrasulfide and silica with different basic ILs is investigated. The results show that the ILs with stronger alkalinity exhibit higher catalytic efficiency. The silanization occurs at lower temperature with the incorporation of ILs. The parameters characterizing interfacial interactions show that the interfacial adhesion is gradually improved with increasing alkalinity of ILs. Consequently, the resulting composite with ILs possessing strong alkalinity exhibits excellent whole performance compared with the composites without ILs. Especially, the energy loss of the rubber wheel in the rolling process is gradually decreased. The composites exhibit excellent abrasion resistance and heat build-up.