Integrating Multiple Functional Moieties toward Environmentally Friendly and Highly Efficient Interfacial Mediator for Rubber/Silica Composites

Abstract

The problems of high volatile organic compound (VOC) emission and low efficiency of silane coupling agents (SCAs) used in the rubber/silica composites for “green tires” have been troubling the rubber industry. A unique silane (MFSi) integrating hydroxyls, tertiary nitrogen, and norbornenyl were prepared by a solvent-free/catalyst-free one-pot method. MFSi can graft onto the rubber chain through a highly efficient norbornenyl/sulfur reaction, while the dangling hydroxyls in MFSi can improve its affinity with silica and tertiary nitrogen has a significant internal catalytic effect on the silanization of silica. As a result, MFSi shows a significantly higher coupling efficiency of silica-filled composites compared to the most widely used SCAs. Consequently, MFSi-modified composites exhibit excellent environmental friendliness, including significantly reduced heat buildup (∼55%) and abrasion loss (∼53%) and VOC emissions (∼42%). We envision that the design of the multifunctional mediator will provide valuable insights into the development of high-performance “green tires” in a more environmentally friendly manner.