Sustainable green tire tread design: Soybean oil-based coupling agent enhances rubber-silica interfacial interaction

Abstract

Pollutants resulting from tire tread wear have caused significant harm to ecosystems and human health globally.Consequently, the sustainability of tire development has become a critical concern, with the functionalization of bio-based additives playing a pivotal role. In order to realize the multifunctional application of soybean oil in green tires, in this work, soybean oil was grafted with functional groups through the thiol-ene click reaction, and multifunctionalized soybean oil (SO-Si) with silica coupling effect and rubber plasticizing effect was obtained. When SO-Si is incorporated into green tire treads, it forms a coupling bridge between the rubber and silica, promoting uniform dispersion of silica within the rubber matrix. The interaction between rubber and silica was investigated through molecular dynamics simulations. Compared to traditional silane coupling agents, SO-Si is not only bioenvironmentally friendly but also exhibits enhanced interfacial interactions with both silica and rubber, as confirmed by its effects on the Payne, stress softening, and reinforcement behaviors. Exploiting the strong interaction between silica and rubber, the tread rubber material incorporating SO-Si effectively addresses the 'devil's triangle' of tire performance, enhancing wear resistance by 30 %, improving skid resistance by 29 %, and reducing heat generation by 26 %. These findings offer valuable insights into the development of next-generation high-performance, sustainable tire designs and the utilization of multifunctional vegetable oils.