Biobased multifunctional ingredients for manufacturing tire treads with high mechanical strength and fuel-saving efficiency

Abstract

Energy-saving and environmental sustainability have driven the tire industry to develop high-performance tires, particularly focusing on high energy efficiency and moving towards sustainable materials. Herein, we report the synthesis of a series of biobased sulfur-rich copolymers (SPs) through the inverse vulcanization of plant oils and sulfur, a significant byproduct from the petroleum industry. These SPs serve as multifunctional ingredients for carbon black (CB)-reinforced rubber composites. Leveraging the reactivity of polysulfide segments towards the rubber chain and polycondensed aromatic moieties of CBs as well as the affinity of the functional groups for the oxygenic groups on the CB surface, the biobased SPs act as both reactive plasticizers and interfacial modifiers. Compared to conventional petroleum-based plasticizers, SPs exhibit superior migration resistance and give the resulting composites higher network strength. Meanwhile, incorporation of SPs significantly improves CB dispersion and enhances the interfacial adhesion of SP-based composites, thus leading to high mechanical properties and remarkably decreased hysteresis loss. Especially, the esterified poly(S₃₀-ER₇₀) shows great potential as a multifunctional ingredient for the preparation of high-performance tires; the poly(S₃₀-ER₇₀)-based tread composite demonstrates a 16.5% reduction in rolling resistance, 10.7% improvement in wet traction performance, and 13.4% increase in aging resistance, compared to the traditional aromatic oil (AO)-based composite. Moreover, the presence of the dynamic covalent bond (–S–S–) imparts excellent recyclability to the poly(S₃₀-ER₇₀)-based rubber material.