Advancing Green and Sustainable Approaches: Investigating the Impact of Carbohydrates on Silica-Filled Natural Rubber Composites

Abstract

Reducing rolling resistance in heavy-vehicle tyres, such as those used in trucks and buses, is crucial for lowering fuel consumption. Incorporating maximum silica filler into naturally derived elastomers, particularly cis-1,4-polyisoprene (CPI), presents a significant opportunity for the tyre industry to produce environmentally friendly and sustainable tyres with a reduced carbon footprint. However, achieving uniform dispersion of silica filler in CPI is challenging because of the disruption of silanization reactions by non-rubber substances, primarily proteins and phospholipids, present in CPI. This study explores the introduction of various cost-effective carbohydrates (i.e., Arabinose, Sucrose, Sorbitol, and Xylose) into the CPI matrix at different silica filler loadings to mitigate interference during silanization. Among these, the polyol group sugar alcohol, sorbitol, notably enhanced silica dispersion within the CPI matrix. The inclusion of sorbitol not only minimized rolling resistance but also improved processing behavior and significantly enhanced mechanical properties. The use of bio-based sugar alcohols in tyre production holds promise for advancing the development of eco-friendly and sustainable tyres. Molecular dynamics simulations of CPI with these carbohydrates and silica filler demonstrate minimal structural deviation in CPI and maximum network formation, particularly with sorbitol. The findings also confirm strong interactions between CPI's non-rubber components and the OH/CHO groups of the carbohydrates.