TESPT ‐Assisted Devulcanization and Functionalization of Ground Tyre Rubber for Sustainable Rubber Compounds

ABSTRACT Discarded rubber products pose a significant environmental challenge due to their non‐biodegradability and difficulty in recycling. Devulcanization stands out as the most promising technique for recycling rubber waste, transforming thermosetting rubber into a thermoplastic‐like material that retains many of the characteristics of original rubber. Waste tyre rubber is particularly valuable for recovery or regeneration due to its high hydrocarbon content. This study explores the mechano‐chemical devulcanization of ground tyre rubber (GTR) using bis(3‐triethoxysilylpropyl)tetrasulfide, followed by its incorporation into silica‐filled natural rubber (NR) compounds at varying proportions (20–60 wt%) to assess its potential for product applications. A 30% replacement of fresh NR with devulcanized GTR (r‐GTR) significantly enhanced the mechanical performance and thermal behaviour of the green composite compared to the control formulation without r‐GTR. The performance evaluation clearly demonstrates that tensile strength is increased by 153% and T _max improved by 7°C for r‐GTR(30) with respect to r‐GTR(0). Scanning electron microscopy (SEM) images showed that silica filler was evenly distributed throughout the green composite, despite the absence of a coupling agent. Glass transition temperature (T _g ) measurements obtained via dynamic mechanical analysis (DMA) and molecular dynamics simulation showed strong correlation, with the simulated values closely matching the experimental data and relative deviations remaining below 1.63%. The enhanced silica–rubber interaction with r‐GTR content improves silica dispersion in the NR/r‐GTR/SiO ₂ composite, ultimately lowering the rolling resistance of the composites.