Effect of Modified Ground Tire Rubber on Mechanical and Tribological Properties of Recycled Rubber Under Thermal‐Oxidative Aging: Experiments and Molecular Dynamics Simulations

ABSTRACT Thermo‐oxidative aging is the primary degradation pathway governing the service life and reliability of recycled rubber, as it impairs mechanical properties and limits reutilization. Combined experimental and molecular dynamics (MD) simulations were employed to examine the microstructural evolution and mechanical response of styrene‐butadiene rubber (SBR) and ground tire rubber (GTR) during the thermo‐oxidative aging process. Furthermore, the influence of various modified GTRs on the performance of recycled rubber was also investigated. Accelerated aging at 100°C led to a decrease in tensile strength and elongation at break, accompanied by an increase in hardness. Acid oxidation and incorporation of nanomaterials effectively improved the mechanical and friction properties of aged recycled rubber. Notably, composites containing graphene oxide demonstrated superior performance compared to those with hydroxylated carbon nanotubes, showing a 3.38% enhancement in elastic modulus and a 14.19% reduction in the coefficient of friction. MD simulations were employed to elucidate the influence of thermo‐oxidative aging on the tensile and frictional properties of recycled rubber, and the calculated results were found to be in good agreement with the experimental observations. This work establishes a quantitative oxidation–property nexus for recycled rubber and provides design guidelines for sustainable, aging‐resistant elastomers.