Development of Activated Micronized Crumb Rubber by Physical Modification for Enhanced Usage in Tire Compound Formulations

ABSTRACT The limited compatibility of micronized rubber crumb (MRC) with virgin elastomers remains a major challenge for its large‐scale use in tire compounds. In this study, we explored a facile physical activation method using solvent treatment to improve the surface characteristics and interfacial behavior of MRC in natural rubber (NR) and solution styrene–butadiene rubber (SSBR) matrices. The crumb was treated with toluene and acetone and dried under vacuum. The enhanced surface roughness generation was obtained particularly for the toluene‐treated crumb, which was incorporated into rubber compounds at different loadings, by partially replacing N330 of the control recipe. The modified crumb lowered the tan δ at 60°C, implying better processability and reduced rolling resistance as compared to the control compound. Mechanical properties and hardness were largely retained, and aging resistance improved, especially in the SSBR‐based compounds. In general, the results demonstrate that solvent‐assisted physical modification provides a practical, scalable route to incorporate higher recycled rubber content into tire compounds without compromising essential properties.