Mechanically Robust and Recyclable Styrene–Butadiene Rubber Realized by Ion Cluster Dynamic Cross-Link

Styrene–butadiene rubber (SBR), a widely employed synthetic elastomer, has found diverse applications, including transportation, sealing, and conveyor belts. Nevertheless, the conventional covalent cross-linking network inherently restricts its recyclability and reprocessability, leading to substantial resource depletion and considerable environmental degradation. Herein, we present an efficient strategy for the fabrication of high-performance and recyclable SBR materials based on ionic cluster interactions. The commercial SBR is brominated to establish dynamic ionic cluster cross-linking networks with 4-(alkylamino)-pyridine (DMAP) under simple hot pressing condition. Owing to the electron-donating characteristics and resonance-induced isomerization of DMAP, the SBR obtained in this study attains a markedly elevated tensile strength of 12.0 MPa and a toughness of 48.9 MJ/m3, both of which outperform those of conventional sulfur-vulcanized SBR. Furthermore, the developed SBR materials exhibit outstanding reprocessability due to their effective reversibility of dynamic bromine-DMAP ionic cluster cross-linking, endowing the rubber materials with good recyclability. This study proposes an effective methodology for the fabrication of high-performance, recyclable elastomeric materials, paving a promising path for the sustainable advancement of the rubber industry.