Regulating Vulcanization Kinetics with Deep Eutectic Solvents for Developing Greener Processing Technology of Thermoplastic Vulcanizates

Developing eco-friendly technologies for producing recyclable, high-performance thermoplastic vulcanizates (TPVs) is of critical urgency. Herein, four deep eutectic solvents (DESs) synthesized based on accelerator CZ (N-cyclohexyl-2-benzothiazolesulfenamide) were used to replace CZ to promote the vulcanization of natural rubber (NR). The synthesized DESs could reduce vulcanization temperature and improve vulcanization efficiency, and the DES-aided low-temperature vulcanization of NR gums is favorable for preparing high-strength and low-dissipation vulcanizates. Introducing DESs in dynamic vulcanization can shorten processing time by 71% and reduce mechanical energy input by 37% without interfering with the mechanical properties of TPVs formed by cross-linked NR particles dispersed in an ethylene-vinyl acetate copolymer matrix. Moreover, TPVs exhibit excellent resilience at room temperature. This study provides a sustainable approach for TPV processing with enhanced performance and environmental compatibility.