Toughening Recycled Waste Rubbers by Dynamic Interactions for Stress Deconcentration

Recycling of waste rubber (WR) is crucial for the sustainable development of the rubber industry. The enhancement of interfacial interactions is the main strategy for waste polymer recycling. However, there is a lack of methods for enhancing the interfacial interactions for WR recycling because WR contains abundant inert C—H bonds. Herein, we designed thioctic acid inverse vulcanization copolymers to endow recycled WR with dynamic disulfide interfacial interactions, significantly improving the mechanical properties of recycled WR. These disulfide interfacial interactions among the recycled WR tend to exchange, which dramatically increases the fractocohesive length and prevents stress concentration near the crack tips. When recycled WR is subjected to external stress, the loads are redistributed across a broad region of adjacent regions instead of being concentrated on a limited length scale, which resists crack propagation. This work effectively recycled WR, providing a strategy for solvent-free reaction-derived inverse vulcanization copolymers to improve the toughness of WR recycling.