Effective Thermal-Oxidative Reclamation of Waste Tire Rubbers for Producing High-Performance Rubber Composites

Abstract

The disposal and accumulation of waste tire rubbers has a significant negative impact on the development of a circular economy and sustainable environment. To reuse and recycle ground tire rubber, we developed a thermal-oxidative reclamation process using a newly designed dynamic reclamation reactor. In the absence of any chemical agent, a high scission efficiency was achieved at a sol fraction of 66.53 wt % at 200 °C after 20 min from the thermal oxidation of GTR. The physical and chemical structural evolutions of GTR during the thermo-oxidation process were systemically investigated by monitoring the Mooney viscosity, sol–gel ratio, molecular weight, and chemical structure changes. The reclaimed ground tire rubber containing ultrafine fillers and soluble elastomer can be easily dispersed into a natural rubber matrix. The mechanical properties and aging resistance of the modified natural rubber were enhanced with the addition of up to 40 wt % reclaimed ground tire rubber. This work demonstrates a green and up-scalable approach for reclamation and reuse of waste tire rubbers for a sustainable rubber industry.