We are investigating the devulcanization of crosslinked rubber as a sustainable method for reclaiming used car tires. Tire rubbers are among the largest sources of waste polymers in the world as their crosslinked structure and the presence of stabilizers result in their resistance to decomposition. With the rise in car ownership in India, continuous generation of used car tires presents sustainable disposal problems. Common practices of open burning recover some of the tire’s value from its energy-rich hydrocarbon chains, but in the absence of effective and enforced emission controls, these practices can cause substantial ecological damage and health hazards.
The objective of this research is to develop a tire reclamation strategy to convert the waste to a high-value material through a chemical process that breaks the crosslinking sulfide bonds without large effects on the main chain. This process is envisioned to revert the rubber’s structure and characteristics back to those of liquid virgin rubber, thus allowing it to be reformulated into new tires. The re-blending also reduces the amount of raw material needed in tire manufacturer, a proposition that is both environmentally and economically attractive.
Currently, our research focus is on developing a fundamental understanding of the changes occurring in the microstructure and chemistry of rubber after chemical devulcanization, which would allow us to design a treatment process that ensures the retention of performance and physical properties in tires containing recycled material.