Thermo‐Oxidative Decrosslinking of Tire Rubber Accelerated by Fluid Catalytic Cracking Slurry

ABSTRACT The large accumulation of waste tire rubber presents significant environmental and resource‐recovery challenges. Green decrosslinking of tire rubber is the key to upcycling of waste tire rubber. Based on the strong swelling and solvating capability of fluid catalytic cracking (FCC) slurry, thermo‐oxidative decrosslinking behavior of tire rubber promoted by FCC slurry was investigated. The effects of FCC contents, air supply, and rubber particle size on degradation efficiency of tire rubber were evaluated. It was found that FCC significantly enhanced decrosslinking of tire rubber. Incorporation of 25% FCC yielded a sol fraction of 36.26% at 150°C. Air supply was found to play a critical role in oxidation and decrosslinking process; increased air supply resulted in the highest sol fraction (43.54%) at 150°C, while reduced air supply resulted in effective decrosslinking (46.05%) at 180°C. In addition, smaller rubber particle size (50 mesh) exhibited more effective decrosslinking. These findings demonstrated that FCC, characterized by residual catalyst activity along with swelling and solvating effects, offers an efficient and tunable pathway for waste tire rubber valorization, offering valuable insights for the development of sustainable rubber recycling technologies.