New Chemical Method Transforms Tire Waste into Valuable Epoxy Resins

Millions of tires end up in landfills annually, posing significant environmental challenges. A recent U.S. Department of Energy-funded study at UNC-Chapel Hill introduces a novel chemical method to break down rubber waste into valuable epoxy resin precursors. Led by Dr. Aleksandr Zhukhovitskiy, the research utilizes C-H amination and polymer rearrangement to transform discarded rubber, offering a sustainable alternative to traditional recycling methods like pyrolysis, which generates harmful byproducts. Rubber's cross-linked polymer structure makes recycling difficult. The new technique employs a sulfur diimide reagent to install amine groups at specific locations in the polymer chains, enabling backbone rearrangement. This process breaks down the rubber into soluble, amine-functionalized materials suitable for epoxy resin production. Tests showed significant molecular weight reduction in model polymers and complete breakdown of used rubber in six hours under mild conditions (35-50°C) in aqueous media. This method is more environmentally friendly and cost-effective than traditional techniques. The resulting epoxy resins exhibit strength comparable to commercial resins, offering a potential replacement for petroleum-based chemicals. Researchers are working to optimize the process further by exploring greener solvent systems to reduce waste generation and improve sustainability.