Researchers at the University of North Carolina at Chapel Hill created a new chemical method that converts waste rubber materials, including used tires, into useful epoxy resin precursors. Dr. Aleksandr Zhukhovitskiy leads an innovative approach that solves the worldwide rubber waste problem at scale.
The durable cross-linked polymer structure of rubber makes recycling challenging because it is essential for tire production. The existing devulcanization and polymer backbone cleavage techniques result in material degradation or produce worthless byproducts. The researchers stated that both methods lack effective and scalable solutions for transforming rubber waste.
The two-step process achieves rubber breakdown by applying C–H amination followed by a polymer rearrangement to convert complex structures into amine-functionalized soluble materials. The complete degradation of used rubber occurred within six hours through this method to produce materials that could be used in high-strength epoxy resin manufacturing for coatings, adhesives, and composites.
The discovery presents the opportunity to decrease landfill waste through its application to the more than 274 million discarded tires in the United States during 2021. This method surpasses pyrolysis by running under safer and more affordable conditions between 95-122°F while avoiding the release of harmful substances such as benzene and dioxins.
A sulfur diimide reagent enables the placement of precise amine groups in polymer chains, which then causes backbone rearrangement to break down the material efficiently. The co-author Maxim Ratushnyy described the process as “fascinating because organic transformations work powerfully to convert hard-to-break rubber polymers into valuable epoxy precursors.”
The team works to enhance the process sustainability through investigations of environmentally friendly solvent systems. The research team developed a new approach to turn discarded rubber waste into valuable materials and decrease landfills while protecting the environment, according to Sydney Towell, who co-authored the study.
