Mechanically Accelerated Chemical Deconstruction for Nondeteriorative Recycling of Industrial Unsaturated Thermosets and Rubbers

The deconstruction and recycling of polymers are essential for addressing the ever-growing challenges of waste accumulation and environmental pollution. Carbon–carbon double bond containing polymer networks, ranging from rubbers to plastics, with an annual production exceeding 30 million tons, present a substantial challenge for chemical deconstruction and recycling due to their permanent cross-linked structures. Herein, we present a mechanochemical platform combining physical fragmentation with olefin metathesis to efficiently deconstruct various industrial unsaturated thermosets and rubbers. This approach overcomes network stability limitations by enabling the rapid and complete deconstruction of polymer networks through Ru-catalyzed metathesis reactions using commercially available α-olefins as chain transfer agents. Furthermore, using the industrial thermosets (e.g., polydicyclopentadiene) as a model system, we demonstrate that the deconstructed oligomers enable closed-loop recycling, yielding recycled thermosets with preserved mechanical and thermal properties. Additionally, functionalized olefin chain transfer agents allow for the upcycling of deconstructed products into value-added materials, such as strong adhesives. This work not only provides an efficient approach for deconstructing highly cross-linked polymer networks but also offers a solution for addressing the polymer waste and environmental pollution problems.