Diene Rubber Functionalization and Degradation for Improved Materials Circularity

Diene rubbers are homo- or copolymers containing carbon-carbon double bonds in their repeat units. This unsaturation makes them attractive substrates for various postpolymerization transformations, most notably vulcanization. However, materials such as vulcanized rubber pose a major sustainability challenge in the modern era because current end-of-life pathways often generate significant pollution. As a result, recent research efforts have shifted toward designing more sustainable rubber materials and developing chemical approaches to manage waste. This review highlights recent advances in postpolymerization functionalization of diene rubbers and illustrates how such transformations can be leveraged to enable controlled degradation, recycling, and upcycling. Emphasis is placed on strategies that leverage rubber chemistry to improve performance, enhance circularity, and recover high-value materials from waste feedstocks.