Poly(carbosiloxane) Elastomers: One-Step Synthesis, Tunable Mechanics, and Closed-Loop Recyclability

Silicone materials are ubiquitous in products ranging from kitchenware to wearable devices due to their flexibility, low toxicity, and durability. Most silicones are made from cross-linked poly(dimethylsiloxane), making them highly unrecyclable and destined for landfill accumulation. In this study, we introduce a synthetic route for a silicone-based elastomer, cross-linked poly(carbosiloxane) (cPC2SO), with tunable mechanical properties through a simple one-step process. With two carbon atoms in each repeating unit, PC2SO exhibits enhanced softness and stretchability, while having the ability to be selectively deconstructed into a corresponding monomer that can be repolymerized. Owing to its selective depolymerization, PC2SO elastomer can be recovered even from mixed plastic waste and reprocessed into functional silicone materials with tailored properties. These features make PC2SO a practical and sustainable alternative to conventional silicone elastomers. This study establishes a design principle for recyclable silicone networks that integrate mechanical robustness with chemical circularity.