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) ( c PC 2 SO), with tunable mechanical properties through a simple one-step process. With two carbon atoms in each repeating unit, PC 2 SO 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, PC 2 SO elastomer can be recovered even from mixed plastic waste and reprocessed into functional silicone materials with tailored properties. These features make PC 2 SO 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.