Summary
A peer-reviewed Nature study reports a chemical method that cleaves silicone’s Si–O–Si backbone and regenerates an industrially relevant dichlorosilane monomer. The approach worked across linear and cyclic siloxanes, including commercial silicone oils and elastomers.
A peer-reviewed study published in Nature on 28 October 2026 reports a method for breaking silicone polymers back down into an industrially relevant dichlorosilane monomer. The researchers use deoxygenative chlorination to cleave the silicon–oxygen–silicon (Si–O–Si) links in siloxanes under mild conditions.
Silicones are used in industrial, medical and consumer products partly because they tolerate heat and resist chemical change. Those same properties make their recycling difficult. The method reported in the study was tested across a range of linear and ring-shaped siloxanes, including commercial silicone oils and elastomers.
Breaking the siloxane backbone
Silicones are polymers whose backbones contain repeating silicon and oxygen atoms, with organic groups attached to silicon. In this study, the researchers target the Si–O–Si links that join those units. Instead of recycling the material only into smaller cyclic siloxanes, the approach aims to return it to a dichlorosilane monomer that can serve as a chemical feedstock.
The reaction uses a silylium ion to initiate the depolymerization. Phosgene and higher substitutes act as deoxygenative chlorinating reagents: they help remove oxygen while chlorine is introduced as the Si–O–Si bond is cleaved. The paper describes the reactions as proceeding under mild conditions, though its abstract does not specify the exact temperatures or other operating parameters.
The reported substrate range includes both linear and cyclic siloxanes. Applying the chemistry to commercial silicone oils and elastomers is significant because it shows the method is not limited to a single specially prepared model compound.
What the mechanism suggests
Mechanistic investigations, supported by computational calculations, point to a more active role for phosgene than simply supplying chloride. The researchers propose that Lewis-acid activation by the silylium ion forms a chlorocarbonyl cation in the reaction mixture, which acts as the species that cleaves the siloxane links.
That proposed pathway helps explain how a chemically robust backbone can be dismantled through a targeted reaction. It also identifies the interaction between the silylium ion and chlorinating reagent as central to the reported chemistry.
A possible feedstock-recycling route
Silicone waste is currently managed through routes including landfill, incineration, mechanical recycling and chemical recycling to cyclic siloxanes. Returning polymers to a monomer offers a different chemical-recycling target: recovering a feedstock rather than producing only smaller siloxane molecules. The authors present the method as a new approach to circular recycling of siloxane materials.
The study reports a chemical strategy and its substrate scope, rather than an established waste-processing system. Its relevance to large-scale recycling will depend on how the chemistry performs in practical processing and material-recovery settings.