Gallium-catalyzed Boron-assisted Recycling of Any Silicone Waste: Depolymerization to produce Chlorosilanes as key industrial commodities

Chemical recycling back to monomers is a key strategy for a sustainable circular polymer economy. Silicone polymers and networks are wonder hybrid materials with a robust inorganic backbone and tunable organic substituents tailored for various daily life applications. However, their recycling, including mechanical and chemical processes, remains at its infancy. We present a generalized method to depolymerize, at ambient temperatures, any silicone waste; including a very wide range of silicone-based materials and post-consumer waste a.k.a. end-of-life crosslinked polydimethysiloxane-based networks within formulated materials. The reaction harnesses an efficient gallium catalyst, with a 30-million-fold rate enhancement, and boron trichloride as source of chloride to produce nearly quantitative yields of (methyl)chlorosilanes a.k.a. key intermediates from the Müller-Rochow process, at the cornerstone of the Si industry.