2025-04-24 フランス国立科学研究センター（CNRS）
＜関連情報＞
- https://www.cnrs.fr/en/press/new-recycling-process-silicones-could-greatly-reduce-sectors-environmental-impacts
- https://www.science.org/doi/10.1126/science.adv0919
三塩化ホウ素を用いたガリウム触媒によるシリコーン廃棄物のリサイクルにより、重要なクロロシランが得られる Gallium-catalyzed recycling of silicone waste with boron trichloride to yield key chlorosilanes
Nam Đức Vũ, Aurélie Boulegue-Mondière, Nicolas Durand, Joséphine Munsch, […], and Jean Raynaud
Science Published:24 Apr 2025
DOI:https://doi.org/10.1126/science.adv0919
Editor’s summary
Recent progress in both mechanical and chemical polymer recycling has largely focused on carbon-based materials. By contrast, methods to break down or repurpose silicones lag far behind, in part because of the often complex cross-linked structures at play. Vũ et al. now report a versatile method to recycle a wide range of silicone materials using the combined action of a gallium catalyst and a boron trichloride reagent (see the Perspective by Ghosh). The reaction produces chlorinated silane monomers that can be straightforwardly reused, as well as a boron oxide co-product that is applicable in the glass industry. —Jake S. Yeston
Abstract
Chemical recycling to monomers is a key strategy for a sustainable circular polymer economy. However, most efforts have focused on polymers with carbon backbones. Recycling of silicone polymers and corresponding materials, featuring a robust inorganic backbone and tunable properties, remains in its infancy. We present a general method for depolymerization of a very wide range of silicone-based materials and postconsumer waste, including end-of-life cross-linked polydimethylsiloxane-based networks within formulated materials. The reaction proceeds at 40°C, harnessing an efficient gallium catalyst for a million-fold rate enhancement and boron trichloride as the chlorine source, to produce nearly quantitative yields of (methyl)chlorosilanes, key intermediates in the Müller-Rochow process that anchors the silicone industry.
