Conversion of Poly(methylhydrosiloxane) Waste to Useful Commodities.

Poly(methylhydrosiloxane) [PMHS, R(OSiMeH)OR] is applied in chemistry as cheap, low-toxic, air and moisture stable reducing reagent. However, along with the desired products significant amounts of silicone waste is produced, since only ~1.7 % of the PMHS is employed for the reduction process. The formation of PMHS-waste reduces the sustainability of such reduction protocols. For instance PMHS can be applied as reagent (a) in the methanolysis to produce molecular hydrogen; (b) in the reduction of sulfoxides to form the corresponding sulfides; (c) in the hydrodeoxygenation of fatty esters to produce hydrocarbons. An option for the treatment of the PMHS-waste can be the application of depolymerization methods to convert it to useful commodities. In more detail, the silicone waste is reacted in a depolymerization reaction with boron trifluoride diethyl etherate (BFOEt) to produce methyltrifluorosilane (MeSiF) and difluoromethylsilane (MeSiFH), which can be interesting building blocks for the silicone industry, overall demonstrating a resource conserving process. Graphical Abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]