Iron-Catalyzed Depolymerization of Polysiloxanes to Produce Dichlorodimethylsilane, Diacetoxydimethylsilane, or Dimethoxydimethylsilane

Polymers are one of the important pillars of our current society. Besides the great success a matter is the accumulation of huge amounts of end-of-life polymers. Current waste management bases primarily on landfills, thermal recycling, and down-cycling. Noteworthy, only a small part of the end-of-life materials is recycled by depolymerization, means low-molecular weight synthons are created, which can be polymerized to new polymers to close the cycle. Widely used polymers in modern life times are silicones (polysiloxanes). Based on the intrinsic properties the depolymerization is challenging and only a few high temperature or less environmental-friendly processes have been reported. In this regard, we have set up a capable low-temperature protocol for the depolymerization of silicones with acid chlorides, acetic acid, or methanol in the presence of cheap iron salts as precatalysts to yield dichlorodimethylsilane, diacetoxydimethylsilane, or dimethoxydimethylsilane as well-defined products. Notably, dichlorodimethylsilane, diacetoxydimethylsilane, and dimethoxydimethylsilane can be useful starting materials for synthesizing new polymers; overall a recycling is feasible. (c) 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41287.