New method to convert elemental silicon to usable chlorosilane
The broad spectrum of applications for silicones ranges from medical implants and cosmetics to hydraulic oils and sealants to corrosion protection. To optimize silicon-based synthetic materials for specific applications, madeto-measure chlorosilane building blocks are required in order to produce and crosslink the longchain polymers. This influences the material’s viscosity and flow properties.
Conventionally, the MüllerRochow Direct Process has formed the backbone of the silicone industry. In this process, elementary silicon is converted with methyl chloride into methyl chloro si lanes at high temperatures and pressures in the presence of a copper catalyst. Researchers have now developed a complementary process that has several advantages over the Direct Process: It uses hex a ch lo rodi si lane and chlorinated hydrocarbons as starting materials and works under room temperature and normal pressure. To activate it, just a small concentration of chloride ions is needed in place of a catalyst.
The chemists believe that the chlorosilane monomers formed by this method are special and their potential lays in the fact that they contain not only silicon-chlorine bonds but also carbon-carbon multiple bonds. The purpose of the former is to construct the inorganic silicon-oxygen chains; the latter can be linked to form organic polymers. This unique combination permits new routes to inorganic-organic hybrid materials.