Burning behaviors of selected chlorosilanes and SiH-containing siloxanes

摘要

Chlorosilanes are silanes containing the Si-Cl functional group and SiH-containing siloxanes are siloxanes containing the Si-H functional group. Some chlorosilanes and SiH-containing siloxanes present potentially high fire or explosion hazards during handling, storage, transport and process operations. Cone calorimeter tests have been used to study the burning behaviors of selected chlorosilanes and SiH-containing siloxanes at various incident heat fluxes to simulate pool fire burning. The peak heat release rate of a silicon intermediate obtained from the cone calorimeter at 15 kW/m~2 incident heat flux was very close to that measured by a relatively large-scale field test. The flammability of monochlorosilanes was similar to that of organic hydrocarbons having comparable volatility. The flammability of chlorosilanes descends in the order of monochlorosilanes, dichlorosilanes and trichlorosilanes. SiH-containing siloxanes ignited faster than non-SiH-containing siloxanes because of the reactive silicon-hydrogen linkages. The ignition of SiH-containing siloxanes was much more violent than the ignition of non-SiH-containing siloxanes. The SiH-containing siloxanes exhibited a lower peak heat release rate, less total heat released and a lower peak smoke extinction coefficient compared with non-SiH-containing siloxanes having comparable volatility.