|
|Section2= |Section6= |Section7= }} Polydimethylsiloxane (PDMS) belongs to a group of polymeric organosilicon compounds that are commonly referred to as silicones.〔("Linear Polydimethylsiloxanes" ) Joint Assessment of Commodity Chemicals, September 1994 (Report No. 26) ISSN 0773-6339-26.〕 PDMS is the most widely used silicon-based organic polymer, and is particularly known for its unusual rheological (or flow) properties. PDMS is optically clear, and, in general, inert, non-toxic, and non-flammable. It is also called dimethicone and is one of several types of silicone oil (polymerized siloxane). Its applications range from contact lenses and medical devices to elastomers; it is also present in shampoos (as dimethicone makes hair shiny and slippery), food (antifoaming agent), caulking, lubricants, kinetic sand , and heat-resistant tiles. ==Structure== The chemical formula for PDMS is CH3()''n''Si(CH3)3, where ''n'' is the number of repeating monomer () units.〔Mark, J. E.; Allcock, H. R.; West, R. “Inorganic Polymers” Prentice Hall, Englewood, NJ: 1992. ISBN 0-13-465881-7.〕 Industrial synthesis can begin from dimethyldichlorosilane and water by the following net reaction: :''n'' Si(CH3)2Cl2 + ''n+1'' H2O → HO()''n'' H + 2''n'' HCl The polymerization reaction evolves hydrogen chloride. For medical and domestic applications, a process was developed in which the chlorine atoms in the silane precursor were replaced with acetate groups. In this case, the polymerization produces acetic acid, which is less chemically aggressive than HCl. As a side-effect, the curing process is also much slower in this case. The acetate is used in consumer applications, such as silicone caulk and adhesives. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Polydimethylsiloxane」の詳細全文を読む スポンサード リンク
|