Silicone

Name:
Silicone
Detailed information:

Chemistry name:	organosiloxane
Chemistry structure:
Properties:
Liquids, semisolids, or solids depending on molecular weight and degree of polymerization. Viscosity ranges from less than 1 to more than 1 million centistokes. Polymers may be straight chain, or cross-linked with benzoyl peroxide or other free radical initiator, with or without catalyst. Stable over temperature range from –50 to +250C. Very low surface tension; extreme water repellency; high lubricity; excellent dielectric properties; resistant to oxidation, weathering, and high temperatures; permeable to gases. Soluble in most organic solvents; unhalogenated types are combustible.
Derivation:
(1) Silicon is heated in methyl chloride to yield methylchlorosilanes; these are separated and purified by distillation and the desired compound mixed with water. A polymeric silicone results. (2) Reaction of silicon tetrachloride and a Grignard reagent (RMgCl), with subsequent hydrolysis and polymerization.
Available forms:
Fluids, powders, emulsions, solutions, resins, pastes, elastomers.
Use:
(Liquid) Adhesives, lubricants, protective coatings, coolants, mold release agents, dielectric fluids, heat transfer, wetting agents and surfactants, foam stabilizer for polyurethanes, diffusion pumps, antifoaming agent for liquids, textile finishes, water repellent, weatherproofing concrete, brake fluids, cosmetic items, polishes, foam shields in solar energy collectors, rust preventives. (Resin) Coatings, molding compounds, laminates (with glass cloth), filament winding sealants, room-temperature curing cements, electrical insulation, impregnating electric coils, bonding agent, modifier for alkyd resins, vibration-damping devices. (Elastomer, or silicone rubber) Encapsulation of electronic parts; electrical insulation; gaskets; surgical membranes and implants; automobile engine components; flexible windows for face masks, air locks, etc.; miscellaneous mechanical products.

See Organosilicon.