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What are silicones ? State the uses of silicones. |
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Answer» Solution :Silicones are a GROUP of organosilicon polymers, which have `(R_2SiO)` as a repeating unit. The starting materials for the manufacture of silicones are alkyl or aryl substituted silicon chlorides, `R_nSiCl_((4-n))`, where R is alkyl or aryl group. When methyl CHLORIDE reacts with silicon in the PRESENCE of copper as a catalyst at a temperature 570K various types of methyl substituted chloramine of formula `MeSiCl_3 , Me_2SiCl_2 , Me_3SiCl` with small amount of `Me_4Si` are formed. Hydrolysis of dimethyl dichlorosilane, `(CH_3)_2SiCl_2` followed by condensation polymerization yields straight chain polymers.  Uses : They are used as SEALANT, greases, and electrical insulators and for water proofing of fabrics. Being biocompatible they are also used in surgical and cosmetic plants. |
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