Silicones are the synthetic organois licone polymers which contains Si-O-Si linkages. These are represented by the general formula `(R_(2) SiO)_(x)`, Here R may be alkyl or phenyl group. In general, silicones are formed by reacting Grignar reagent with `SiCl_(4)` and this is followed to hydrolysis. (i) How are linear silicones formed? (ii) How are cross- linked silicones prepared? (iii) What is the value associated with silicones?

Silicones are the synthetic organois licone polymers which contains Si

1.	Silicones are the synthetic organois licone polymers which contains Si-O-Si linkages. These are represented by the general formula `(R_(2) SiO)_(x)`, Here R may be alkyl or phenyl group. In general, silicones are formed by reacting Grignar reagent with `SiCl_(4)` and this is followed to hydrolysis. (i) How are linear silicones formed? (ii) How are cross- linked silicones prepared? (iii) What is the value associated with silicones?
Answer» (i) Linear silicones are formed by the hydrolysis of dichlorosilances followed by polymerisation. (ii) Cross-linked silicones are formed by the hydrolysis of trichlorosilanes followed by polymerisation. (iii) Silicones have wide range of applications. Silicone-rubbers retain their elasticity over a range of temperature These are used as insulating materials for electrical motorws and other appliances. Silicones are also used inmaking greases that act as lubircants in acroplnaes.

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