Question

How are silicones prepared? Write necessary reaction. Write two uses of silicones.​

Answer 1

Answer:

Sillicones are polymers that are made by atoms of alternate molecules of sillicon and oxygen , frequently combined by carbon and hydrogen.

Sillicones are generally prepared by hydrolysis of dialkyldichlorosillanes(R2SiCl2) or diarychlorosillanes( Ar2SiCl2) which is prepared by passing vapors of RCl or ArCl over Si in the presence of catalyst copper.

Reaction:

2RCl + Si ---------> R2SiCl2

Copper(540 K)

R2SiCl2 -----------> O-Si-O-Si-O-Si-O-HCl

Sillicones can be in form of oil or rubber depending on extent of polymerisation

Answer 2

Answer:

Silicones are polymers that are made by atoms of alternate molecules of silicon and oxygen, frequently combined by carbon and hydrogen.

Silicone are typically heat - resistant and rubber like structure .

Silicones are prepared by the hydrolysis of alkyl or aryl substituted silicon halides. Alkyl or aryl substituted silicon halides are prepared by passing gaseous alkyl or aryl halide over an alloy of copper and silicon at 300degreeC. The hydrolysis of dimethyldichlorosilane gives dimethyl silanol.

Silicones can be in form of oil or rubber depending on extend of polymerization.

hydrolysis of

dialkyldichlorosilanes (R2SiCl2) or

diarychlorosilanes (Ar2SiCl2) which is prepared by passing vapours of RCl or ArCl over Si in the presence of catalyst copper.

REACTIONS

2RCl + Si ----> R2SiCl2

Copper (540 k)

R2SiCl2 ----> O-Si-O-Si-O-Si-O- HCl

USES

Used in sealants, adhesives, lubricants, medicine, cooking utensils, thermal and electronic insulation.