Properties :-
1. They can be used in temperature range of -90 0C to 220 0C
2. They have excellent dielectric properties over a wide range of temperature
3. They have high heat stability & good oxidation resistance
4. They are non corrosive to metals up to 200 0C, fire proof .non toxic, chemically inert & odourless
5. They have excellent water repellency
6. Their viscosity does not change readily with the change in temperature.
7. They are chemically inert.
8. They are non-greasy, non-irritating and odourless.
9. They have tendency to break down and give considerable amounts of gases (H2) and residue which mainly contains carbon, silicon, carbide and SiO2. Beacause of this drawback silicone fluids are not suitable to be used as switchgear oils.
Uses:- 1) As a lubricant: excellent lubrication for plastic and elastomeric surfaces. 2) In polishes and chemical specialities: It is used in automobile and furniture polishes due to its high gloss and water repellency. 3) As a mechanical fluid: It is used as hydraulic or transformer oils, damping mediums. 4) As coolant: They are used as coolant in radio, pulse and aircraft transformers. 5) As a foam preventive: effectively control foam in many machines like photocopiers and laser printers. 6) Also used in cosmetic and pharmaceutical industries. 7) In electrical and chemical specialities: Used as an insulator in medium and high voltage applications i.e. in transformers. 8) As a release material: an odourless, non-toxic, noncarbonizing moulds release for rubber, plastics and metal die castings.