Physicochemical properties of silicone oil

Melting point: -50℃
Boiling point: 101 °C (lit.)
Refractive index: 1.403-1.406
Flash point: 300℃
Density: 0.963
Water solubility: PRACTICALLY INSOLUBLE
Expansion coefficient (25-100℃): 9.45*10-4 silicone oil

Silicone oil is generally colorless (or light yellow), odorless, non-toxic, and non-volatile liquid. Silicone oil is insoluble in water, methanol, glycol and -ethoxyethanol, miscible with benzene, dimethyl ether, methyl ethyl ketone, carbon tetrachloride or kerosene, slightly soluble in acetone, dioxane, ethanol and butanol . It has a small vapor pressure, high flash point and ignition point, and low freezing point. As the number of segments n is different, the molecular weight increases and the viscosity increases, so this silicone oil can have various viscosities, from 0.65 centistokes to millions of centistokes.

If low-viscosity silicone oil is to be prepared, acid clay can be used as a catalyst for telomerization at a temperature of 180°C, or sulfuric acid is used as a catalyst for telomerization at low temperature to produce high-viscosity silicone oil or viscous material with alkaline catalyst.

Silicone oil has excellent heat resistance, electrical insulation, weather resistance, hydrophobicity, physiological inertness and small surface tension, in addition to low viscosity-temperature coefficient, high compression resistance, and some varieties also have radiation resistance performance.