Silicone oil is a kind of polyorganosiloxane with chain structure of different polymerization degree. It is made of dimethyl dichlorosilane hydrolyzed with water to get the initial condensation of the cyclobody, the cyclobody after cracking, rectification to get the low cyclobody, and then put the cyclobody, the head agent, catalyst together to get a mixture of different degrees of polymerization, vacuum distillation to remove the low boiling matter can be prepared silicone oil.

The most commonly used silicone oil, organic groups are all methyl, called shen-based silicone oil. Organic groups can also be used to replace some methyl groups with other organic groups to improve certain properties of silicone oil and suitable for various uses. Other common groups are hydrogen, ethyl, phenyl, chlorophenyl, trifluoropropyl, etc. In recent years, organic modified silicone oil has been developed rapidly, many organic modified silicone oil with special properties have appeared.

Silicone oil is generally colorless (or light yellow), tasteless, non-toxic, non-volatile liquid. Silicone oil is insoluble in water, methanol, diol and -ethoxy ethanol, and can be mutually soluble with benzene, dimethyl ether, methyl ethyl ketone, carbon tetrachloride or kerosene, slightly soluble in acetone, dioxane, ethanol and alcohol. It has very small vapor pressure, high flash point and flash point, low freezing point. The molecular weight increases and the viscosity increases with the number of chain segments n. The siloxane can produce a wide range of viscosities from 0.65cm to millions of centistokes. If you want to make low viscosity silicone oil, you can use acid clay as a catalyst, and at 180℃ temperature for polymerization, or use sulfuric acid as a catalyst, at low temperature for polymerization, production of high viscosity silicone oil or viscous substance can be used alkaline catalyst.

According to the chemical structure of silicone oil is divided into methyl silicone oil, ethyl silicone oil, phenyl silicone oil, methyl hydrogen silicone oil, methyl phenyl silicone oil, methyl chlorophenyl silicone oil, methyl ethoxy silicone oil, methyl trifluoropropyl silicone oil, methyl vinyl silicone oil, methyl hydroxyl silicone oil, ethyl hydrogen silicone oil, hydroxyl hydrogen silicone oil, cyanide silicone oil, etc.; From the point of use, there are damping silicone oil, diffusion pump silicone oil, hydraulic oil, insulation oil, heat transfer oil, brake oil and so on.
Silicone oil has excellent heat resistance, electrical insulation, weather resistance, hydrophobicity, physiological inertia and small surface tension, in addition to the low viscosity temperature coefficient, high compressive resistance) some varieties also have radiation resistance.