Silicone oil usually refers to linear polysiloxane products which keep liquid state at room temperature. R is alkyl and aryl, R 'is alkyl, aryl, hydrogen, carbon functional group and polyether chain; X is alkyl, aryl, alkenyl, hydrogen, hydroxyl, alkoxy, acetoxy, chlorov, carbon functional group and polyether chain; n, M = 0, 1, 2, 3            The most commonly used silicone oil, the organic group is all methyl, called methyl silicone oil. Organic groups can also use other organic groups instead of some methyl groups to improve some properties of silicone oil and apply to various uses. Other common groups are hydrogen, ethyl, phenyl, chlorophenyl, trifluoropropyl, etc. In recent years, organic modified silicone oil has been developed rapidly, and many organic modified silicone oil with special properties has appeared.            According to the chemical structure, silicone oil can be 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 containing silicone oil, hydroxyl hydrogen containing silicone oil, and cyanogen containing silicone oil; from the use, there are damping silicone oil and diffusion pump silicon Oil, hydraulic oil, insulating oil, heat transfer oil, brake oil, etc.