Properties and classification of silicone oil (1)


Definition of silicone oil


Silicone oil is a kind of polysiloxane with different degree of polymerization chain structure. It is made of dimethyldichlorosilane by hydrolysis with water to produce primary polycondensation ring. The ring body is cracked and rectified to produce low ring body. Then the ring body, head sealing agent and catalyst are put together for polycondensation to obtain a variety of mixtures with different degrees of polymerization. After the low boiling matter is removed by vacuum distillation, silicone oil can be produced.






The most commonly used silicone oil, the organic groups are all methyl, called methyl silicone oil. Other organic groups can also be used to replace some methyl groups in order to improve some properties of silicone oil and apply to various purposes. Other common groups are hydrogen, ethyl, phenyl, chlorophenyl, trifluoropropyl, etc. In recent years, organic modified silicone oil has been developed rapidly, and there are many organic modified silicone oil with special properties.


Silicone oil is generally colorless (or light yellow), tasteless, non-toxic, non-volatile liquid. Silicone oil is insoluble in water, methanol, glycol and - ethoxyethanol. It is miscible with benzene, dimethyl ether, methyl ethyl ketone, carbon tetrachloride or kerosene. It is slightly soluble in acetone, dioxane, ethanol and alcohol. It has small vapor pressure, high flash point and ignition point, and low freezing point. With the different number of chain segments n, the molecular weight increases and the viscosity also increases. There are various viscosities for fixing the silicone oil, ranging from 0.65 centistokes to millions of centistokes. If low viscosity silicone oil is to be prepared, acid clay can be used as catalyst and polymerized at 180 ℃, or sulfuric acid can be used as catalyst and polymerized at low temperature to produce high viscosity silicone oil or viscous substance.


Oil classification


According to the chemical structure, silicone oil is divided into methyl silicone oil, ethyl silicone oil, phenyl silicone oil, methyl hydrosilicone oil, methyl phenylsilicone oil, methyl chlorophenyl silicone oil, methyl ethoxy silicone oil, methyl trifluoropyl silicone oil, methyl vinyl silicone oil, methyl hydroxysilicone oil, ethyl hydrosilicone oil, hydroxyhydrosilicone oil, cyanogen silicone oil, etc.; from the purpose, damping silicone oil and diffusion pump silicone oil are available Oil, hydraulic oil, insulating oil, heat transfer oil, brake oil, etc.


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


Transferred from rubber technology studio Li Xiuquan