Types of silicone oil

Silicone oil is a kind of polyorganosiloxane which has different degree of polymerization chain structure. 

It is made by dimethyldichlorosilane adding water hydrolyze to obtain initial condensation ring body, the ring body by cracking, distillation to obtain the low ring body, then put the ring body, sealing agent, catalyst together to conduct telomerization will obtain various mixtures which have different degrees of polymerization, by reduced pressure, distillation and remove low boiling composition can be obtained silicone oil.

In the most commonly used silicone oil, all the organic groups are methyl, called methylsilicone oil. Other organic group also can be used to instead of part of methyl group to improve certain performance and make it applied to a variety of different purposes. Other common groups have hydrogen, ethyl, phenyl, chlorophenyl group, trifluoromethyl group and the like. In recent years, organically modified silicone oil has rapid development, show up a number of organically modified silicone oil which has special properties.

Silicone oil is generally colorless (or pale yellow), odorless, non-toxic, non-volatile liquid. Silicone oil insoluble in water, methanol, glycol and -ethoxyethanol, mutually dissolved 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, low freezing point. To obtain low viscosity silicone oil, used the acid clay as catalyst, and conducts telomerization at 180, or the sulfuric acid as catalyst, conducts telomerization at low temperatures, if want to produce high viscosity silicone oil or a viscous material can use alkaline catalyst. According to the chemical structure, the silicone oil series can be divided into methyl silicone oil, ethyl silicone oil, phenyl silicone oil, methyl hydrogen-containing silicone oil, methylphenyl silicone oil, methyl chlorophenyl silicone oil, methyl ethoxy silicone oil, methyl propyl silicone oil, methyl vinyl silicone oil, methyl hydroxyl silicone oil, ethyl hydrogen-containing silicone oil, hydroxyl hydrogen-containing silicone oil, cyanogen-containing silicone oil and so on. From the applications of view, it has damped silicone oil, diffusion pump silicone oil, hydraulic oil, insulating oil, heat transfer oil, brake oil, etc.

Silicone oil has excellent heat resistance, electrical insulation, weather resistance, hydrophobicity, physiologically inert and smaller surface tension. In addition, it also has a low viscosity-temperature coefficient, high compression resistance, some of the various have the radiation-resistance performance.

The main chain of dimethylsilicone oil is composed by silicone atoms, pendant group which attached to silicon are methyl. Viscosity range is 10 ~ 200000mm2/s at 25. Silicone oil is colorless, transparent, non-toxic and odorless oil, which has excellent electrical insulation properties and heat resistance, high flash point, low freezing point, can be long-term used in the temperature range of -50 ~ +200. Silicone oil has small viscosity-temperature coefficient, big compression ratio, small surface tension, good water-repellent moisture resistance, small specific heat capacity and thermal conductivity. It can be prepared by dimethyl cyclosiloxanes and hexamethyldisiloxane conducted telomerization under the presence of catalysts. Its viscosity was increased by the number of silicone chain sections n in the molecule, from the easily flowing liquid to a thick semi-solid. Has excellent electrical insulating properties and heat resistance.

Used as a long-term release agent in the contour machining of plastic and rubber as well as in food production. It is also used as high and low temperature lubricant between various materials, manufacturing the additives of lubricating plastics. Glass, ceramics, metal, cement and other products which treated with dimethylsilicone oil are not only hydrophobic, but also corrosion resistance, mildew proof, surface smooth. Widely used as heat carrier and efficient defoamers in the chemical, pharmaceutical, cosmetics material, food and other sectors; used as quakeproof damping material in precision machinery and instrumentation; used as high-temperature resistance dielectric liquid in the electric appliance and electronics industry. It also widely used as polishing agent of automotive, furniture, floor, as well as hydraulic oil of pumps, brakes, cylinders and so on.

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