What are the application fields, advantages and disadvantages of silicone oil?            Silicone oil is widely used. It is not only used as special materials in aviation, cutting-edge technology and military technology sectors, but also used in various sectors of the national economy. Its application range has been expanded to: construction, electronics and electricity, textile, automobile, machinery, leather and paper making, chemical light industry, metal and paint, medicine and medical treatment, etc.            The main applications of silicone oil and its derivatives are: film remover, damping oil, dielectric oil, hydraulic oil, heat transfer oil, diffusion pump oil, defoamer, lubricant, hydrophobic agent, paint additive, polishing agent, cosmetics and daily necessities additive, surfactant, particle and fiber treatment agent, silicone grease, flocculant. Silicone rubber is divided into room temperature vulcanized silicone rubber and high temperature vulcanized silicone rubber. The former is mainly used in: sealant, adhesive, conformal coating, gasket, foam rubber, molded parts, packaging materials, electrical insulation, glass assembly, medical implants, surgical auxiliary materials, molding materials; the latter is mainly used in: pipe and hose, tape, wire and cable insulation materials, surgical auxiliary materials, fire-retardant rubber parts, penetration sealing materials , molded parts, embossed roller, automobile ignition cable and spark plug cover, extruded parts, medical implants, laminated products, conductive rubber, fiber coating, foam rubber.            Advantages of silicone oil            (1) Viscosity temperature performance is the best of liquid lubricants, and viscosity changes little in a wide temperature range. Its freezing point is generally less than - 50 ℃, some of which are as high as - 70 ℃, and it is stored for a long time at low temperature. Its appearance and viscosity have no change. It is a base oil with consideration of high temperature, low temperature and wide temperature range.            (2) Excellent thermal oxidation stability, such as thermal decomposition temperature > 300 ℃, little evaporation loss (150 ℃, 30 days, evaporation loss is only 2%), oxidation test (200 ℃, 72h), little change in viscosity and acid value.            (3) The excellent electrical insulation and volume resistance do not change in the range of normal temperature to 130 ℃ (but the oil cannot contain water).            (4) It is a nontoxic oil with low foaming property and strong antifoaming property, which can be used as defoamer, etc.            (5) It has the function of absorbing vibration and preventing vibration transmission. It can be used as damping fluid.            Disadvantages of silicone oil            (1) The lubricity of silicon oil is poor, especially for steel friction pairs.            (2) The thermal expansion coefficient of silicone oil is large (overpressure may occur).            (3) Gas solubility is large (difficult to design gas seal device).