To distinguish between genuine and fake silicone oil, you must first understand silicone oil and understand its characteristics.
Silicone oil is a polyorganosiloxane with a chain structure of different degrees of polymerization. It is produced by hydrolyzing dimethyldichlorosilane with water to obtain a primary polycondensation ring body. The ring body is cracked and distilled to obtain a low ring body, and then the low ring body is obtained. Mixtures with different degrees of polymerization can be obtained by telomerizing the ring body, head-capping agent and catalyst together. Silicone oil can be obtained by removing low-boiling substances by distillation under reduced pressure.
Silicone oil characteristics: It has excellent heat resistance, electrical insulation, weather resistance, hydrophobicity, physiological inertness and small surface tension. In addition, it also has low viscosity-temperature coefficient and high compression resistance. Some varieties also have Radiation resistant, non-corrosive to metals, non-toxic, etc.
Silicone oil functions: commonly used as high-grade lubricating oil, anti-shock oil, insulating oil, defoaming agent, release agent, polishing agent and vacuum diffusion pump oil.Among various silicone oils, methyl silicone oil is the most widely used and the most important variety of silicone oil, followed by methylphenyl silicone oil.In addition, there are ethyl silicone oil, methylphenyl silicone oil, nitrile silicone oil, etc.Various functional silicone oils and modified silicone oils are mainly used for special purposes.
Distinguish between true and false silicone oil:
1. Observe with your eyes: Fake silicone oil will be turbid, have a strong smell, and have a bad smell;
2. Test with fire: Use a glass rod or iron rod dipped in a small amount of silicone oil and ignite it. What can ignite and emit black smoke is white mineral oil. Pure silicone oil will not burn when ignited by fire, and it is odorless, clear, transparent, and non-toxic. .The flash point of silicone oil is 320 degrees.
3. Freezing point test method: Silicone oil will not freeze at -50 degrees, while fake silicone oil will become turbid or frozen.
Advantages of silicone oil:
1. Excellent shear stability, has the function of absorbing vibration and preventing vibration transmission, and can be used as a vibration damping fluid.
2. Excellent thermal oxidation stability, such as thermal decomposition temperature >300℃, small evaporation loss (150℃, 30 days, evaporation loss is only 2%), oxidation test (200℃, 72h), small changes in viscosity and acid value .
3. Excellent electrical insulation, volume resistance, etc. do not change within the range of normal temperature to 130°C (but the oil cannot contain water).
4. It is a non-toxic oil with low foaming and strong anti-foaming properties. It can be used as a defoaming agent.
5. The viscosity-temperature performance is better among liquid lubricants, and the viscosity changes little over a wide temperature range.Its freezing point is generally less than -50℃, and some are as high as -70℃. When stored for a long time at low temperature, the appearance and viscosity of the oil will not change. It is a base oil that can take into account high temperature, low temperature and wide temperature range.
Disadvantages of silicone oil:
1. Low surface tension (easy to leak from the machine).
2. Gas solubility is large (difficult to design air sealing device).
3. The thermal expansion coefficient of silicone oil is large (which may cause overpressure problems).
4. The lubricity of silicone oil is poor, especially for steel-steel friction pairs.
5. Certain hygroscopicity (after the water content is higher than 100×10-6, the electrical performance drops sharply)
Release time: 05-10-2022