Basic properties and uses of methyl silicone oil!
Polydimethylsiloxane
What is methyl silicone oil: Methyl silicone oil is generally colorless, odorless, non-toxic, non-volatile liquid, insoluble in water, methanol, ethylene glycol, and can be mutually soluble with benzene, dimethyl ether, carbon tetrachloride or kerosene, slightly soluble in acetone, dioxane, ethanol and butanol. Methyl silicone oil is a linear polyorganosiloxane with Si-O-Si as the main chain, 2 methyl groups attached to Si, and trimethylsiloxane capped, which is liquid at room temperature, and its structural formula is as follows:
Product characteristics
1 Good heat resistance
Silicone oil molecule has excellent heat resistance because the main chain is composed of -Si-O-Si-bonds, with a structure similar to that of inorganic macromolecules, and its bonding energy is very high.
2 Good oxidation stability and weathering resistance
3 Good electrical insulation
Silicone oil has good dielectric properties, with the temperature and the number of waves, its electrical properties change very little. The dielectric constant decreases with increasing temperature, but the change is very small. The power factor of silicone oil is low and increases with temperature rise, but there is no rule with frequency change. Volume resistivity decreases with rise in temperature.
4 Good hydrophobicity
Although the main chain of silicone oil consists of polar bonds Si-O, but because of the side chain of the non-polar base alkyl toward the outside of the directional arrangement, preventing water molecules from entering the interior, hydrophobic effect. Silicone oil on the interfacial tension of water is about 42 dynes / cm, when diffused on top of the glass, due to the water repellency of silicone oil, the formation of about 103 ° contact angle, comparable to paraffin.
5 Viscosity and temperature coefficient is small
Silicone oil viscosity is low, and with the temperature change is small, which is related to the spiral structure of the silicone oil molecule. Silicone oil is a variety of liquid lubricants with the best viscosity-temperature characteristics of a class of oils, silicone oil of this characteristic is very meaningful to the damping equipment.
6 High compression resistance
Due to the helical structure of the silicone oil molecules and the intermolecular distance is large, so it has a high resistance to compression. By utilizing this characteristic of silicone oil, it can be used as a liquid spring, and compared with mechanical springs, the volume can be greatly reduced.
7 Low surface tension
Low surface tension is a characteristic of silicone oil. Low surface tension indicates high surface activity, so silicone oils have excellent anti-foaming and anti-foaming properties, isolation from other substances, and lubricating properties.
8 Non-toxic, odorless and physiologically inert
From a physiological point of view, silicone polymers are among the most inactive compounds known. Dimethicones are biologically inert and have no rejection with the animal organism. Therefore, they have been widely used in sectors such as surgery and internal medicine, pharmaceuticals, food and cosmetics.
9 Good lubrication
Silicone oil has many excellent properties as a lubricant, such as high flash point, low freezing point, heat stability, viscosity with temperature change is small, does not corrode the metal as well as rubber, plastic, paint, organic paint film has no adverse effects and low surface tension, easy to spread on the metal surface and other characteristics. In order to improve the steel-to-steel lubricity of silicone oil, can be added to the lubricity additives that can be miscible with silicone oil. The lubricity of silicone oil can be greatly improved by introducing chlorophenyl group on the silicone chain or replacing dimethyl with trifluoropropyl methyl.
