Basic Characteristics and Uses of Methyl Silicone Oil

Methyl silicone oil is generally a colorless, odorless, non-toxic, non-volatile liquid, insoluble in water, methanol, ethylene glycol, miscible with benzene, dimethyl ether, carbon tetrachloride or kerosene, etc., slightly soluble in acetone, Dioxane, ethanol and butanol. Methyl silicone oil is a linear polyorganosiloxane with Si-O-Si as the main chain, two methyl groups and trimethylsiloxy groups connected to Si, and it is liquid at room temperature.

1. Methyl silicone oil has good heat resistance

Since the main chain of the silicone oil molecule is composed of -Si-O-Si- bonds, it has a structure similar to that of inorganic polymers, and its bond energy is very high, so it has excellent heat resistance.

2. Methyl silicone oil has good electrical insulation

Silicone oil has good dielectric properties, and its electrical characteristics change little with the change of temperature and cycle number. The dielectric constant decreases with increasing temperature, but only slightly. The power factor of silicone oil is low and increases with temperature, but it does not change regularly with frequency. Volume resistivity decreases with increasing temperature.

3. Methyl silicone oil has good hydrophobicity

Although the main chain of silicone oil is composed of polar bonds Si-O, the non-polar alkyl groups on the side chains are oriented outwards, preventing water molecules from entering the interior and acting as hydrophobic. The interfacial tension of methyl silicone oil to water is about 42 dynes/cm. When it spreads on the glass, due to the water repellency of silicone oil, it forms a contact angle of about 103°, which is comparable to paraffin wax.

4. The viscosity-temperature coefficient of methyl silicone oil is small

The viscosity of silicone oil is low and changes little with temperature, which is related to the helical structure of silicone oil molecules. Liquid silicone oil is a type of oil with the best viscosity-temperature characteristics among various liquid lubricants. This characteristic of silicone oil is very meaningful for damping equipment.

5. High compression resistance of methyl silicone oil

Due to the helical structure of silicone oil molecules and the large distance between molecules, it has high compression resistance. Utilizing this characteristic of silicone oil, it can be used as a liquid spring, and compared with a mechanical spring, the volume can be greatly reduced.

6. Low surface tension of methyl silicone oil

Low surface tension is a characteristic of silicone oils. Low surface tension means high surface activity. Therefore, methyl silicone oil has excellent defoaming and antifoaming properties, isolation properties from other substances and lubricating properties.

7. Methyl silicone oil is non-toxic, odorless and physiologically inert

From a physiological point of view, silicone polymers are among the most inactive compounds known. Simethicone is inert to organisms and has no rejection reaction with animal organisms. Therefore, they have been widely used in departments such as surgery and internal medicine, medicine, food and cosmetics.

8. Methyl silicone oil has good lubricity

Compared with hydroxy silicone oil, Methyl silicone oil has many excellent properties as a lubricant, such as high flash point, low freezing point, thermal stability, small change in viscosity with temperature, no corrosion of metals, no adverse effects on rubber, plastics, paints, organic paint films, and low surface tension. Easy to spread on the metal surface and other characteristics. In order to improve the lubricity of silicone oil to steel, a lubricity additive that can be miscible in silicone oil can be added. Introducing chlorophenyl into the siloxane chain or replacing dimethyl with trifluoropropylmethyl can greatly improve the lubricating properties of silicone oil.