Silicone Fluids

Silicone fluids are generally colorless transparent liquids. They exhibit excellent resistance to heat, cold, and moisture. Their viscosity changes little over a wide temperature range, and they have outstanding electrical properties. In addition, they are notable for their characteristics of mold-releasability, water repellency, lubricity, and defoaming properties.

Read more

Features

Heat Resistance

Silicone fluids have outstanding stability against thermal oxidation.

Cold Resistance

Silicone fluids withstand low temperatures well. Methylphenyl silicone fluid, formulated for low-temperature applications, maintains flowability even at -65°C.

Viscosity Stability

There is little change in viscosity over a wide temperature range.

Chemical Stability

Silicone fluids are almost totally chemically inactive. At room temperature, they show almost no effects from alkali solutions (up to 10%) or acidic solutions (up to 30%).

Non-Corrosive and Minimal Impact on Other Materials

Silicone fluids have almost no adverse effects on metals and many other materials.

Low Surface Tension

Silicone fluids have much lower surface tension than water and other common synthetic oils.

Product Search for Personal Care

Typical Products

Any liquid polymerized siloxane with organic side chains

Silicone oil is any liquid polymerized siloxane with organic side chains. The most important member is polydimethylsiloxane. These polymers are of commercial interest because of their relatively high thermal stability and their lubricating properties.

Structure

Like all siloxanes (e.g., hexamethyldisiloxane), the polymer backbone consists of alternating silicon and oxygen atoms (...Si−O−Si−O−Si...). Many groups can be attached to the tetravalent silicon centers, but the dominant substituent is methyl or sometimes phenyl. Many silicone liquids are linear polymers end-capped with trimethylsilyl groups. Other silicone liquids are cyclosiloxanes.

Applications

Silicone oils are primarily used as lubricants, thermic fluid oils, or hydraulic fluids. They are excellent electrical insulators and, unlike their carbon analogues, are non-flammable. Their temperature stability and good heat-transfer characteristics make them widely used in laboratories for heating baths ("oil baths") placed on top of hotplate stirrers, as well as in freeze-dryers as refrigerants. Silicone oil is also commonly used as the working fluid in dashpots, wet-type transformers, diffusion pumps, and in oil-filled heaters. Aerospace use includes the external coolant loop and radiators of the International Space Station Zvezda module, which rejects heat in the vacuum of space.

The class of silicone oils known as cyclosiloxanes has many of the same properties as other non-cyclic siloxane liquids but also has a relatively high volatility, making it useful in a number of cosmetic products such as antiperspirant.

Some silicone oils, such as simethicone, are potent anti-foaming agents due to their low surface tension. They are used in industrial applications such as distillation or fermentation, where excessive amounts of foam can be problematic. They are sometimes added to cooking oils to prevent excessive foaming during deep frying. Silicone oils used as lubricants can be inadvertent defoamers (contaminants) in processes where foam is desired, such as in the manufacture of polyurethane foam.

Silicone oil is also one of the two main ingredients in Silly Putty, along with boric acid.

Silicone oil may be used as a gun lubricant. It is compatible with the rubber, plastic, and metal parts frequently found in firearms. Due to the high surface adhesion of silicone oil, it forms a persistent film which may be useful in protecting guns during extended storage.

Medical Uses

Consumer products to control flatulence often contain silicone oil. Silicone oils have been used as a vitreous fluid substitute to treat difficult cases of retinal detachment, such as those complicated with proliferative vitreoretinopathy, large retinal tears, and penetrating ocular trauma. Additionally, silicone oil is used in general medicine and surgery. Because of silicone oil's water repellent and lubricating properties, it is considered an appropriate material to maintain surgical instruments. They are also used in digital rectal examinations (DRE).

Automotive Use

Silicone oil has been commonly used as the fluid in the automobile cooling fan clutch assemblies and is still being used in the newer electronic fan clutches.

References

For more information, please contact us. We will provide professional answers.