Polydimethylsiloxane (PDMS) CAS 63148-62-9

About Polydimethylsiloxane (PDMS)

Polydimethylsiloxane is built from a flexible silicon-oxygen backbone carrying methyl groups, and the trimethylsiloxy-ended chains form a clear, neutral oil. Short chains give a thin, free-flowing fluid, while longer chains raise the viscosity measured in centistokes at 25 °C, the first specification to confirm when ordering. Across the grades the material keeps the same useful character: water repellent, non-gumming, resistant to heat, cold and oxidation, electrically insulating and suitable for cosmetic and food contact uses. The fluid does not react with most substrates and leaves a thin, uniform film, so it serves as a release layer, lubricant, foam breaker and glossy surface treatment without adding solids.

Applications

PDMS turns up across process industries, personal care and surface care:

• Defoaming and food processing. Breaks and prevents foam in fermentation, beverages, frying oil, paper, textile dyeing, water treatment and chemical processing; food contact grade corresponds to the E900 antifoam.
• Mold release and lubrication. Release film for plastics, rubber and metal die casting, plus quiet, long-lived lubrication for bearings, valves, instruments and food machinery.
• Personal care. Listed as dimethicone in skin and sun care, hair conditioners, antiperspirants and color cosmetics for a silky, non-greasy, water-resistant feel and easy spreading.
• Polishes, coatings, textiles and electronics. Gloss and protection in car, furniture, leather and tire polishes; leveling and slip in paints and inks; softness and water repellency on fabric; dielectric and damping use in electrical and instrument work.

Specifications

PDMS is offered as a series of viscosity grades rather than one fixed assay, and UATChem matches the cSt value at 25 °C to the way the fluid is applied: low viscosities wet and spread quickly, medium grades balance film and handling, and high viscosities stay in place for damping and heavy polish. Industrial, cosmetic dimethicone and food contact grades are available, and each lot is released with appearance, viscosity, density, volatility and nonvolatile content reported on the COA, with the full grade table on the TDS. The fluid is water insoluble and should be dispersed or emulsified for water-based formulas.

Typical profile; grade and viscosity confirmed to the application, and the batch COA governs.

Packaging and Storage

The fluid ships in 200 kg blue steel drums and 1000 kg IBCs, with smaller cans and sample bottles for trials:

• Keep drums and IBCs tightly sealed in a cool, dry, ventilated place, away from direct sunlight and ignition sources.
• Prevent water and foreign matter from entering opened containers, and use clean pumps and lines to avoid cross-contamination.
• COA, TDS and SDS accompany every shipment; food contact and cosmetic grades carry the matching documentation and export marking.

Frequently Asked Questions

Q: How do I choose the viscosity grade?

A: Tell us the use and temperature, and we confirm the cSt: low viscosity spreads for defoaming, high viscosity for damping.

Q: Is PDMS soluble in water?

A: No, it is water insoluble and hydrophobic, ideal for foam control in water-based systems; miscible with nonpolar solvents.

Q: Do you supply food or cosmetic grade?

A: Yes. We offer cosmetic dimethicone and food contact grade used as the E900 antifoam, alongside the standard industrial fluid.