Applications of Low- and High-Viscosity Dimethyl Silicone Oil (Polydimethylsiloxane/PDMS)
General classification: Low-viscosity oils (typically 5–100 cSt) feature good fluidity, rapid spreading, and relatively high volatility; high-viscosity oils (≥1000 cSt) are viscous, form durable films, have extremely low volatility, and provide strong damping effects. Shared properties include resistance to high and low temperatures (-50 to 200°C), hydrophobicity, chemical inertness, electrical insulation, and low surface tension.
I. Low-Viscosity Dimethyl Silicone Oil (5–100 cSt)
Key characteristics: Good fluidity, strong penetrability, rapid spreading, and a light, non-greasy skin feel.
1. Personal Care
Lotions, creams, sunscreens, color cosmetics, and hair sprays. Spreads quickly to form a thin, hydrophobic, and breathable film without feeling heavy or greasy; improves wet-combing properties and smooths hair cuticles in hair care products; volatile low-viscosity silicone oil often serves as a carrier for antiperspirants.
2. Defoaming (One of the most classic applications)
Chemical industry, coatings and inks, wastewater treatment, and food fermentation (food-grade). Low surface tension allows for rapid diffusion to the foam interface and quick bubble rupture; suitable for low-viscosity foaming systems.
3. Electronics and Electrical
Moisture-proof insulating coatings for circuit boards and sensors (penetrates tiny gaps);
Heat transfer media and insulating impregnating fluids for small devices;
Lubrication for precision connectors and miniature bearings.
4. Textiles and Leather
Softeners and water-repellent finishing agents for synthetic fabrics; smooth-feel agents for leather (penetrates fibers to improve softness and reduce static electricity).
5. Mold Release, Lubrication, and Additives
Simple mold release agents for plastics/rubber; internal lubricants for plastics; leveling agents for coatings and polishes (enhances gloss, prevents craters/fisheyes); heat transfer fluids for laboratory oil baths and rotary evaporators.
6. Pharmaceutical Excipients (Pharmaceutical-grade)
Oral defoaming (for flatulence) and endoscopic defoaming; base for topical creams (forms a light, hydrophobic protective film). II. High-Viscosity Dimethyl Silicone Oil (≥1,000 cSt; >10,000 cSt classified as ultra-high viscosity)
Key characteristics: High viscosity, strong oil film adhesion, resistance to migration, minimal volatility, and outstanding damping/cushioning performance.
1. Damping and Shock Absorption (Signature Application)
Damping oil for instruments (pressure gauges, flow meters, optical instrument focusing mechanisms); cushioning hinges for furniture, toilet seat dampers, and automotive shock-absorbing components; liquid springs and shock absorbers—providing smooth cushioning via viscous resistance with stable damping performance across a wide temperature range.
2. Long-lasting High-Temperature Lubrication
Micro-gears in watches, cameras, and optical instruments; high-temperature drive components in ovens and kilns; long-lasting lubrication for rubber/plastic O-rings and seals (non-corrosive to rubber/plastic, resistant to carbonization at high temperatures); also serves as a base material for silicone greases and damping pastes.
3. Mold Release Agent (Heavy-duty Molds)
Release agent for large rubber, plastic, and die-casting molds; forms a dense, durable film resulting in high-gloss finished parts; suitable for continuous, long-term production.
4. Rubber/Plastic Modification & Coating Additives
Additive for plastic and rubber processing to enhance weather resistance, wear resistance, and mold release properties; enhances gloss, water resistance, and anti-blocking properties in paints, polishing waxes, and automotive polishes.
5. Electronic Insulation and Protection
Insulating medium for transformers and capacitors; moisture-proof, anti-mold, and dust-proof coatings for electronic components; forms a durable, hydrophobic insulating film on glass and ceramic surfaces after heat treatment.
6. Personal Care & Pharmaceuticals
Ingredient in hair conditioners and masks for lasting smoothness and shine; base for medicinal ointments (film-forming for sustained release); pharmaceutical mold release agent to prevent tablets and suppositories from sticking to molds.
