Product Details

CasNo： 63148-62-9

MF： C6H18OSi2

Appearance： liquid

Delivery Time： 15 days

Packing： 200kg/drum

Purity： 99%

Product Details of Dimethyl Silicone Oil (Polydimethylsiloxane, PDMS)

Dimethyl Silicone Oil, scientifically known as Polydimethylsiloxane (PDMS), is a versatile hydrophobic organosilicon polymer. Its unique combination of thermal stability, chemical inertness, low surface tension, and adjustable viscosity makes it indispensable across industries ranging from electronics to healthcare. Below is its comprehensive product information:

1. Basic Information

2. Physical Properties

PDMS exhibits adjustable physical properties primarily determined by its viscosity (controlled by n). Below are core properties and variations across viscosity grades:

2.1 Core Physical Properties (Typical Ranges)

2.2 Solubility

• Insoluble in: Water, methanol, acetone, and ethanol (hydrophobic and low polarity).
• Miscible with: Chlorinated hydrocarbons (chloroform, dichloromethane), benzene, toluene, xylene, n-hexane, mineral spirits, ether, and amyl acetate.
• Sparingly soluble in: Isopropyl alcohol (solubility <0.1 g/100 mL at 25°C).

3. Chemical Properties

PDMS’s chemical behavior is defined by its stable Si-O-Si backbone and inert methyl groups:

• Exceptional Thermal Stability:

  • Trimethylsilyl-terminated PDMS (most common grade): Starts decomposing at 390–400°C (producing low-molecular-weight cyclic siloxanes).
  • Silanol-terminated PDMS: Decomposition onset at 350–370°C (slightly lower due to reactive -OH groups).
  • Impurities (e.g., KOH catalyst residues) reduce stability—purified grades maintain performance at 200–250°C for long-term use.

• Polymerization-Depolymerization Equilibrium:
  PDMS exists in a dynamic equilibrium between polymer chains and cyclic oligomers (e.g., octamethylcyclotetrasiloxane, D4). High temperature (>250°C) and reduced pressure shift the equilibrium toward depolymerization, releasing volatile cyclics—this property is used for recycling or purification.

• Controlled Reactivity:

  • Introducing vinyl groups (−CH=CH2​) into the backbone (via copolymerization with methylvinylsiloxane) produces vinyl-modified PDMS, which crosslinks with Si-H silicones (hydrosilylation) to form silicone rubber.
  • Under peroxide catalysis (e.g., benzoyl peroxide), PDMS undergoes free-radical crosslinking, enabling curing into elastomers or resins.
  • Inert under normal conditions: No reaction with weak acids, weak bases, or most organic/inorganic compounds (avoids degradation in harsh environments).

• Oxidation Resistance: Resists oxidation by air or mild oxidizers at temperatures <250°C; strong oxidizers (e.g., concentrated H₂O₂) may cleave the Si-O bond at elevated temperatures.

4. Key Quality Standards

To meet industry-specific requirements, PDMS adheres to graded quality benchmarks, with electrical and purity parameters as critical indicators:

Complies with global standards: ASTM D1006 (viscosity), ISO 2909 (electrical properties), and USP 39-NF 34 (medical grade).

5. Key Applications

PDMS’s versatility enables its use in over 50 industries, with core applications spanning:

5.1 Electrical & Electronics

• Insulating Medium: Used in motors, transformers, capacitors, and electronic instruments as a heat-resistant, arc-resistant, and moisture-proof insulator. It maintains insulation performance at -60°C to 200°C, extending equipment lifespan by 30–50%.
• Thermal Management: High-viscosity PDMS (5,000–100,000 cSt) acts as a thermal grease for CPU/GPU cooling, improving heat transfer efficiency by 20–30% compared to mineral oil-based greases.

5.2 Mold Release & Processing

• Mold Release Agent: Dominates the mold release market for plastics (e.g., ABS, PC), rubber, metal casting, and glass products. Key advantages:
  • High release efficiency (≥99% success rate for complex shapes).
  • No residue on finished parts (avoids post-processing cleaning).
  • Reduces mold wear (extends mold life by 2–3 times).
• Plastic/Rubber Additive: Added (0.1–1.0% dosage) to polymers to improve flowability (reducing "orange peel" defects) and surface smoothness.

5.3 消泡 & Lubrication

• Industrial Defoamer: The most widely used 消泡剂 globally, with applications in oil refining, chemical processing, printing, and pharmaceuticals. It eliminates foam at temperatures -50°C to 250°C, with an efficiency 5–10 times higher than organic 消泡剂.
• High-Performance Lubricant: Used for rubber/plastic bearings, precision instruments, and automotive components. Key benefits:
  • Wide temperature range (-60°C to 250°C) – outperforms mineral oils (limited to -20°C to 120°C).
  • Non-corrosive to metals and compatible with elastomers (no swelling or cracking).

5.4 Surface Treatment & Coatings

• Waterproof Agent: Applied to glass, ceramics, leather, and textiles via spraying or dipping. It forms a hydrophobic layer (water contact angle >110°) that improves water resistance without affecting breathability (critical for outdoor fabrics).
• Coating Additive: Added to paints and coatings (0.5–2.0% dosage) to enhance scratch resistance, gloss, and weatherability (extends coating service life by 5–8 years).

5.5 Healthcare & Personal Care

• Medical Applications:
  • Pharmaceuticals: Used as an anti-foaming agent in artificial lung machines and to treat pulmonary edema (reduces alveolar foam).
  • Medical Devices: Coats catheters and surgical instruments to reduce tissue adhesion and improve biocompatibility.
  • Topical Products: Serves as a base in ointments and skin protectants (non-irritating, non-comedogenic).
• Cosmetics: A common ingredient in skincare (moisturizers), haircare (conditioners), and makeup (foundations). It provides a silky texture, improves spreadability, and locks in moisture.

6. Packaging, Storage, and Shelf Life

6.1 Packaging

• Industrial Grade (Low Viscosity, <1,000 cSt): 200L HDPE drums (net weight: 160–180 kg) or 20L plastic buckets (16–18 kg).
• Industrial Grade (High Viscosity, >1,000 cSt): 200L lined steel drums (prevents viscosity changes from metal contact) or 1,000L ISO tanks (bulk supply).
• Medical/Food Grade: 20L stainless steel buckets or 200L stainless steel drums (sterile grades: double-sealed with ethylene oxide sterilization).
• Small Batches/Laboratory Grade: 1L/5L amber glass bottles (prevents light-induced degradation, though PDMS is not highly photosensitive).

6.2 Storage

• Environmental Conditions: Store in a cool, dry, well-ventilated area at ≤25°C. Avoid direct sunlight, high temperatures (e.g., near heaters), and humid environments (relative humidity <60%).
• Safety Precautions:
  • Low-viscosity grades (<100 cSt) with flash points <60°C: Classified as flammable liquids (UN 1993). Keep away from open flames and electrostatic sources; install explosion-proof ventilation.
  • High-viscosity grades (>10,000 cSt): Non-flammable, but avoid mixing with strong oxidizers (e.g., H₂O₂).
• Handling Notes: Use clean, dry equipment to transfer PDMS—contamination with water or oils may affect performance (e.g., reduced insulation).

6.3 Shelf Life

• Under compliant packaging and storage conditions:
  • Industrial grade: 24 months from the production date.
  • Medical/food grade: 18 months (due to stricter purity requirements).
• Expired products must be re-tested for viscosity, volatile content, and electrical properties (if applicable). If results meet standards, they can continue to be used.

7. Regulatory Compliance

• Global Standards:
  • EU: REACH-registered (No. 01-2119456243-55-XXXX) and compliant with EC 1935/2004 (food-contact materials).
  • US: FDA 21 CFR §177.2600 (food-contact) and USP Class VI (medical use).
  • China: GB/T 20214 (dimethyl silicone oil) and GB 4806 (food-contact safety).
• Industry-Specific Compliance:
  • Electronics: Meets IEC 60156 (insulating liquids) and SEMI C36 (semiconductor process materials).
  • Automotive: Complies with ASTM D471 (rubber compatibility) for under-the-hood applications.