Divinyltetramethyldisiloxane

Product Details

CasNo： 2627-95-4

MF： C8H18OSi2

Appearance： liquid

Delivery Time： 15 days

Packing： 200kg/drum

Purity： 99%

1. Basic Information

2. Physical Properties

DVTMDSO exhibits physical characteristics optimized for compatibility with silicone formulations and ease of processing:

• Appearance: Colorless, transparent liquid (no turbidity, sediment, or yellowing; visual clarity indicates low impurity levels).
• Density (25°C): 0.809 g/mL – less dense than water, facilitating uniform mixing with silicone polymers (e.g., vinyl-terminated polydimethylsiloxane).
• Melting Point: -99°C – remains liquid even in extreme cold (e.g., winter storage or low-temperature processing), eliminating the need for heating to restore fluidity.
• Boiling Point: 139°C (at 760 mmHg) – moderate boiling point, avoiding premature volatilization during compounding (e.g., silicone rubber mixing) while enabling easy removal of excess via vacuum stripping.
• Flash Point (Closed Cup): 24°C – classified as a highly flammable liquid; strict fire prevention and electrostatic discharge control are required.
• Refractive Index (n₂₀/D): 1.411–1.412 – a precise optical parameter used for rapid purity verification in quality control (deviations indicate impurity contamination).
• Specific Gravity (25/25°C): 0.818 – consistent with typical silicone intermediates, ensuring predictable dosing in formulations.
• Vapor Pressure (25°C): 17 hPa – mild volatility, minimizing losses during storage but allowing efficient removal of unreacted material post-curing.
• Solubility: Sparingly soluble in water (solubility <0.01 g/100 mL at 25°C); fully miscible with organic solvents (ethyl acetate, dichloromethane, toluene) and silicone fluids (e.g., vinyl 硅油，methylphenyl silicone oil), supporting flexible formulation design.

3. Chemical Properties

Its reactivity stems from vinyl groups, while the siloxane backbone ensures stability—balancing performance and processability:

• High Reactivity of Vinyl Groups: The terminal −CH=CH2​ groups readily undergo hydrosilylation reactions (catalyzed by platinum complexes) with Si-H-containing compounds (e.g., hydrogen-terminated silicones). This reaction enables crosslinking of silicone polymers, forming three-dimensional networks that define the mechanical properties (elasticity, tensile strength) of addition-cure silicones.
• Moderate Hygroscopicity: Absorbs trace moisture from air over time (hygroscopicity: ~0.1%/month at 50% relative humidity). Moisture does not degrade DVTMDSO but may affect the activity of platinum catalysts in downstream reactions—hence sealed storage is recommended.
• Thermal Stability: Stable at temperatures below 150°C; decomposes only at temperatures >280°C (producing low-toxicity siloxane oligomers and hydrocarbons). This stability ensures no premature reaction during high-temperature compounding (e.g., silicone rubber mixing at 120°C).
• Inertness of Siloxane Backbone: The central Si-O-Si bond is chemically inert under normal conditions, resisting hydrolysis, oxidation, and reactions with weak acids/alkalis. This protects the molecule from degradation during storage and pre-processing.
• Incompatibility: Reacts violently with strong oxidizers (e.g., potassium permanganate, chlorine) and free-radical initiators (e.g., benzoyl peroxide), which may trigger uncontrolled polymerization of vinyl groups. Avoid mixing with these substances.

4. Quality Standards

To meet the strict requirements of addition-cure silicone production, the product adheres to rigorous industrial benchmarks:

5. Key Applications

DVTMDSO is the "core crosslinker" for addition-cure silicones, with end-uses spanning high-value industries:

5.1 Addition-Cure Silicone Rubber & Molding Compounds

• Crosslinking Agent: Added to vinyl-terminated silicone rubber (1–3% dosage) to react with Si-H crosslinkers via hydrosilylation. This crosslinking forms elastic networks, giving the rubber excellent properties:
  • Tensile strength: 3–8 MPa (depending on formulation).
  • Elongation at break: 200–800%.
  • High-temperature resistance: Continuous use at 200–250°C.
• Mold-Making Silicones: Used in addition-cure mold 胶 (molding compounds) for casting resins, plastics, and candles. It ensures the mold has high tear resistance (>20 kN/m) and low shrinkage (<0.1%), enabling precise replication of complex shapes.

5.2 Specialty Silicone Materials

• Silicone Gels & Liquid Silicone Rubbers (LSR): In medical-grade silicone gels (e.g., breast implants, wound dressings), it acts as a crosslinker to control gel hardness (Shore 00: 10–40). For LSR (used in baby bottle nipples, automotive seals), it ensures fast curing (10–30 seconds at 180°C) and consistent mechanical performance.
• Vinyl Silicone Resins & Oils: As a monomer in vinyl silicone resin synthesis, it improves the resin’s heat resistance (decomposition temperature>400°C) and adhesion to metal substrates. In vinyl 硅油 production, it serves as a chain extender to adjust molecular weight and viscosity.

5.3 Catalyst & Additive Synthesis

• Platinum Complex Stabilizer: Reacted with platinum compounds to form stable platinum-vinyl complexes, which are used as catalysts for hydrosilylation. These complexes prevent catalyst deactivation during storage and ensure uniform curing of silicones.
• Surface Modifier: Derivatized with functional groups (e.g., epoxy, amino) to produce silicone surfactants for coatings—improving substrate wetting and reducing surface tension.

6. Safety Information

7. Packaging, Storage, and Shelf Life

7.1 Packaging

• Industrial Grade: Packaged in 200L galvanized iron drums or HDPE plastic drums (net weight: 160 kg/drum) that meet UN 1993 hazardous material packaging standards. Drums are sealed with Teflon gaskets to prevent moisture ingress and volatilization.
• Small Batches/Laboratory Grade: Available in 20L HDPE buckets (net weight: 16 kg) or 1L amber glass bottles (for light-sensitive storage, though DVTMDSO is not highly photosensitive) with leak-proof caps.

7.2 Storage

• Environmental Requirements: Store in a cool, dry, well-ventilated, fire-proof warehouse at ≤25°C. Avoid direct sunlight, high temperatures (e.g., near heaters), and humid environments (relative humidity <50%).
• Safety Measures:
  • Keep away from open flames, sparks, and ignition sources (e.g., uncertified electrical equipment). Install explosion-proof ventilation and electrostatic grounding devices.
  • Store separately from strong oxidizers, free-radical initiators, and food/pharmaceutical products to avoid cross-contamination or reactions.
  • Use only non-sparking tools (e.g., brass scoops) when handling to prevent electrostatic discharge.

7.3 Shelf Life

Under compliant packaging and storage conditions, the shelf life is 12 months from the production date. Expired products must be re-tested for purity, vinyl content, and moisture—if results meet quality standards, they can continue to be used.

8. Regulatory Compliance

• Global Standards: Complies with EU REACH Registration (No. 01-2119456243-48-XXXX) and UN GHS Hazard Communication Standards.
• Industry-Specific Compliance: For medical-grade silicone applications, meets USP Class VI (US Pharmacopeia) and ISO 10993 (biocompatibility) requirements when used as a raw material.
• Transport Regulations: Adheres to IMDG Code (maritime), ADR (road, Europe), and 49 CFR (road, US) for hazardous material transportation.