Bis(trimethylsiloxy)methylsilane

Product Details

CasNo： 1873-88-7

MF： C7H22O2Si3

Appearance： liquid

Delivery Time： 15 days

Packing： 200kg/drum

Purity： 99%

1. Basic Information

2. Physical Properties

Heptamethyltrisiloxane exhibits physical characteristics tailored for easy handling and formulation compatibility:

• Appearance: Colorless, transparent liquid (no turbidity, sediment, or discoloration).
• Boiling Point: 142°C (at 760 mmHg) – moderate boiling point, avoiding premature volatilization during processing while enabling easy separation in purification steps.
• Flash Point (Closed Cup): 22°C – classified as a highly flammable liquid; requires strict fire prevention measures (e.g., no open flames, electrostatic discharge control).
• Specific Gravity (25/25°C): 0.819 – less dense than water, facilitating mixing with organic solvents and reducing transportation weight.
• Refractive Index (n₂₀/D): 1.382 – a consistent optical property used for rapid purity verification in quality control.
• Viscosity (25°C): ~1.5 cSt – extremely low viscosity, ensuring smooth flow and uniform blending in liquid formulations (e.g., pesticide concentrates).
• Vapor Pressure (20°C): ~4.0 kPa – mild volatility, minimizing losses during storage but allowing quick dispersion in target applications (e.g., coating drying).
• Solubility: Insoluble in water (solubility <0.001 g/100 mL at 25°C); fully miscible with organic solvents (ethanol, acetone, xylene) and silicone fluids (e.g., polydimethylsiloxane), expanding its formulation flexibility.

3. Chemical Properties

The unique reactivity of its Si-H bond defines its core chemical value, while its siloxane backbone ensures stability:

• Reactive Si-H Bond: The central Si-H bond is highly active, enabling hydrosilylation reactions (catalyzed by platinum or rhodium complexes) with compounds containing unsaturated bonds (e.g., alkenes, alkynes). This reaction allows the introduction of functional groups (polyether, epoxy, amide) to synthesize modified silicones (e.g., polyether-modified trisiloxanes).
• Stable Siloxane Backbone: The linear −Si−O−Si− framework is chemically inert under normal conditions (room temperature, neutral pH). It resists hydrolysis, oxidation, and reactions with weak acids/alkalis, ensuring the compound’s stability during storage and pre-processing.
• Thermal Stability: Stable at temperatures below 180°C; decomposes only at temperatures >250°C (producing low-toxicity siloxane oligomers and hydrocarbons), making it suitable for high-temperature processing steps (e.g., coating curing at 150°C).
• Incompatibility: Reacts violently with strong oxidizers (e.g., potassium permanganate, hydrogen peroxide) and strong bases (e.g., concentrated sodium hydroxide), which may trigger decomposition or combustion. Avoid mixing with these substances.

4. Quality Standards

To meet the strict requirements of downstream modified silicone synthesis, the product adheres to rigorous industrial quality benchmarks:

• Purity (GC, Gas Chromatography): ≥99% – high purity eliminates impurities (e.g., low-molecular siloxanes, chlorosilanes) that could interfere with hydrosilylation reactions (e.g., catalyst poisoning, by-product formation).
• Si-H Content: ≥0.042 mol/g – ensures sufficient reactive sites for functional group modification, directly affecting the performance of end products (e.g., surface activity of polyether-modified trisiloxanes).
• Moisture Content: ≤0.03% – prevents hydrolysis of the Si-H bond (which would generate hydrogen gas and reduce reactivity) and avoids defects in end products (e.g., bubbles in coatings).
• Acidity (as HCl): ≤0.001% – prevents corrosion of equipment (e.g., stainless steel reactors) and degradation of sensitive functional groups in downstream synthesis (e.g., polyether chain cleavage).
• Metallic Impurities: ≤1 ppm (platinum, iron, copper) – avoids catalyst contamination in hydrosilylation reactions, ensuring consistent reaction rates and product quality.

5. Key Applications

As a foundational intermediate, its primary value lies in synthesizing high-performance modified silicones, with end-use spanning multiple industries:

5.1 Synthesis of Polyether-Modified Trisiloxanes (Core Application)

Through hydrosilylation with polyether monomers (e.g., allyl polyoxyethylene ether), it produces polyether-modified trisiloxanes – a class of high-efficiency surfactants with unique properties:

• Agricultural Adjuvants: These surfactants reduce the surface tension of pesticide sprays from ~72 mN/m (water) to ~25–30 mN/m, enabling better wetting and spreading on hydrophobic plant surfaces (e.g., waxy leaves of soybeans, cotton). This improves pesticide adhesion by 30–50% and enhances penetration into plant tissues, reducing pesticide usage by 15–20% while maintaining efficacy.
• Coating Additives: Added to water-based or solvent-based coatings, they improve flowability (reducing "orange peel" defects) and substrate wetting (ensuring uniform coverage on difficult-to-coat surfaces like metal or plastic). They also enhance coating leveling and reduce drying time by 10–15%.

5.2 Specialty Chemical Intermediates

• Functional Silicone Synthesis: Used to introduce silicone segments into organic polymers (e.g., epoxy resins, polyurethanes) via hydrosilylation, improving the polymers’ heat resistance (elevating continuous use temperature by 20–40°C) and water repellency.
• Surfactant Raw Material: Modified with epoxy or amide groups to produce specialty surfactants for personal care (e.g., hair conditioner softeners) and industrial cleaning (e.g., low-foam detergents for electronics).

5.3 Other Industrial Uses

• Lubricant Additive: Small amounts (0.5–2%) added to metalworking lubricants reduce friction between tools and workpieces, extending tool life by 15–25%.
• Solvent for Silicone Reactions: Serves as a low-toxicity, high-compatibility solvent in hydrosilylation reactions, ensuring uniform mixing of reactants and catalysts.

6. Packaging, Storage, and Transportation

6.1 Packaging

• Industrial Grade: Packaged in 200L plastic-lined iron drums or HDPE plastic drums (net weight: 150 kg/drum). The lining and drum material are chemically resistant to prevent corrosion and ensure airtightness.
• Small Batches/Laboratory Grade: Available in 20L HDPE buckets (net weight: 16 kg) or 1L amber glass bottles (for light-sensitive storage needs, though the compound is not highly photosensitive).
• Sealing Requirement: All packages use leak-proof lids with Teflon gaskets to prevent volatilization and moisture ingress.

6.2 Storage

• Environmental Conditions: Store in a cool, well-ventilated, fire-proof warehouse with a temperature range of 5–30°C. Avoid direct sunlight, high temperatures (e.g., near heaters), and humid environments (relative humidity <60%).
• Safety Measures:
  • Keep away from open flames, sparks, and ignition sources (e.g., electrical equipment without explosion-proof certification).
  • Isolate from incompatible substances: strong oxidizers, strong bases, and food/pharmaceutical products.
  • Equip the storage area with fire-fighting equipment (dry chemical powder extinguishers, CO₂ extinguishers) and leak absorption materials (vermiculite, inert absorbent pads).
• Shelf Life: 12 months from the production date under compliant packaging and storage conditions. Expired products must be re-tested for purity and Si-H content; if results meet standards, they can still be used.

6.3 Transportation

• Classified as a hazardous material (UN 1993) due to its flash point of 22°C. Comply with international/domestic regulations:
  • Maritime: Follow IMDG Code (stow in ventilated holds, away from heat sources).
  • Road/Rail: Use explosion-proof vehicles; avoid rough handling to prevent drum damage.
• Prohibit transportation with strong oxidizers, strong bases, or edible goods to avoid cross-contamination or accidents.

7. Safety and Regulatory Notes

• Toxicity: Low acute toxicity (oral LD₅₀ in rats:>3,000 mg/kg). However, inhalation of high-concentration vapors may cause mild respiratory irritation; direct skin contact can lead to temporary 脱脂 (degreasing) but no long-term damage. Wear chemical goggles, nitrile gloves, and a vapor respirator during operation.
• Fire Hazard: Highly flammable; its vapor can form explosive mixtures with air (explosion limit: 1.1–8.5% by volume). In case of fire, use dry chemical powder or CO₂ extinguishers (do not use water, as the product floats on water and may spread the fire).
• Regulatory Compliance: Meets EU REACH registration requirements and China’s GB/T industrial standards for organosilicon intermediates. For agricultural end-uses, ensure compliance with local pesticide adjuvant regulations (e.g., EPA standards in the US, EC 1107/2009 in the EU).