Heptamethyltrisiloxane

Basic Product Information

• Product Name: Heptamethyltrisiloxane
• Appearance: Colorless Transparent Liquid

TYPICAL PROPERTIES

Appearance	colorless transparent liquid
purity  (GC),%	>99
Molecular weight	222.5

Physical Properties

• Appearance and State: Typically a colorless, transparent liquid with low viscosity and high volatility.
• Odor: May have a slight ether-like or organic solvent odor, depending on purity.
• Boiling and Melting Points: Low boiling point (usually in the range of 150–200°C) and low melting point (possibly below 0°C).
• Density: Lower than water (approximately 0.8–0.9 g/cm³), characteristic of organosilicon compounds.
• Solubility: Soluble in most organic solvents (e.g., toluene, acetone, ethanol) but insoluble in water.
• Volatility: Highly volatile; requires airtight storage.

Chemical Properties

• Stability: Relatively stable under heat and chemical reagents but may decompose under strong acids, strong bases, or high temperatures.
• Reactivity:
• Hydrolysis: Siloxane bonds (Si-O-Si) may hydrolyze under acidic or alkaline conditions, forming silanols (Si-OH).
• Reaction with Active Metals: May react with metals such as lithium or magnesium to form metal-silicon compounds.
• Oxidation: May oxidize under high temperatures or strong oxidizing agents, producing silica (SiO₂) and other byproducts.
• Functional Group Characteristics: Contains methyl groups (-CH₃) and siloxane bonds (Si-O-Si), with the latter providing flexibility and thermal stability.
• Flammability: Flammable; combustion may release carbon dioxide, carbon monoxide, and silica.
• Reactions with Other Reagents: May react with Grignard reagents or organolithium compounds, undergoing silicon-carbon bond substitution.

Product Functions

• Hydrophobic Modification: Imparts water-repellent properties, reduces surface energy, and enhances material waterproofing.
• Surface Activity Adjustment: Acts as a surfactant or additive to regulate liquid surface tension, improving wettability or spreading ability.
• Chemical Intermediate: Serves as a key intermediate in organosilicon synthesis for constructing complex siloxane structures.
• Thermal Stability Enhancement: Siloxane bonds (Si-O-Si) provide excellent thermal stability, suitable for material modification in high-temperature environments.
• Rheological Property Adjustment: Modifies viscosity and flow behavior of liquid or colloidal systems, enhancing processability.
• Adhesion Promotion: Functions as a coupling agent or additive to improve bonding performance between dissimilar materials.
• Oxidation Resistance: Under specific conditions, slows oxidative degradation of materials, extending service life.
• Volatile Carrier Function: Acts as a volatile solvent or carrier to ensure uniform dispersion or rapid evaporation of other components.
• Chemical Reaction Control: Participates in reactions such as hydrosilylation and hydrolysis-condensation, influencing the structure and properties of final products.
• Inert Protection: Provides inert shielding during chemical reactions or storage to minimize side reactions.

Application

• Organosilicon Materials Industry
• Silicone Oil Synthesis: Used as short-chain siloxane monomers to prepare methyl silicone oil, phenyl silicone oil, and similar products.
• Silicone Resin Modification: Functions as a crosslinking agent or end-capping agent to adjust the flexibility and temperature resistance of silicone resins.
• Silicone Rubber Additives: Improves processing fluidity or surface properties of silicone rubber.
• Surface Treatment & Functional Coatings
• Waterproof Coatings: Applied for hydrophobic treatment on glass, ceramic, or metal surfaces (e.g., construction waterproofing, automotive rain-repellent glass coatings).
• Anti-Fouling Coatings: Used in marine anti-fouling paints or kitchenware anti-grease coatings.
• Optical Coatings: Reduces reflection and fingerprint adhesion on lenses or display screens.
• Personal Care & Cosmetics
• Skincare Products: Serves as volatile silicone oil in sunscreens or foundations to deliver a lightweight, non-greasy texture.
• Haircare Products: Enhances hair softness and shine in shampoos or conditioners.
• Makeup Fixation: Helps mascara, eyeliners, etc., achieve long-lasting hold and easy removal.
• Electronics & Semiconductor Industry
• Electronic Encapsulation: Acts as a modifier for encapsulation materials to improve high-temperature resistance and insulation.
• Semiconductor Coatings: Used for temporary protective layers on wafers or as components in photoresists.
• Thermal Interface Materials: Enhances wettability and thermal stability of thermal greases/pads.
• Industrial Manufacturing & Processing
• Release Agents: Applied in tire or plastic molding to reduce adhesion during demolding.
• Lubricant Additives: Lowers friction coefficients in high-temperature lubricants (e.g., bearings, gears).
• Foam Control: Suppresses foam formation in petroleum extraction or wastewater treatment.
• Pharmaceuticals & Biomaterials
• Drug Carriers: Utilized as components in hydrophobic drug delivery systems (e.g., anticancer agents).
• Medical Silicones: Improves biocompatibility and flexibility of catheters or implants.
• Medical Device Coatings: Provides anti-adhesive or antimicrobial coatings for surgical instruments.
• Specialty Chemicals & Research
• Coupling Agent Precursors: Synthesizes silane coupling agents (e.g., for glass-fiber-reinforced plastics).
• Nanomaterial Modification: Modifies silica nanoparticles to enhance dispersibility.
• Reaction Intermediates: Builds complex siloxane structures in organic synthesis.
• New Energy & Environmental Technologies
• Lithium Battery Materials: Serves as electrolyte additives to enhance high-temperature stability.
• Photovoltaic Components: Applied in anti-dust or hydrophobic coatings for solar panels.
• Eco-Friendly Coatings: Develops low-VOC (volatile organic compounds) green coating systems.

Core Advantages

Properties	Core Advantages	Typical Data/Performance	Application Relevance	Properties
Chemical Stability	Resistant to acids, alkalis, and oxidation; stable across a broad pH range	Stable under pH 3–11 conditions	Pharmaceutical carriers, electronic encapsulation, industrial coatings	Chemical Stability
Thermal Stability	Resists decomposition at high temperatures; suitable for high-temperature processes	Thermal decomposition temperature >250°C	High-temperature lubrication, semiconductor encapsulation, heat-resistant coatings	Thermal Stability
Low Surface Energy	Provides excellent hydrophobicity and anti-adhesion	Water contact angle >100°	Waterproof coatings, anti-fouling surfaces, release agents	Low Surface Energy
Volatility	Rapid volatilization without residue; adjusts system viscosity	Boiling range: 150–200°C (varies by isomer)	Cosmetics, temporary protective coatings, leveling agents	Volatility
Compatibility	Highly compatible with organic solvents, resins, and silicone materials	Soluble in toluene, acetone, ethanol, etc.	Compound modification, formulation additives	Compatibility
Rheological Adjustment	Reduces system viscosity and improves flowability	Viscosity <10 mPa·s (25°C)	Coatings, inks, injection molding	Rheological Adjustment
Safety & Eco-Friendliness	Low toxicity; complies with cosmetic and pharmaceutical standards	FDA 21 CFR 175.300 certification (indirect food contact)	Personal care, medical devices	Safety & Eco-Friendliness
Reactivity	Hydrolyzable/condensable siloxane bonds; easily functionalized	Reacts with amino, epoxy groups, etc.	Coupling agent synthesis, nanomaterial modification	Reactivity

Experimental Data & Case Studies

Pesticide Industry

• Experimental Data: Reduces water surface tension to below 21 mN/m, cutting pesticide consumption by 30–50%.
• Case Study: In trials against citrus red mites and strawberry aphids, heptamethyltrisiloxane modified with polyether (at a 100:1 dilution ratio) demonstrated efficacy comparable to Silwet 408 organosilicon at the same concentration.

Coatings Industry

• Experimental Data: Lowers coating surface tension from 30–40 mN/m to 20–25 mN/m.
• Case Study: Applied in metal coatings to minimize sagging and orange peel effects; used in architectural coatings to enhance adhesion and water resistance.

Electronics Industry

• Experimental Data: Reduces semiconductor chip surface contact angles from 70°–80° to 30°–40°.
• Case Study: A semiconductor manufacturer adopted it as a release agent for printed circuit boards, achieving smooth demolding and high surface quality.

Textile Industry

• Experimental Data: Post-treatment reduces static friction coefficients to 0.2–0.3 and kinetic friction coefficients to 0.1–0.2.
• Case Study: A textile mill used it in premium shirt fabrics, producing soft, water-repellent materials with reduced static buildup.

Cosmetics Industry

• Experimental Data: Lowers emulsion viscosity by 10–20% and improves skin luminosity by 15–25% when added to lotions.
• Case Study: A cosmetics brand incorporated it into conditioners, earning consumer praise for silky, glossy hair results.

Usage Guidelines & Precautions

Usage Guidelines

• Pesticide Industry

Application: Add as an adjuvant, comprising 0.1–0.5% of total pesticide mass.

Procedure:

Weigh pesticide first.

Add adjuvant.

Mix with water and stir thoroughly.

Example: Add 1–5 mL of adjuvant per 1000 mL pesticide solution.

• Coatings Industry

Application: Incorporate during grinding or paint formulation, at 0.2–2% of total coating mass (adjust based on system requirements).

Example: Add 0.2–2 kg adjuvant per 100 kg latex paint to improve leveling and gloss.

• Electronics Industry

Application: Use as a surface treatment agent via spraying, dipping, or brushing.

Example: For PCB demolding, prepare a 1–5% solution, dip the board for seconds, then air-dry.

• Textile Industry

Methods:

Pad-Dry Method: Immerse fabric in a finishing bath containing 0.5–3% adjuvant, pad, then dry.

Coating Method: Apply finishing agent to fabric surface and dry.

Example: Use 1–2% concentration for cotton fabric treatment.

• Cosmetics Industry

Application: Add during emulsion preparation at 0.5–3% of total formulation.

Example: Incorporate 0.5–3 kg adjuvant per 100 kg lotion/cream during emulsification.

Precautions

• Storage:

Store in a cool, ventilated area (<30°C), away from ignition sources and heat.

Keep containers sealed to prevent moisture absorption and thermal degradation.

• Safety:

Flammable – Keep away from open flames, heat, and strong oxidizing agents.

Ensure adequate ventilation in work areas to avoid vapor accumulation.

Wear PPE (gloves, goggles); rinse immediately with water if contacted and seek medical help.

• Compatibility:

Test compatibility before mixing with other chemicals.

Avoid reactions with strong acids/bases in pesticides or coatings.

• Dosage Control:

Strictly follow recommended dosages.

Overuse may cause phytotoxicity (pesticides) or compromise stability/safety (cosmetics).

Packaging & Ordering

Packaging: 200kg/1000kg plastic drums (customizable).