Decamethylcyclopentasiloxane

Product Details

CasNo： 541-02-6

MF： C10H30O5Si5

Appearance： liquid

Delivery Time： 15 days

Packing： 190kg/drum

Purity： 99%

Basic Information​

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2. Physical Properties​

D5 exhibits physical characteristics that make it highly adaptable to diverse application scenarios, especially in personal care:​

• Appearance: Colorless, transparent, low-viscosity liquid (no turbidity or sediment).​

• Density (25°C): ​

0.958g/cm3

• (slightly denser than water, easy to handle and mix).​

• Boiling Point: 210.0°C (at 760 mmHg, high enough to avoid premature volatilization at room temperature).​

• Melting Point: -44°C (remains liquid even in cold environments, no need for insulation during low-temperature storage).​

• Flash Point (Closed Cup): 73°C (classified as a moderately flammable liquid; requires basic fire prevention measures).​

• Refractive Index (n₂₀/D): 1.396 (lit., consistent with typical cyclic siloxane optical properties, used for purity verification).​

• Viscosity (25°C): ~3.8 cSt (low viscosity, enabling smooth spreading in cosmetics and uniform mixing in industrial formulations).​

• Volatility: Slowly volatile at room temperature (vapor pressure: ~0.13 kPa at 20°C)—evaporates completely without residue, a key advantage for personal care products (e.g., no sticky film on skin/hair).​

• Solubility: Insoluble in water (solubility <0.01 g/100 mL at 25°C); miscible with most organic solvents (ethanol, ether, mineral oil) and silicone oils (e.g., polydimethylsiloxane), expanding its formulation flexibility.​

3. Chemical Properties​

• High Stability: Under standard storage and usage conditions (sealed containers, room temperature, away from strong oxidizers), D5 maintains excellent chemical stability. It does not react with water, weak acids, or weak alkalis, ensuring long-term shelf life of products containing D5.​

• Inertness to Common Substances: Does not interact with active ingredients in cosmetics (e.g., vitamins, sunscreens) or industrial additives (e.g., lubricant additives), avoiding product degradation or performance loss.​

• Ring-Opening Polymerization Potential: Similar to other cyclic siloxanes, D5 can undergo ring-opening polymerization under the action of acid/alkali catalysts or high temperatures to form linear silicone polymers (e.g., silicone oils, silicone rubbers)—though this is less common than D4’s polymerization; its primary value lies in direct application rather than as a polymer intermediate.​

• Decomposition Behavior: In extreme conditions (e.g., open flame, high temperature >300°C), it may decompose to produce carbon oxides (CO, CO₂), hydrocarbons, and silicon-containing oxides. No toxic by-products are released under normal application temperatures.​

4. Production Method​

Industrial-scale production of D5 primarily uses dimethyl dichlorosilane (DMCS) as the raw material, following a mature three-step process:​

1. Hydrolysis of DMCS: Dimethyl dichlorosilane is mixed with deionized water in a reactor for hydrolysis, generating dimethylsilanediol ​

(CH3​)2​Si(OH)2​

2. and by-product hydrochloric acid (HCl). The HCl is separated and recycled for other industrial uses (e.g., metal pickling).​

1. Condensation & Cyclization: Dimethylsilanediol undergoes self-condensation under the catalysis of dilute sulfuric acid or cation exchange resins, forming a mixture of cyclic siloxanes (including D4, D5, D6, etc.) and linear oligomers.​

1. Purification by Distillation: The cyclic siloxane mixture is subjected to vacuum fractional distillation (operating pressure: -0.095 MPa, temperature: 150–180°C) to separate D5 from other components. High-purity D5 (purity ≥99%) is obtained by controlling the distillation reflux ratio and temperature, meeting industrial and cosmetic-grade requirements.​

5. Key Applications​

D5’s unique combination of volatility, inertness, and skin-friendliness drives its widespread use across multiple sectors:​

5.1 Personal Care & Cosmetics (Largest Application)​

• Hair Care Products: Added to shampoos, conditioners, and hair serums to:​

• Reduce wet combing resistance by over 40% (lubricates hair strands, minimizing breakage).​

• Impart a fluffy, non-greasy texture to dry hair (evaporates after application, avoiding hair clumping).​

• Skin Care & Makeup: Used in moisturizers, foundations, concealers, and antiperspirants:​

• In creams/lotions: Adjusts 肤感 (skin feel) to be smooth and lightweight, reducing greasiness.​

• In sunscreens/foundations: Improves the spreadability of active ingredients (e.g., zinc oxide) and enhances product adherence to skin.​

• In antiperspirants: Acts as a volatile carrier—evaporates quickly to prevent white residue from antiperspirant salts (e.g., aluminum chlorohydrate) on skin/clothing.​

• Oral Care: Occasionally used in mouthwashes as a solvent for oil-soluble antibacterial agents, ensuring uniform distribution and reducing oral irritation.​

5.2 Industrial Applications​

• Lubricants & Mold Release Agents: Used as a base oil or additive in metalworking lubricants (reduces friction during machining) and plastic/rubber mold release agents (ensures easy demolding without surface defects on products).​

• Coatings & Inks: Added to industrial coatings (e.g., high-temperature resistant coatings) and printing inks to improve flowability, reduce surface tension, and minimize defects like orange peel or pinholes.​

• Precision Cleaning: Serves as a low-toxicity solvent for cleaning precision instruments (e.g., optical lenses, electronic components)—evaporates completely, leaving no residue that could damage sensitive parts.​

5.3 Pharmaceutical Field​

• Acts as a carrier in drug delivery systems (e.g., transdermal patches, topical ointments). Its good skin permeability helps enhance the absorption of lipid-soluble drugs, while its inertness ensures no interaction with pharmaceutical active ingredients.​

6. Packaging, Storage, and Shelf Life​

6.1 Packaging​

• Industrial Grade: Available in 190 kg HDPE plastic drums (standard packaging for small-to-medium batches) and 950 kg IBC totes (intermediate bulk containers) (for large-volume industrial procurement). For bulk orders, ISO tank containers (20–25 tons) are provided to reduce logistics costs.​

• Cosmetic Grade: Packaged in 20 kg food-grade HDPE buckets (to avoid contamination) or 1 kg amber glass bottles (for laboratory-scale or small-batch cosmetic R&D). All packaging is sealed with leak-proof lids to prevent volatilization and moisture ingress.​

6.2 Storage​

• Environmental Requirements: Store in a cool, dry, well-ventilated warehouse with a temperature not exceeding 30°C. Avoid direct sunlight, open flames, and heat sources (e.g., heaters).​

• Compatibility: Keep away from strong oxidizers (e.g., potassium permanganate), concentrated acids (e.g., sulfuric acid), and strong alkalis (e.g., sodium hydroxide)—these substances may trigger decomposition or polymerization of D5.​

• Safety Measures: Equip the storage area with appropriate fire-fighting equipment (dry chemical powder extinguishers, CO₂ extinguishers) and leakage treatment tools (absorbent pads, neutralizing agents).​

6.3 Shelf Life​

Under compliant packaging and storage conditions, the shelf life of D5 is 24 months from the production date. Expired products can be re-inspected for key indicators (purity, moisture content, acidity); if results meet quality standards, they can continue to be used.​

7. Regulatory Compliance & Safety Notes​

• Regulatory Status: Complies with global regulations for cyclic siloxanes:​

• EU: Restricted in leave-on cosmetics (concentration ≤0.1% by weight) under Regulation (EC) No 1223/2009; permitted in rinse-off products and industrial applications.​

• US: Approved by the FDA for use in cosmetics and food-contact materials (21 CFR §177.2600).​

• China: Meets GB/T 30942-2014 Technical Requirements for Cyclic Siloxanes (D4, D5, D6) for industrial and cosmetic-grade products.​

• Safety:​

• Toxicity: Low acute toxicity (oral LD₅₀ in rats: >5,000 mg/kg; skin irritation: non-irritating in rabbit tests).​

• Environmental Impact: Moderately biodegradable (biodegradation rate ~30% in 28 days under aerobic conditions). Some regions (e.g., the EU) have imposed environmental risk assessments due to its potential persistence in aquatic environments—users should follow local discharge regulations.​

• Handling Precautions: Avoid prolonged skin contact (use gloves if handling large quantities); ensure ventilation in work areas to prevent inhalation of high-concentration vapors. In case of fire, use dry chemical powder or foam extinguishers (do not use water, as D5 is insoluble and may spread the fire).​