aozun
Siloxanes and silicones, dimethyl
Colorless, clear liquid
63148-62-9
(C₂H₆OSi)ₙ (repeat-unit notation)
Variable; depends on polymer chain length
Insoluble in water
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Product Description
Dimethicone is a clear, colorless organosilicon polymer widely used as a sensory modifier, emollient, conditioning agent, film former, lubricant and foam-control ingredient. It is also known as polydimethylsiloxane, PDMS or dimethyl silicone fluid.
Unlike a conventional small molecule, Dimethicone is a family of linear siloxane polymers with different chain lengths. Its molecular weight, viscosity, volatility, spreadability and film-forming performance therefore depend on the selected grade.
We supply Dimethicone in multiple viscosity grades for personal care, pharmaceutical, formulation and industrial applications. Final viscosity, purity, cyclic-siloxane limits, packaging and regulatory documentation are confirmed against the applicable specification and Certificate of Analysis.
INCI name: Dimethicone
Chemical name: Polydimethylsiloxane
Abbreviation: PDMS
Common CAS number: 9006-65-9
Alternative CAS used for some grades: 63148-62-9
Chemical type: Organosilicon polymer
Appearance: Clear, colorless liquid
Odor: Essentially odorless
Water solubility: Insoluble
Typical commercial form: Silicone fluid
Primary role: Specialty functional ingredient
Dimethicone consists primarily of repeating dimethylsiloxane units with a silicon-oxygen backbone and methyl side groups. A simplified repeat unit may be written as:
[–Si(CH₃)₂–O–]ₙ
Because “n” varies, Dimethicone does not have one fixed molecular weight. Higher polymer chain length generally produces higher viscosity, slower spreading and a more persistent surface film.
Commercial Dimethicone can range from a very light, mobile fluid to an extremely viscous silicone gum. Buyers should therefore never specify only the INCI name or CAS number; viscosity and product form are essential purchasing information.
Property | General reference |
|---|---|
INCI name | Dimethicone |
Chemical name | Polydimethylsiloxane |
Common CAS number | 9006-65-9 |
Alternative CAS reference | 63148-62-9 |
Appearance | Clear, colorless liquid |
Odor | Essentially odorless |
Water solubility | Insoluble |
Ionic character | Nonionic |
Specific gravity | Commonly approximately 0.90–0.98, depending on grade |
Refractive index | Commonly approximately 1.39–1.41 |
Viscosity range | From very low-viscosity fluid to silicone gum |
Volatility | Depends strongly on molecular weight and viscosity |
Combustibility | Flash point depends on grade; consult the current SDS |
Chemical family | Organosilicon polymer or silicone fluid |
These are general characteristics rather than contractual specifications. The Technical Data Sheet and Certificate of Analysis for the selected viscosity grade take precedence.
Viscosity is the most important variable when selecting a Dimethicone grade. It affects spreading speed, lubricity, cushion, film persistence, gloss and manufacturing behavior.
Nominal viscosity | General sensory and processing profile | Typical application direction |
0.65–10 cSt | Very light, fast spreading, low residue; some grades have measurable volatility | Light skin feel, color cosmetics, antiperspirants, carriers |
20–100 cSt | Light emolliency with good spreading and moderate lubricity | Serums, lotions, hair care, makeup |
200–500 cSt | Balanced slip, cushion and film formation | Creams, conditioners, primers and foundations |
1,000–5,000 cSt | Richer feel, stronger lubrication and more persistent film | Hair serums, barrier formulations, richer creams |
10,000–30,000 cSt | High substantivity and strong conditioning; slower processing | Intensive hair care and specialty protective formulations |
Above 30,000 cSt | Extremely viscous or gum-like, difficult to pump without suitable equipment | Specialty films, high-conditioning blends and industrial uses |
These ranges describe general trends. Sensory performance also depends on concentration, emulsifier, oil phase, powder loading and other formulation ingredients.
Dimethicone 350 cSt is a widely used medium-viscosity grade because it offers a practical balance between spreadability and film persistence.
It can provide:
Smooth application
Reduced tack and drag
Improved slip
Soft after-feel
Moderate gloss
Water repellency
Reduced whitening during cream rub-in
Improved hair conditioning and manageability
Easier pumping than very high-viscosity grades
It is not automatically the best grade for every formula. Lightweight serums may require lower viscosity, while richer hair treatments or protective films may benefit from higher viscosity.
Dimethicone viscosity may be reported in centistokes, centipoise or millipascal-seconds.
cSt measures kinematic viscosity.
cP measures dynamic viscosity.
mPa·s is numerically equivalent to cP.
Dynamic viscosity is related to kinematic viscosity through the fluid density.
Because Dimethicone density varies by grade, a value in cSt should not be copied directly into a cP specification without confirming the measurement basis.
The test temperature must also be stated. Dimethicone viscosity is commonly measured at 25°C, but other temperatures may be used.
Parameter | Why it matters |
Viscosity at defined temperature | Confirms polymer grade and processing behavior |
Appearance and clarity | Supports product identification and formulation aesthetics |
Color | Important for transparent and light-colored formulations |
Refractive index | Supports identity and batch consistency |
Specific gravity | Useful for dosing, conversion and viscosity comparison |
Volatile content | Indicates low-molecular-weight or processing residues |
D4 content | Relevant to regulatory and customer requirements |
D5 content | Relevant to regulatory and environmental requirements |
D6 content | Frequently included in cyclic-siloxane declarations |
Acid value or acidity | May be controlled for sensitive formulations |
Heavy metals | Important for cosmetic and pharmaceutical qualification |
Microbiological limits | May be required for certain personal-care supply chains |
Active content | Essential for emulsions, blends and compounded products |
For cosmetic purchasing, the specification should clearly distinguish between a pure Dimethicone fluid and a formulation containing Dimethicone.
Pure Dimethicone fluid is normally a clear, water-insoluble silicone liquid with a defined viscosity. It is commonly supplied at or near 100% active content.
This is the standard form used when formulators want direct control over the silicone level and oil-phase composition.
A Dimethicone emulsion contains silicone droplets dispersed in water with an emulsifier or stabilizing system.
It may be easier to add to water-based products, but its active Dimethicone content is lower than 100%. Emulsion type, particle size, surfactant system and preservation must be evaluated.
A gum blend contains very high-molecular-weight Dimethicone or related silicone gum dispersed in a lower-viscosity carrier.
It can provide stronger conditioning, film formation, substantivity and hair manageability than a standard medium-viscosity fluid.
Dimethiconol is a hydroxyl-terminated silicone polymer with a different INCI identity. It may be supplied as a fluid, gum or dispersion and should not automatically be substituted for Dimethicone.
Dimethicone Crosspolymer is a crosslinked silicone elastomer. It can provide powdery texture, oil absorption, thickening and a soft-focus sensory effect.
It is structurally and functionally different from linear Dimethicone fluid.
Simethicone generally consists of polydimethylsiloxane combined with finely divided silica. It is used in antifoaming applications and certain pharmaceutical products.
Dimethicone and Simethicone are related but are not interchangeable names.
Dimethicone is valued because it can modify both application feel and surface performance.
Depending on viscosity and concentration, it may provide:
Slip and lubricity
Improved spreadability
Reduced tackiness
Softer skin feel
Hair conditioning
Easier wet and dry combing
Frizz control
Gloss enhancement
Water repellency
Protective film formation
Pigment wetting and dispersion support
Reduced cream whitening during application
Foam control
Release and surface lubrication
Performance must be confirmed in the final formulation because interaction with oils, waxes, surfactants, powders and polymers can significantly change the result.
Dimethicone is used in personal care and industrial formulations when controlled slip, conditioning, water resistance, surface modification or foam management is required.
In creams, lotions, serums and balms, Dimethicone can improve spreadability, reduce tack and leave a smooth surface feel.
Potential applications include:
Facial moisturizers
Body lotions
Hand creams
Barrier creams
Facial serums
Eye-area products
Shaving products
After-sun formulations
Hand and foot care
The selected viscosity influences whether the formula feels light and fast spreading or rich and protective.
Dimethicone can deposit a lubricating film on the hair surface, improving smoothness, combability, shine and manageability.
Typical products include:
Rinse-off conditioners
Leave-in conditioners
Hair serums
Anti-frizz products
Heat-styling products
Hair masks
Shine sprays
Split-end treatments
Higher-viscosity Dimethicone can provide stronger substantivity but may require careful emulsification or dispersion to avoid uneven deposition.
Dimethicone improves slip, pigment distribution, water resistance and sensory elegance in color-cosmetic formulations.
Applications include:
Foundations
Primers
Concealers
Lip products
Cream blushes
Mascaras
Eye products
Long-wear makeup
Pressed and loose powder binders
Refractive index, viscosity and compatibility with pigments and other oils should be evaluated during formulation development.
In sunscreen formulations, Dimethicone may improve spreading, reduce tack, support water resistance and enhance the uniformity of the applied film.
Use of Dimethicone does not itself establish an SPF or water-resistance claim. Finished products require appropriate performance and regulatory testing.
Low- and medium-viscosity grades may provide spreading, reduced greasiness and improved sensory properties in sticks, roll-ons, creams and anhydrous systems.
Compatibility with antiperspirant salts, waxes and volatile carriers should be confirmed.
Appropriately qualified Dimethicone may be used as a pharmaceutical excipient or active skin-protectant ingredient in specific markets.
Pharmaceutical use requires the correct grade, pharmacopoeial specification, manufacturing controls and regulatory documentation. Cosmetic-grade material must not automatically be represented as pharmaceutical grade.
Dimethicone can reduce foam in selected water-based and industrial processes. Effective performance depends on dispersion, droplet size, carrier system and the chemistry of the foaming medium.
A compounded antifoam or silicone emulsion may perform better than pure Dimethicone when rapid dispersion in water is required.
Industrial grades may be used for:
Mold release
Surface lubrication
Polishes
Textile treatment
Rubber and plastic processing
Electrical and mechanical applications
Protective surface films
Heat-transfer or damping applications
Industrial-grade Dimethicone must not be used in cosmetic, food or pharmaceutical products without appropriate qualification.
Pure Dimethicone is insoluble in water and is normally incorporated into an oil, silicone or emulsified phase.
During formulation development, evaluate:
Dimethicone viscosity
Required sensory profile
Oil-phase compatibility
Emulsifier selection
Mixing and shear
Addition temperature
Target droplet size
Powder and pigment wetting
Formula stability
Packaging compatibility
Finished-product application method
Low-viscosity grades are generally easier to disperse and pump. High-viscosity grades may require pre-blending, heating where appropriate or specialized pumping and mixing equipment.
Supplier formulation guidance should be treated as a starting point rather than a substitute for stability, compatibility and performance testing.
Dimethicone is compatible with many silicone fluids, hydrocarbons, esters, waxes and cosmetic oils, but compatibility is not universal.
It is generally insoluble in:
Water
Glycerin
Propylene glycol
Many highly polar solvents
Phase separation can occur when Dimethicone is added without a suitable carrier or emulsification system. Always perform bench testing before production scale-up.
Commercial Dimethicone can contain residual low-molecular-weight cyclic siloxanes from manufacturing. Buyers may need defined limits for:
D4: Octamethylcyclotetrasiloxane
D5: Decamethylcyclopentasiloxane
D6: Dodecamethylcyclohexasiloxane
Requirements vary by market, product type and customer standard. A general statement such as “cosmetic grade” does not replace a numerical D4, D5 and D6 specification.
For products intended for the European market or multinational brands, request a current cyclic-siloxane declaration and verify the applicable regulatory requirements for the finished product.
The INCI name Dimethicone identifies the cosmetic ingredient but does not establish:
Product purity
Viscosity
Pharmaceutical compliance
Food-contact status
D4, D5 or D6 limits
Country-specific regulatory acceptance
Suitability for leave-on or rinse-off use
Finished-product claim support
Depending on the application, buyers may request:
Cosmetic-grade declaration
INCI confirmation
USP or other pharmacopoeial compliance
REACH information
D4/D5/D6 declaration
Animal-origin statement
Vegan statement
Allergen statement
GMO statement
Residual-solvent statement
Heavy-metal data
Microbiological information
Country-specific inventory status
All compliance claims should match the exact supplied grade.
Depending on viscosity and quantity, Dimethicone may be supplied in:
Small containers
HDPE pails
Metal or plastic drums
Intermediate bulk containers
Bulk supply systems
High-viscosity grades may require wider openings, drum heaters, positive-displacement pumps or other suitable transfer equipment.
Store Dimethicone:
In the original tightly closed container
In a clean, dry and ventilated area
Away from contamination and incompatible materials
Within the supplier’s recommended temperature range
Protected from prolonged exposure to excessive heat
With cosmetic and pharmaceutical grades segregated from industrial materials
Dimethicone spills can create an extremely slippery surface. Contain and clean spills promptly using an approved procedure.
Depending on the grade and market, available documentation may include:
Certificate of Analysis
Safety Data Sheet
Technical Data Sheet
Product specification
INCI statement
Country-of-origin statement
Manufacturing-process summary
D4/D5/D6 declaration
REACH or inventory-status statement
Animal-origin statement
Vegan statement
Allergen statement
GMO statement
Heavy-metal data
Microbiological statement
Pharmacopoeial compliance statement
Change-notification policy
Packaging specification
Confirm required documents before placing an order.
For a faster and more accurate quotation, provide:
INCI name or chemical name
Required viscosity in cSt, cP or mPa·s
Test temperature
Cosmetic, pharmaceutical or industrial grade
Pure fluid, emulsion or blend requirement
Required D4, D5 and D6 limits
Maximum volatile content
Required refractive-index or density range
Packaging size
Order quantity and annual demand
Delivery country, city or port
Intended application
Required regulatory and quality documents
Dimethicone is a family of linear polydimethylsiloxane polymers used for slip, conditioning, film formation, water repellency, lubrication and foam control.
Dimethicone is an organosilicon polymer. It contains an inorganic silicon-oxygen backbone with organic methyl groups and is commercially classified with organic silicone specialty chemicals.
Dimethicone is generally a specialty or fine chemical ingredient rather than a chemical intermediate. It is commonly used directly for its functional properties in finished formulations.
Dimethicone is a common type of silicone oil, but “silicone oil” is a broader term that can include other silicone structures and functional groups.
No. Dimethicone is a polymer family, and molecular weight varies with chain length. Commercial grades are usually selected by viscosity rather than a single molecular weight.
The 100 cSt grade is lighter and spreads more quickly. The 1,000 cSt grade is thicker, provides greater cushion and forms a more persistent surface film.
No. Pure Dimethicone is insoluble in water. It requires a suitable emulsifier, dispersion system or pre-made emulsion for incorporation into water-based formulations.
Volatility depends on molecular weight and viscosity. Very low-viscosity grades can have more volatility, while conventional medium- and high-viscosity Dimethicone fluids are generally considered non-volatile.
No. Dimethiconol is normally hydroxyl-terminated and has a different INCI identity and formulation behavior.
No. Simethicone generally combines polydimethylsiloxane with finely divided silica. It is a separately specified material.
There is no universal best viscosity. Low viscosities provide lighter spreading, medium viscosities such as 350 cSt balance slip and film formation, and high viscosities provide stronger substantivity and conditioning.
Not automatically. Pharmaceutical use requires the correct grade, applicable pharmacopoeial compliance, quality system and intended-use documentation.
Send us your required viscosity, grade, cyclic-siloxane limits, packaging, quantity and delivery destination. We will confirm the applicable specification, documentation and commercial terms.
For personal-care applications, include the intended product type and target sensory profile. For pharmaceutical or regulated applications, provide the required pharmacopoeial and quality-system requirements.