Specialty Additives Available — Bulk Only

Dimethiconol

CAS 31692-79-2 · Formula C2H8O2Si · MW 92.17 g/mol

A silanol-terminated polydimethylsiloxane gum used as a film-former, conditioning agent, and antifoam in personal care and industrial applications.

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HS Code
3910.00
At a Glance
Material Family
Specialty Additives
Record Type
Pure compound
Primary Role
Defoaming / Foam Control · Emolliency
Functional Roles
DIMETHICONOL
ANTIFOAMINGMOISTURISINGSKIN CONDITIONING - EMOLLIENT
Industries Served
Applications & Use Cases
  • Hair conditioning: Deposits a smooth film for shine, slip and detangling.
  • Skin emollient: Softens and conditions in skin-care emulsions.
  • Film former: Builds a water-repellent silicone film on hair and skin.
  • Antifoam: Controls foam in formulation and process streams.
Safety & Handling
Full SDS available on request

A grade-specific Safety Data Sheet (SDS) — with the complete hazard classification, handling precautions, and transport information — is supplied with every shipment and available on request. Confirm all safety and regulatory details against the SDS for your specific grade.

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HS / Tariff Classification
Harmonized System (HS) Code — 6-digit international heading
3910 . 00
Chapter 39
Plastics and articles thereof
Heading 39.10
Internationally harmonized (WCO HS)
Subheading 3910.00
6-digit international code — national tariff line adds further digits
Chemical Identity
CAS Number
31692-79-2
Molecular Formula
C2H8O2Si
Molecular Weight
92.17 g/mol
IUPAC Name
dihydroxy(dimethyl)silane
INCI Name
DIMETHICONOL
PubChem CID
InChI Key
XCLIHDJZGPCUBT-UHFFFAOYSA-N
Synonyms & Trade Names
DIMETHYLSILANEDIOL Silanediol, dimethyl- Silanediol, 1,1-dimethyl- dihydroxy(dimethyl)silane 1,1-Dimethylsilanediol Polydimethylsiloxane, hydroxy terminated, M.W. 4200 1,1-Dimethylsilanediol >90% Dimethiconol Dihydroxydimethylsilane C2H8O2Si Dihydroxydimethylsilane; Dimethyldihydroxysilane; Dimethylsilanediol; Dimethylsilanediol # Simethicone Impurity 10 Si(OH)2Me2
Full Description

Dimethiconol is the INCI name for a silanol- (hydroxyl-) terminated polydimethylsiloxane — a high-molecular-weight silicone whose chains end in reactive –OH groups instead of the inert methyl caps of standard dimethicone. Those terminal silanols give it gum-like body and strong film-forming character, which is why it is a workhorse shine, slip and conditioning agent in hair and skin formulation and a film former and antifoam in industrial systems. It is identified by CAS 31692-79-2 (PubChem) and is most often supplied either as a high-viscosity gum or pre-dispersed in a flowable carrier such as low-viscosity dimethicone or cyclopentasiloxane — the familiar “dimethiconol and dimethicone” blends.

What is dimethiconol?

Dimethiconol is a polydimethylsiloxane (PDMS) polymer terminated with silanol (–Si–OH) groups rather than trimethylsilyl caps. The reactive end groups raise the effective molecular weight and let the polymer build a continuous, substantive film, so dimethiconol behaves more like a silicone gum than a free-flowing oil. Because a true gum is hard to pump and emulsify, it is usually delivered to formulators as a blend — dispersed in low-viscosity dimethicone or in volatile cyclopentasiloxane — which carries the gum into a formula and then leaves the high-shine dimethiconol film behind as the carrier spreads or flashes off.

Applications by sector

Personal care — hair. Dimethiconol deposits a smooth, light-reflecting film that adds gloss and slip and helps lay down frizz and flyaways in conditioners, masks, leave-ins, serums and two-in-one systems. This describes formulation behavior — film, slip and optics — and is not a hair- or skin-health claim. Personal care — skin. It contributes a water-repellent emollient film and a silky, non-greasy after-feel in lotions, primers and color cosmetics. It is almost always formulated as a dimethiconol/dimethicone or dimethiconol/cyclopentasiloxane blend so the gum can be metered and emulsified. Industrial. The same film-forming, surface-active behavior makes dimethiconol useful as a film former and as a defoaming/antifoam silicone in non-aqueous and aqueous systems.

Dimethiconol vs dimethicone

Both are polydimethylsiloxane silicones; the difference is the chain end group, and it changes everything downstream.

Dimethicone Dimethiconol
End groups Methyl (inert, trimethylsilyl) Silanol –OH (reactive)
Typical form Free-flowing fluid across a viscosity ladder High-viscosity gum, usually supplied as a carrier blend
Character Spreading, slip, lubrication, even film Film-forming, substantive shine and conditioning
Typical use Carrier, slip/feel modifier, lubrication, release Shine and frizz-control film, durable conditioning, film former

For the straight dimethicone fluids by viscosity, see the silicone oil viscosity guide and the full bulk silicone supplier hub.

Forms and grades

Specify the form and the dimethiconol content on your RFQ. Dimethiconol is supplied as a high-viscosity gum for formulators who disperse it themselves, or — more commonly — as a ready-to-use blend in a stated carrier (for example a dimethiconol-and-dimethicone fluid at a given blend viscosity). Confirm the carrier, the active dimethiconol level and the target viscosity for your process; the CoA documents the grade you receive.

Handling and documentation

Dimethiconol is water-insoluble and is handled in the oil/silicone phase. Each lot ships with a Certificate of Analysis (CoA); request the Safety Data Sheet (SDS) for physical-property, flammability and handling data, which are sourced from the SDS rather than reproduced here.

Bulk supply and RFQ

RawSource supplies dimethiconol — as a gum or as a dimethicone/cyclopentasiloxane blend — in drums and totes from domestic US stock for short lead times, to personal-care and silicone-blend manufacturers. Pricing is quote-based on grade, carrier, active level, volume and packaging. Related silicones: dimethicone (PDMS fluid), cyclopentasiloxane, phenyl trimethicone, amodimethicone.

Typical Properties

Typical reference values, not a specification; the Certificate of Analysis (CoA) for the lot governs.

Property Typical Value
INCI Name Dimethiconol
CAS Number 31692-79-2
Chemical type Silanol (hydroxyl)-terminated polydimethylsiloxane (PDMS)
Appearance Clear to translucent fluid or gum (clear flowable liquid as a carrier blend)
Molecular weight / viscosity Grade-dependent — pourable fluids to high-viscosity gums
Solubility Insoluble in water; miscible with silicones and many organic solvents
Flammability / handling Refer to the current SDS

Frequently Asked Questions

What is dimethiconol used for?

Dimethiconol (CAS 31692-79-2) is a silanol-terminated polydimethylsiloxane used in personal-care formulation as a shine, slip and conditioning film former for hair and skin, and in industrial systems as a film former and antifoam. It is usually formulated as a dimethiconol/dimethicone or dimethiconol/cyclopentasiloxane blend.

What is the difference between dimethiconol and dimethicone?

Both are polydimethylsiloxane silicones, but dimethiconol is hydroxyl-terminated (it carries reactive –OH end groups) whereas dimethicone is methyl-terminated. The terminal silanols give dimethiconol higher-molecular-weight, gum-like, film-forming behavior used for shine and durable conditioning, while dimethicone is a free-flowing fluid used for spreading, slip and lubrication.

Is dimethiconol water soluble?

No. Dimethiconol is a silicone fluid/gum and is not water soluble; it is used in the oil/silicone phase and deposits a water-repellent film. Refer to the SDS for physical-property and handling data.

How is dimethiconol supplied — gum or blend?

Both. It is available as a high-viscosity gum for formulators who disperse it themselves, and more commonly as a ready-to-use blend in a low-viscosity dimethicone or volatile cyclopentasiloxane carrier. Specify the carrier and the active dimethiconol content on the RFQ.

What is the CAS number and formula of dimethiconol?

Dimethiconol is identified by CAS 31692-79-2 (PubChem CID 14014); the indexed repeat-unit formula is C2H8O2Si. It is a polymer, so the molecular weight and viscosity are grade-dependent — specify the target grade when ordering.

How is bulk dimethiconol supplied and quoted?

RawSource supplies dimethiconol in drums and totes from domestic US stock, with CoA and SDS per lot. Pricing is quote-based on grade, carrier, active level, volume and packaging; request a current bulk quote.

Disclaimer. Information on this page — including properties, identifiers, hazard, transport (DOT/UN) and tariff (HS) classifications, and applications — is provided for general reference and is compiled from authoritative public sources (e.g. PubChem/ECHA, 49 CFR 172.101, the Harmonized Tariff Schedule). Values are typical and are not a guaranteed specification; the Certificate of Analysis (CoA) for the lot purchased governs. Products are sold for industrial and professional use only. Nothing here is a medical, health, or efficacy claim or advice. Always consult the current Safety Data Sheet (SDS) before handling, storage, transport or disposal, and confirm regulatory status, classification and suitability for your application and jurisdiction. Hazard, transport and tariff classifications must be verified for your specific shipment. RawSource makes no warranty, express or implied, and assumes no liability for use of this information. Trademarks. Third-party trademarks and brand names are the property of their respective owners; any reference is nominative — used only to identify a comparable product — and does not imply affiliation with, sponsorship by, or endorsement by the trademark owner.