Silanes & Organosilanes Available — Bulk Only

Methyltriethoxysilane (MTES)

CAS 2031-67-6 · Formula C7H18O3Si · MW 178.30 g/mol

A methyl alkoxysilane used to prime and bond inorganic surfaces. It is used as an adhesion and cohesion promoter and as a silane intermediate. It is also permitted as an inert ingredient in non-food pesticide products.

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UN Number
UN 1993
Hazard Class
Class 3
HS Code
2931.90
At a Glance
Material Family
Silanes & Organosilanes
Record Type
Pure compound
Primary Role
Coupling / Adhesion Promotion · Crosslinking / Curing
Functional Roles
METHYLTRIETHOXYSILANE
NOT REPORTED
Applications & Use Cases
  • Adhesion promoter: Improves bonding between resins or coatings and mineral and metal substrates.
  • Intermediate: Serves as a building block for siloxane and sol-gel chemistries.
  • Formulation additive: Permitted as an inert ingredient in non-food pesticide products.
Physical Properties
Physical Description
Liquid
Boiling Point
144.5 °C @760 [mm Hg]
Density
0.895 @ 20°C
Vapor Pressure
11.0 [mmHg]
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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DOT / UN Transport Classification
DOT hazard class 3 placard
UN / DOT NumberUN 1993
Hazard Class / DivisionClass 3
Proper Shipping NameFlammable liquids, n.o.s.

Transport classification per the UN Model Regulations / 49 CFR 172.101 Hazardous Materials Table. Confirm against the grade-specific SDS (Section 14) before shipping.

HS / Tariff Classification
Harmonized System (HS) Code — 6-digit international heading
2931 . 90
Chapter 29
Organic chemicals
Heading 29.31
Internationally harmonized (WCO HS)
Subheading 2931.90
6-digit international code — national tariff line adds further digits
Chemical Identity
CAS Number
2031-67-6
Molecular Formula
C7H18O3Si
Molecular Weight
178.30 g/mol
IUPAC Name
triethoxy(methyl)silane
INCI Name
METHYLTRIETHOXYSILANE
PubChem CID
InChI Key
CPUDPFPXCZDNGI-UHFFFAOYSA-N
Synonyms & Trade Names
Methyltriethoxysilane Triethoxymethylsilane Triethoxy(methyl)silane Methyl triethoxysilane Silane, triethoxymethyl- Triethoxysilylmethane ICI-EP 5850 SILANE, METHYLTRIETHOXY- MTES A 162 Methaneorthosiliconic acid, triethyl ester Union carbide A-162 Dynasylan MTES
Full Description

Methyltriethoxysilane (MTES, CAS 2031-67-6) is an ethoxy-functional organosilane that hydrolyzes to methyl-functional siloxane species. It is used as an adhesion and cohesion promoter and as a silane intermediate. It is also permitted as an inert ingredient in non-food pesticide products.

Frequently Asked Questions

What is methyltriethoxysilane?

Methyltriethoxysilane (MTES, CAS 2031-67-6, C7H18O3Si) is an ethoxy-functional organosilane in the silanes and organosilanes family. On contact with moisture its ethoxy groups hydrolyze and condense into methyl-functional siloxane species, making it useful as an adhesion/cohesion promoter and a silane intermediate.

What is methyltriethoxysilane used for?

It is used as an adhesion and cohesion promoter to improve bonding between resins or coatings and mineral and metal substrates, and as an intermediate building block for siloxane and sol-gel chemistries. It is also permitted as an inert ingredient in non-food pesticide formulations.

What is the difference between methyltriethoxysilane and methyltrimethoxysilane?

Both are trifunctional methylsilanes that build methylsiloxane networks, but MTES carries three ethoxy groups while methyltrimethoxysilane (MTMS, CAS 1185-55-3) carries three methoxy groups. The ethoxy version releases ethanol on hydrolysis and cures more slowly; the methoxy version releases methanol and is generally faster-reacting.

What is the HS code for methyltriethoxysilane?

Methyltriethoxysilane is classified under HS heading 2931.90 (other organo-inorganic compounds). Confirm the destination-country tariff subheading with your customs broker for import documentation.

How is bulk methyltriethoxysilane packaged and ordered?

RawSource supplies organosilanes such as MTES in bulk industrial packaging including drums and totes/IBCs to manufacturers and formulators. Because it is moisture-sensitive, it ships in sealed containers; request a current SDS and CoA and submit a bulk quote for volume pricing and MOQ rather than relying on a published list price.

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.