Silanes & Organosilanes Available — Bulk Only

(3-Chloropropyl)trimethoxysilane (CPTMS)

CPTMS
CAS 2530-87-2 · Formula C6H15ClO3Si · MW 198.72 g/mol

An organofunctional silane coupling agent that bonds mineral and glass surfaces to organic polymers, used in filled composites, textiles.

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HS Code
2931.90
At a Glance
Material Family
Silanes & Organosilanes
Record Type
Pure compound
Primary Role
Coupling / Adhesion Promotion · Crosslinking / Curing
Applications & Use Cases
  • Composite coupling: Couples mineral and glass fillers to organic resin matrices.
  • Adhesion promotion: Improves bond strength between inorganic substrates and polymers.
  • Silane intermediate: Reactive chloropropyl handle for downstream organosilane synthesis.
  • Surface treatment: Modifies fillers and textile goods for resin compatibility.
Physical Properties
Physical Description
Liquid; Colorless liquid
Vapor Pressure
0.39
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
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
2530-87-2
Molecular Formula
C6H15ClO3Si
Molecular Weight
198.72 g/mol
IUPAC Name
3-chloropropyl(trimethoxy)silane
PubChem CID
InChI Key
OXYZDRAJMHGSMW-UHFFFAOYSA-N
Synonyms & Trade Names
3-Chloropropyltrimethoxysilane (3-Chloropropyl)trimethoxysilane Silane, (3-chloropropyl)trimethoxy- 3-(Trimethoxysilyl)propyl chloride KBM 703 A 143 SH 6076 CPTMS cpd 3-chloropropyl(trimethoxy)silane CPS-M 3-Chloropropyltrimethyoxysilane Sila-Ace S 620 C6H15ClO3Si (3-Chloropropyl)trimethoxysilan Chloropropyltrimethoxysilane Silane (3-chloropropyl)tris(methoxy)-
Full Description

(3-Chloropropyl)trimethoxysilane (CPTMS, CAS 2530-87-2) is an organofunctional silane whose trimethoxysilyl group bonds to mineral and glass surfaces while the chloropropyl group anchors to organic polymers. It is used as a coupling agent in filled composites and treated textile goods, as an adhesion promoter, and as an intermediate for synthesizing other organosilicon compounds.

Regulatory & registration requirements

  • TSCA (US):
  • REACH (EU):
  • EC number: 219-787-9

Source: EPA TSCA Inventory (July 2025 release) · ECHA CHEM — retrieved 2026-07-12

Frequently Asked Questions

What is (3-chloropropyl)trimethoxysilane used for?

CPTMS is an organofunctional silane coupling agent. Its trimethoxysilyl group hydrolyzes to bond mineral and glass surfaces while the chloropropyl group anchors to organic polymers, so it functions as an adhesion promoter in filled composites and treated textile goods. It is also widely used as a reactive intermediate for synthesizing other organosilicon compounds via the chloropropyl handle.

What is the CAS number and molecular formula of CPTMS?

(3-Chloropropyl)trimethoxysilane has CAS number 2530-87-2 and molecular formula C6H15ClO3Si. It is classified under the Silanes & Organosilanes family.

How does CPTMS work as a coupling agent?

The three methoxy groups hydrolyze to silanols that condense onto hydroxylated inorganic surfaces such as silica, glass, and minerals. The terminal chloropropyl group remains available to react with or anchor to organic polymer matrices, bridging the inorganic filler and the resin to improve bond strength and reinforcement.

What is the HS code for CPTMS for import/export?

It classifies under HS 2931.90 — other organo-inorganic compounds (organo-silicon compounds). Confirm the destination-country tariff suffix with your customs broker; RawSource provides commercial documentation on bulk orders.

What bulk packaging and documentation does RawSource supply for CPTMS?

RawSource distributes CPTMS in industrial volumes (drums, totes, and IBCs) to manufacturers, with Certificate of Analysis and Safety Data Sheet provided per lot. Request a bulk quote with your target volume and packaging for current pricing and lead time.

What is the REACH and TSCA regulatory status of (3-Chloropropyl)trimethoxysilane (CPTMS)?

(3-Chloropropyl)trimethoxysilane (CPTMS) (CAS 2530-87-2) is subject to U.S. TSCA Inventory requirements; supplying it into the EU requires valid REACH registration ((EC) No 1907/2006). RawSource cannot verify a third-party supplier's registrations — buyers should require documented TSCA and REACH compliance for their jurisdiction and volume (EC 219-787-9).

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.