Industrial Manufacturing / Solution Family

Silane Coupling Agents

Bifunctional organosilanes that bond mineral fillers, glass, and metal to organic resins and rubber u2014 amino, epoxy, vinyl, mercapto, and sulfur-functional coupling agents.

Overview

Silane coupling agents are bifunctional organosilicon molecules that chemicallynbridge an inorganic surface (glass, mineral filler, metal oxide) and an organic polymern(resin or rubber). One end carries hydrolyzable alkoxy groups that bond to theninorganic surface; the other carries an organofunctional group u2014 amino, epoxy, vinyl,nmercapto, or sulfur u2014 that reacts with the polymer. Match that organofunctional group tonyour resin: amino for epoxies and phenolics, epoxy-silane for waterborne and epoxy systems,nsulfur-functional for silica-reinforced rubber.

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The alkoxy group determines handling. Trimethoxysilanes hydrolyze quickly and reactnreadily, which speeds cure but releases methanol; triethoxysilanes are slower and releasenethanol instead. That is the genuine trade-off across this family: reactivity againstnbyproduct. For most adhesion-promotion work, dose the silane at a low percentage of fillernweight and pre-hydrolyze or pre-blend per the substrate. Specify a trimethoxy grade whenncure speed matters and an ethoxy grade when the methanol byproduct is a concern.

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Sulfur-functional silanes serve rubber compounding specifically. Mercaptopropyl silane isnhighly reactive and couples silica filler to the elastomer for better reinforcement, but itsnreactivity can cause premature scorch during mixing. The blocked sulfide grade,nbis[3-(triethoxysilyl)propyl] disulfide (TESPD), trades some coupling activity for safer,nmore controllable processing. For tire and technical-rubber compounds, the disulfide isnusually the more forgiving starting point.

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Recommended Chemistries
15 materials
(3-Aminopropyl)silanetriol
CAS 58160-99-9
Coupling / Adhesion Promotion Quick view
(3-Chloropropyl)trimethoxysilane (CPTMS)
CAS 2530-87-2
Coupling / Adhesion Promotion Quick view
(3-Mercaptopropyl)trimethoxysilane (MPTMS)
CAS 4420-74-0
Mercapto silane (rubber coupling) Quick view
3-(2-Aminoethylamino)propyltrimethoxysilane (DAMO)
CAS 1760-24-3
Coupling / Adhesion Promotion Quick view
3-Aminopropyltriethoxysilane (APTES)
CAS 919-30-2
Amino silane coupling agent Quick view
3-Glycidoxypropylmethyldiethoxysilane (GPDMS)
CAS 2897-60-1
Coupling / Adhesion Promotion Quick view
3-Glycidoxypropyltriethoxysilane (GPTES)
CAS 2602-34-8
Coupling / Adhesion Promotion Quick view
3-Glycidoxypropyltrimethoxysilane (GPTMS)
CAS 2530-83-8
Epoxy silane coupling agent Quick view
3-Methacryloxypropyltrimethoxysilane (MPTMS)
CAS 2530-85-0
Coupling / Adhesion Promotion Quick view
Bis[3-(triethoxysilyl)propyl] Disulfide (TESPD)
CAS 56706-10-6
Sulfur-functional silane (silica-rubber coupling) Quick view
Bis[3-(triethoxysilyl)propyl] Tetrasulfide (TESPT)
CAS 40372-72-3
Coupling / Adhesion Promotion Quick view
Methyltris(methylethylketoxime)silane
CAS 22984-54-9
Coupling / Adhesion Promotion Quick view
N-(2-Aminoethyl)-3-aminopropylmethyldimethoxysilane (Diamino-Functional Silane)
CAS 3069-29-2
Coupling / Adhesion Promotion Quick view
Vinyltrimethoxysilane (VTMS)
CAS 2768-02-7
Vinyl silane (crosslinking & coupling) Quick view
Vinyltris(2-Methoxyethoxy)Silane
CAS 1067-53-4
Coupling / Adhesion Promotion Quick view
Where it's used
  • Adhesion promotion between inorganic fillers/substrates and organic resins in adhesives and sealants
  • Coupling agents for glass-fiber and mineral-filled composite manufacturing
  • Silica-reinforced rubber and tire compounding (sulfur-functional silanes)
  • Crosslinking and moisture-cure of polyethylene and other polyolefins (vinyl silane)
  • Primers and surface treatments to improve coating adhesion to metal and glass
Frequently asked questions
Which silane coupling agent should I use for my system?
Match the organofunctional end to your polymer. Amino silanes (e.g. APTES) are the general-purpose choice for epoxy, phenolic, and acrylic systems; epoxy silanes (GPTMS) suit epoxy and waterborne formulations; vinyl silanes crosslink polyethylene; and sulfur-functional silanes (mercapto or TESPD) couple silica filler in rubber. The inorganic end is alkoxy in all cases and bonds to glass, mineral filler, or metal oxide.
What is the difference between trimethoxy and triethoxy silanes?
Trimethoxysilanes hydrolyze and react faster, which speeds cure but releases methanol as the byproduct. Triethoxysilanes react more slowly and release ethanol instead. Choose a trimethoxy grade when cure speed is the priority and an ethoxy grade when the methanol byproduct is a concern for your process or jurisdiction.
Which silanes are used in silica-reinforced rubber and tires?
Sulfur-functional silanes. (3-Mercaptopropyl)trimethoxysilane is highly reactive and gives strong silica-to-rubber coupling but can scorch during mixing. Bis[3-(triethoxysilyl)propyl] disulfide (TESPD) is a blocked disulfide that trades some coupling activity for more controllable processing, which is why it is a common starting point for tire and technical-rubber compounds.
Does RawSource supply silane coupling agents in bulk?
Yes. RawSource sources amino (APTES), epoxy (GPTMS), vinyl (vinyltrimethoxysilane), mercapto, and sulfur-functional (TESPD) silanes for industrial manufacturing at bulk scale with full documentation. Send your substrate, resin system, and target volume for a bulk RFQ.
Disclaimer. Information on this page is provided for general reference and compiled from authoritative public sources (e.g. PubChem/ECHA). Values are typical and are not a guaranteed specification; the Certificate of Analysis (CoA) for the lot you purchase governs. Products are sold for industrial and professional use only. Nothing here is a medical, health, or efficacy claim. Always consult the current Safety Data Sheet (SDS) before handling, and confirm regulatory status, classification, and suitability for your application and jurisdiction.
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