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Vinyltriethoxysilane is a vinyl-functional organosilane supplied as a clear, colorless monomeric liquid with three hydrolyzable ethoxy groups.
Its established applications include moisture-crosslinkable polyethylene, inorganic surface modification, silane coupling, and the preparation of functional polymers and hybrid materials.
Its distinctive function is to combine an organic reactive vinyl group with silicon-bound ethoxy groups that can hydrolyze and condense, enabling connections between organic polymers and inorganic structures.
CAS Number: 78-08-0
EC Number: 201-081-7
Molecular Formula: C8H18O3Si
Molecular Weight: 190.32 g/mol
Synonyms: Vinyltriethoxysilane, Triethoxyvinylsilane, Triethoxy(vinyl)silane, Ethenyltriethoxysilane, Ethenyl(triethoxy)silane, Triethoxyvinylsilicane, Silane ethenyltriethoxy, Silane triethoxyvinyl, (Triethoxysilyl)ethylene, O,O′,O″-Triethylvinylsilanetriol, VTES, VTEOS, VTEO, Vinyl Triethoxy Silane, Vinyl-Triethoxysilane, Vinyltriethoxy Silane, Vinyltri(ethoxy)silane, Vinyltriethoxy-silane, Triethoxyvinylsilane, Triethoxy Vinyl Silane, Triethoxyvinyl Silane, Triethoxy(vinyl)silane, Triethoxy(vinyl)-silane, Ethenyltriethoxysilane, Ethenyl Triethoxy Silane, Ethenyl(triethoxy)silane, Ethenyl-Triethoxysilane, Silane Ethenyltriethoxy, Silane Triethoxyvinyl, Silane Vinyltriethoxy, Silane Vinyl Triethoxy 1-151, (Triethoxysilyl)ethylene, Triethoxysilyl Ethylene, O,O′,O′′-Triethylvinylsilanetriol, O,O′,O′′-Triethyl Vinylsilanetriol, Tri(Ethoxo)(Vinyl)Silane, Ethenyltriethyloxy-Silane, Triethoxyvinylsilicane, Triethoxyvinyl Silicane, Vinyltriethoxysilane [INCI], VTES, VTEO, VTS-E, Silane A-151, A-151 Silane, A 151, Union Carbide A-151, Dynasylan VTEO, Polyscience VTES, KBE 1003, KBE-1003, JH-V151, NV 1107, CV-4910, FS-3827, V0044, CAS 78-08-0, EC 201-081-7, EINECS 201-081-7, UNII 8V1TKX755V, UNII-8V1TKX755V
APPLICATIONS
Moisture-crosslinkable polyethylene
Vinyltriethoxysilane introduces hydrolyzable silane functionality into polyethylene through peroxide-initiated grafting during melt processing.
The vinyl group participates in the grafting reaction, attaching silicon-containing functionality to the polymer rather than merely dispersing a liquid additive within it.
The grafted material can subsequently undergo moisture-driven reactions that connect polymer chains through siloxane bonds.
Vinyltriethoxysilane enables separation of polymer shaping from the final crosslinking stage.
The grafted polyethylene can retain thermoplastic processability before sufficient moisture curing develops the network.
This sequence allows extrusion or other shaping operations to precede the formation of the crosslinked structure.
Vinyltriethoxysilane-derived crosslinking requires moisture access to the grafted silane groups.
Water or steam treatment can accelerate curing, while ambient moisture can also participate under suitable conditions.
The curing schedule therefore depends on the formulation and article geometry rather than a single universal treatment time.
Filled polyethylene composites
Vinyltriethoxysilane has been investigated in crosslinked high-density polyethylene composites containing organomodified nanoclay.
In these systems, silane chemistry and filler incorporation jointly influence the network and the resulting material structure.
The composite cannot be assessed solely from the amount of silane added because filler content can alter the extent of crosslinking.
Vinyltriethoxysilane-based nanoclay research demonstrates that increasing filler loading does not necessarily increase gel content.
Published work reports reduced crosslinking in the presence of clay and with increasing clay concentration under the studied conditions.
This distinction matters when developing filled compounds because reinforcement and network formation are related but separate contributions to performance.
Silica surface functionalization
Vinyltriethoxysilane modifies silica by introducing vinyl-bearing organosilicon functionality at its surface.
Hydrolysis produces silanol groups capable of condensation with accessible surface hydroxyl groups and with neighboring silane-derived species.
The resulting treatment changes the chemical character of the interface while retaining vinyl functionality for subsequent reactions.
Vinyltriethoxysilane treatment of silica requires control over surface attachment and silane self-condensation.
A deposited layer can contain both surface-associated species and condensed siloxane structures, depending on the treatment conditions.
Consequently, the quantity applied does not by itself establish the number of accessible vinyl groups or the extent of attachment to the substrate.
Reactive platforms for further surface modification
Vinyltriethoxysilane can furnish vinyl-functional silica as an intermediate for additional polymer attachment.
Published research describes its role in introducing reactive groups before ultraviolet-driven grafting of poly(ethylene glycol) and poly(propylene glycol).
This approach separates initial mineral functionalization from the later introduction of polymer segments that determine the modified surface behavior.
Vinyltriethoxysilane’s contribution in such a sequence is to create a chemically addressable interface.
The subsequent grafted polymer, its coverage, and its interaction with the surrounding medium determine the final surface properties.
The starting silane should therefore be distinguished from the completed polymer-modified particle.
Hybrid sol–gel materials
Vinyltriethoxysilane acts as an organically substituted precursor in hydrolysis and condensation processes.
Its ethoxy groups participate in the development of silicon–oxygen structures, while its vinyl substituent supplies an organic component.
This combination permits the preparation and study of materials that connect inorganic network chemistry with organic functionality.
Vinyltriethoxysilane differs structurally from tetraethoxysilane because one silicon substituent is a vinyl group rather than a fourth hydrolyzable ethoxy group.
This difference changes the available connectivity and influences the development of condensed structures.
Comparative sol–gel studies consequently examine the two precursors separately rather than treating them as interchangeable sources of identical networks.
Vinyltriethoxysilane does not invariably produce a macroscopic gel after hydrolysis.
Research under particular acidic, excess-water conditions found that the precursor did not gel even though condensation occurred.
Successful hybrid-material design therefore requires attention to formulation and reaction conditions rather than assuming that three hydrolyzable groups guarantee gel formation.
Functional latex and copolymer research
Vinyltriethoxysilane has been investigated as a functional comonomer in vinyl acetate emulsion polymerization.
Its vinyl group offers a route for introducing silicon-containing functionality into an organic polymer, while its ethoxy groups remain subject to hydrolysis and condensation.
The interaction between these reaction pathways influences the developing latex microstructure.
Vinyltriethoxysilane’s behavior in a latex cannot be predicted simply from the behavior of vinyltrimethoxysilane or vinylsilanetriol.
A comparative study found that the vinyltriethoxysilane-containing latex did not develop significant crosslinking before or after drying under the investigated conditions.
This result establishes a formulation-specific limitation and prevents an automatic claim that any vinylsilane addition creates a strongly crosslinked film.
Vinyltriethoxysilane has also appeared in research on modified vinyl acetate–vinyl ester latex systems.
Semi-continuous seeded polymerization provides a route for introducing the silane alongside other functional monomers.
These studies concern engineered copolymer formulations, so their outcomes should not be assigned to the neat silane independently of the other ingredients.
Plasma-assisted polyethylene surface modification
Vinyltriethoxysilane has been grafted onto ultrahigh-molecular-weight polyethylene through plasma-assisted surface treatment.
This method addresses the difficulty of introducing covalently associated functionality onto an otherwise chemically resistant polyethylene surface.
The treatment changes the outer interface without requiring the same bulk melt-grafting process employed in moisture-crosslinkable polyethylene.
Vinyltriethoxysilane-based plasma research reports changes in surface roughness and water wettability after treatment.
Spectroscopic characterization identified the introduced surface functionality, linking the observed behavior to the modification process.
This remains a specialized surface-engineering application rather than evidence of unrestricted suitability for finished medical devices.
Sulfur-containing coupling-agent research
Vinyltriethoxysilane participates in research routes that combine it with sulfur through inverse vulcanization.
The resulting sulfur-containing materials have been investigated as interfacial coupling agents for silica-filled rubber composites.
Their design brings alkoxysilane functionality together with sulfur-containing structures within a modified coupling material.
Vinyltriethoxysilane-derived products in this research influence silica dispersion and filler–rubber interfacial adhesion.
The reported effects belong to the synthesized sulfur-containing product and the tested composite formulation.
They should not be interpreted as showing that neat vinyltriethoxysilane duplicates every function of a conventional sulfur-bearing rubber coupling agent.
Sealants and moisture management
Vinyltriethoxysilane appears in technical applications involving silicone formulations, sealants, and electronic encapsulating materials.
Its hydrolyzable groups can consume moisture during controlled reactions, making it relevant to moisture management in compatible formulations.
The resulting ethanol and condensed silane species become part of the formulation chemistry and must be considered alongside the intended curing system.
Vinyltriethoxysilane’s role depends on the other reactive components and the moisture already present.
A moisture-scavenging function is distinct from adhesion promotion or participation in network formation, even when more than one role occurs in a formulation.
Application to electronic encapsulation does not by itself establish a universal electrical specification or compatibility with every component material.
DESCRIPTION
Chemical identity and structure
Vinyltriethoxysilane is a discrete organosilicon molecule containing one vinyl group and three ethoxy groups attached to silicon.
Its condensed structural formula is CH2=CHSi(OC2H5)3.
The molecular formula and molecular weight describe the unhydrolyzed monomer rather than a solution, siloxane oligomer, or finished polymer.
Vinyltriethoxysilane contains a silicon–carbon bond connecting the vinyl substituent to silicon.
The ethoxy substituents instead connect through silicon–oxygen bonds and provide the hydrolyzable portion of the molecule.
This arrangement creates two chemically different routes for further reaction within a single starting material.
Hydrolysis and condensation
Vinyltriethoxysilane reacts with water by replacing ethoxy groups with silanol groups and releasing ethanol.
Hydrolysis can proceed through partially hydrolyzed intermediates rather than immediately converting every molecule into a fully hydrolyzed species.
The composition of the reacting liquid therefore changes with time and depends on the reaction environment.
Vinyltriethoxysilane-derived silanols can subsequently condense to create silicon–oxygen–silicon bonds.
Condensation competes with the persistence of individual hydrolyzed species and can generate increasingly complex molecular structures.
A prepared hydrolysate consequently differs from the neat starting monomer in composition and potential application behavior.
Vinyltriethoxysilane hydrolysis has been studied under neutral, acidic, and basic conditions in mixed solvent media.
Both acidity and basicity can strongly affect hydrolysis and intermolecular condensation.
These effects explain why a treatment solution cannot be characterized adequately by silane concentration alone.
Organic reaction pathway
Vinyltriethoxysilane’s carbon–carbon double bond provides a reaction pathway separate from ethoxy-group hydrolysis.
Radical grafting or suitable copolymerization conditions can connect that organic functionality to a polymer structure.
The presence of the double bond does not imply immediate attachment to every resin merely through mixing.
Vinyltriethoxysilane can therefore encounter competing chemical events in aqueous polymerization.
The organic group may participate in polymer formation while the silicon-bound groups undergo hydrolysis or condensation.
Comparative latex research shows that the identity of the alkoxy substituents materially affects the resulting crosslinking behavior.
Interfacial behavior
Vinyltriethoxysilane surface treatments depend on the chemical state of the substrate and the structure of the deposited layer.
Research on films formed at silica interfaces demonstrates that their wettability is a property of the treated surface.
It should not be inferred solely from the appearance or molecular formula of the liquid precursor. ACS Publications
Vinyltriethoxysilane can also undergo plasma-mediated deposition or grafting processes on polyethylene.
The treatment environment introduces reaction pathways that differ from ordinary solution silanization of a hydroxylated mineral.
This distinction explains why successful attachment to an activated polymer surface does not establish equivalent behavior on an untreated polymer.
Network development
Vinyltriethoxysilane possesses three potentially hydrolyzable groups, but its condensed products need not form one uniform three-dimensional structure.
The reaction medium can favor molecular clusters, oligomers, or more extensively connected species.
Experimental observations of condensation without macroscopic gelation demonstrate the importance of distinguishing chemical conversion from network formation.
Physical form and stability
Vinyltriethoxysilane is a mobile, colorless liquid that is sensitive to moisture.
Its stored composition can change when water enters the container because hydrolysis initiates the formation of different silicon-containing species.
Keeping the material dry preserves its identity as the monomeric starting compound.
Vinyltriethoxysilane is flammable, and its vapor can form ignitable mixtures with air.
Its flash point is sufficiently low that ordinary warm processing conditions require deliberate ignition control.
Thermal decomposition or combustion can generate carbon oxides and silicon-containing residues.
PROPERTIES
Chemical class: Vinyl-functional organoalkoxysilane
Physical form: Monomeric liquid
Appearance: Clear and colorless
Molecular formula: C8H18O3Si
Structural formula: CH2=CHSi(OC2H5)3
Molecular weight: 190.32 g/mol
Organic reactive functionality: One vinyl group
Hydrolyzable functionality: Three ethoxy groups per molecule
Hydrolysis by-product: Ethanol
Condensation behavior: Forms siloxane-containing species after hydrolysis
Moisture sensitivity: Reacts with water and atmospheric moisture
pH: Not applicable to the neat liquid; prepared hydrolysates have formulation-dependent pH 808276
Boiling point: Reported values approximately 156–161 °C at atmospheric pressure
Flash point: Approximately 34 °C
Vapor pressure: Approximately 3 hPa at 20 °C
Flammability: Flammable liquid and vapor
Storage stability: Maintain dry, tightly closed conditions; no universal shelf life assigned to an unspecified grade 808276
FIRST AID
Inhalation:
Move the affected person to fresh air and keep them at rest.
Obtain immediate medical advice for breathing difficulty or significant exposure.
If breathing stops, trained personnel should provide assisted ventilation.
Skin contact:
Remove contaminated clothing and wash thoroughly with soap and water.
Seek medical advice if symptoms persist or exposure is extensive.
Eye contact:
Rinse immediately with water for at least 15 minutes, lifting the eyelids.
Remove contact lenses if easily possible.
Obtain prompt medical assessment.
Ingestion:
Do not induce vomiting.
Obtain immediate medical advice and give nothing by mouth to an unconscious person.
Note to physicians:
Treat symptomatically and provide supportive care.
HANDLING AND STORAGE
Handling:
Vinyltriethoxysilane should be transferred with measures that prevent splashing and vapor accumulation.
Wear chemical-resistant gloves, protective clothing, and eye protection selected for the task.
Ventilation:
Provide ventilation appropriate to flammable vapor exposure.
Use suitable explosion-protected equipment where an ignitable atmosphere may develop.
Storage:
Keep tightly closed in a cool, dry, ventilated area designated for flammable liquids.
Protect against moisture and separate from strong oxidizers and strong acids.
Spill and leak procedures:
Remove ignition sources and prevent entry into drains.
Collect with compatible inert absorbent and non-sparking tools.
Send contaminated material for approved chemical-waste disposal.
Handling precautions:
Control static discharge during transfer and avoid heat, sparks, and flames.
Empty containers retain hazardous residues.
Wash after handling and remove contaminated clothing promptly.
