Vinyltriethoxysilane

CAS No.: 78-08-0

Vinyltriethoxysilane (CAS No. 78-08-0) is a vinyl-functional silane coupling agent widely used to improve adhesion and crosslinking between inorganic substrates and organic polymer systems. The vinyl group can participate in free-radical polymerization or peroxide curing reactions, while the triethoxysilane moiety hydrolyzes and bonds to glass, silica, metal oxides, and mineral surfaces. It is commonly applied in rubber, plastics, wire & cable insulation, coatings, sealants, and composite materials to enhance mechanical strength, moisture resistance, and long-term durability.

Chemical Name	Vinyltriethoxysilane
CAS No.	78-08-0
EINECS No.	201-083-8
Empirical Formula	C₈H₁₈O₃Si
Molecular Weight	190.31 g/mol

Synonyms : Vinyltriethoxysilane / Triethoxyvinylsilane / Vinyl ethyl silicate / Vinyl-functional silane / VTES / Z-6300 / KH-151 / A-151

Category : Organosilicon Chemicals / Silanes / Functional Silanes / Vinyl Silane ; Vinyl Functional Silane / Silane Coupling Agent / Unsaturated Organosilane / Trialkoxy Silane / Functional Organosilicon Intermediate

Product Description

Vinyltriethoxysilane (CAS No. 78-08-0) is a vinyl-functional silane coupling agent designed to chemically bridge inorganic substrates and organic polymer matrices. The vinyl group participates in free-radical polymerization, peroxide curing, or grafting reactions with polymers such as polyethylene, EVA, EPDM, silicone rubber, and unsaturated resins, while the triethoxysilane moiety hydrolyzes and condenses with hydroxylated surfaces including glass, silica, metal oxides, and mineral fillers to form durable Si–O–Si / Si–O–M bonds.

This dual functionality improves interfacial adhesion, crosslinking efficiency, and filler reinforcement, leading to enhanced mechanical strength, moisture resistance, and long-term durability. Vinyltriethoxysilane is widely used in rubber and plastics compounding, wire & cable insulation (moisture-curing and peroxide systems), coatings, sealants, and composite materials where robust bonding and processing flexibility are required.

Specifications

Item	Specification
Appearance	Colorless to pale yellow clear liquid
Purity	≥ 97% (typical commercial grade ≥95%)
Density (25 °C)	~0.89–0.92 g/cm³
Viscosity (25 °C)	Low
Boiling Point	~165–170 °C
Flash Point	~45–50 °C
Solubility	Soluble in alcohols and most organic solvents; hydrolyzes in water
Refractive Index (25 °C)	~1.395–1.400
Hydrolyzable Ethoxy Content	~47–50 wt%
Moisture Sensitivity	Moisture-sensitive (trialkoxy silane)
Storage Stability	12 months in tightly sealed original container
Recommended Storage	Cool, dry, well-ventilated area; protect from moisture, heat, and oxidizing agents

Note: Specifications are subject to agreement and may be adjusted according to specific customer or application requirements.

Features

Vinyl-functional silane enabling participation in free-radical polymerization, peroxide curing, and grafting reactions
Triethoxysilane groups provide reliable hydrolysis and strong chemical bonding to hydroxylated inorganic surfaces
Dual functionality allows effective coupling between polymers and inorganic fillers or substrates
Good compatibility with rubber, plastics, silicone rubber, and moisture-curing systems
Well-established, industry-standard vinyl silane with broad global use

Advantages

Enhances adhesion and interfacial bonding between polymers and glass, silica, and mineral fillers
Improves crosslinking efficiency and filler reinforcement in rubber and plastic systems
Increases mechanical strength, abrasion resistance, and durability
Improves moisture resistance and long-term aging performance
Supports efficient processing with low dosage requirements
Widely proven in large-scale industrial applications, especially wire & cable

Application

Wire & Cable: moisture-curing and peroxide-crosslinked polyethylene (XLPE), insulation and jacketing compounds
Rubber Compounds: EPDM, silicone rubber, and unsaturated rubber systems
Plastics & Composites: mineral-filled thermoplastics and thermosets
Coatings & Sealants: adhesion promotion on inorganic substrates
Glass Fiber & Mineral Filler Treatment: improved dispersion and reinforcement
Silicone Rubber Systems: grafting and crosslinking aid

Chemical & Physical Properties

Item	Description
Chemical Name	Vinyltriethoxysilane
CAS No.	78-08-0
Molecular Formula	C₈H₁₈O₃Si
Molecular Weight	190.31 g/mol
Chemical Type	Vinyl-functional trialkoxy silane
Physical State	Liquid
Appearance	Colorless to pale yellow transparent liquid
Odor	Mild characteristic odor
Density (25 °C)	~0.89–0.92 g/cm³
Viscosity (25 °C)	Low
Boiling Point	~165–170 °C
Flash Point	~45–50 °C
Vapor Pressure	Moderate (compared with higher-boiling silanes)
Solubility	Soluble in alcohols and most organic solvents; reacts with water
Hydrolysis	Triethoxy groups hydrolyze in the presence of moisture
Condensation	Forms Si–O–Si / Si–O–M networks on inorganic surfaces
Stability	Stable when dry and sealed; moisture-sensitive

Usage & Dosage

Application Methods

Direct addition: rubber, plastic, and cable compounds
Surface treatment: glass fiber, silica, mineral fillers
Pre-hydrolyzed application: primers and slurry treatment where uniform coupling is required

Typical Dosage Ranges

Rubber / plastic compounding:
- 0.5–2.0 wt% based on polymer or filler content
Filler / fiber surface treatment:
- 0.5–1.5 wt% based on filler or fiber weight

Processing Notes

In peroxide-cured systems, vinyl groups participate directly in crosslinking
Moisture-curing systems rely on controlled hydrolysis and condensation
Avoid excess moisture during processing to prevent premature condensation

Safety & Compliance

Item	Information
GHS Classification	Flammable Liquid; Skin Irritation; Eye Irritation
Signal Word	Warning
Hazard Statements	H226: Flammable liquid and vapor; H315; H319
GHS Pictogram	Flame / Exclamation Mark
PPE	Chemical-resistant gloves, goggles, protective clothing; adequate ventilation
Handling Notes	Keep away from heat, sparks, and open flame; avoid moisture
Storage Conditions	Cool, dry, well-ventilated area; tightly sealed containers
Incompatibilities	Moisture/water, strong oxidizers
UN Number	UN 1993 (commonly classified as flammable liquid; check SDS)
Transport	ADR / IMDG / IATA: Flammable liquid classification may apply
Packaging	Steel or HDPE drums
Documentation	SDS available upon request (controlling document)

FAQs

Q1: What is Vinyltriethoxysilane mainly used for?
It is primarily used as a vinyl silane coupling agent for rubber, plastics, wire & cable, and composite materials to improve adhesion, crosslinking, and durability.

Q2: Why is it popular in wire & cable applications?
The vinyl group readily participates in peroxide or moisture-curing reactions, improving crosslink density and moisture resistance in polyethylene insulation systems.

Q3: What substrates does it bond to effectively?
Glass, silica, alumina, mineral fillers, and metal oxides with surface –OH groups.

Q4: How does it differ from vinyltrimethoxysilane?
Triethoxy silanes hydrolyze more slowly than trimethoxy analogs, offering better processing control and reduced premature condensation in some systems.

Q5: Is it moisture sensitive?
Yes. Like all trialkoxy silanes, it hydrolyzes in the presence of moisture and should be stored tightly sealed.

Q6: Is it flammable?
Yes. Vinyltriethoxysilane is typically classified as a flammable liquid, and appropriate storage and transport precautions are required.

Q7: Typical performance benefits?
Improved mechanical strength, better filler reinforcement, enhanced moisture resistance, and longer service life.

Packaging & Storage

Packaging: 500 g / 1 kg / 5 kg / 25 kg / 200 kg drums / 1000L IBC container (Customized packaging is available).

Storage:

Store in tightly sealed original containers
Keep in a cool, dry, and well-ventilated area
Protect from moisture, humidity, and direct sunlight
Avoid contact with water, acids, and oxidizing agents
Recommended storage temperature: ambient conditions

Shelf Life: 12 months from date of manufacture when stored under recommended conditions.

Disclaimer

“The information provided herein is based on general industry experience and is intended for reference purposes only. Actual performance and optimal usage conditions may vary depending on formulation, processing methods, substrate characteristics, and end-use requirements. Users are responsible for conducting their own tests and evaluations to determine suitability for their specific applications. No warranty, express or implied, is made regarding the completeness, accuracy, or applicability of this information.”

Grace Gao / Sales Manager
Email : Inquiry@SiliconChemicals.com
Tel : +86-133-3518-4513
WhatsApp : +8613335184513

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Product Overview

Vinyltriethoxysilane

CAS No.: 78-08-0