3-(Glycidyloxy)propyldimethylethoxysilane (Siwin-E3212) is an organosilane coupling agent featuring an epoxy functional group and a single hydrolyzable ethoxy group on a dimethylsilyl backbone. The glycidoxypropyl group provides reactivity toward epoxy resins, phenolic resins, and other polymer systems containing functional groups reactive with epoxide rings. The single ethoxy group differentiates this product from trialkoxy-type epoxy silanes, resulting in slower hydrolysis kinetics and lower cross-link density at the interface. The molecular formula is C10H22O3Si with a molecular weight of 218.37 g/mol.
As a specialty customized silane, Siwin-E3212 is selected for applications where controlled hydrolysis rate and moderate cross-link density are required. The dimethyl substitution on silicon provides enhanced hydrophobic character compared with trimethoxy or triethoxy analogs. This makes the product suitable for formulations requiring improved water resistance at the silane-polymer interface, as well as for systems sensitive to rapid gelation or premature cross-linking.
Property | Value |
CAS | 17963-04-1 |
Chemical Name | (3-GLYCIDOXYPROPYL)DIMETHYLETHOXYSILANE |
Boiling point | 100°C/3mmHg (lit.) |
Density | 0.95 g/mL at 25°C (lit.) |
Refractive index | n20/D 1.434 (lit.) |
Flash point | 87°C (189°F) |
Form | Liquid |
Specific gravity | 0.95 |
Hydrolytic sensitivity | Moisture-sensitive |
Formula | C10H22O3Si |
MW | 218.37 |
Siwin-E3212 functions as an adhesion promoter in epoxy-based adhesives, sealants, and coatings. The epoxy group on the silane co-reacts with the epoxy resin matrix during cure, while the hydrolyzed silane groups bond to inorganic substrates such as glass, metal, and mineral fillers. The single-alkoxy structure provides a more controlled bond layer thickness compared with trialkoxy silanes, which can be advantageous for thin-film adhesive applications and precision bonding operations.
The product is used for surface treatment of inorganic fillers and pigments including silica, alumina, calcium carbonate, and various mineral reinforcements. Treatment with Siwin-E3212 improves filler dispersion in epoxy and other polar polymer matrices, reduces compound viscosity, and enhances mechanical properties of filled composites. The dimethylsilyl group contributes to improved hydrophobicity at the filler surface.
In solvent-borne and high-solids coating systems, Siwin-E3212 improves adhesion to difficult substrates and enhances corrosion resistance performance on metal surfaces. The product is also used in silicone-epoxy hybrid sealant formulations where it contributes to cross-linking and substrate adhesion. Its lower hydrolysis rate makes it suitable for formulations requiring extended pot life.
For glass fiber and carbon fiber reinforcement in epoxy composite systems, the silane serves as a sizing component that improves fiber-matrix interfacial bonding. The controlled reactivity of the monoethoxy structure can be beneficial in fiber sizing formulations where uniform, thin silane layers are desired for optimal composite mechanical properties.
Siwin-E3212 is hydrolytically sensitive, meaning it undergoes gradual hydrolysis when exposed to atmospheric moisture, leading to silanol formation and eventual condensation polymerization. For this reason, the product must be handled under dry conditions with minimal exposure to ambient humidity. Container openings should be kept to a minimum, and any unused material should be properly resealed under dry nitrogen blanket when possible.
The product should be stored in a cool, dry, well-ventilated area in tightly sealed containers. Storage temperature should be maintained below 30°C. Containers should be protected from direct sunlight and sources of ignition. Under proper storage conditions in unopened containers, the product maintains its specified properties for 12 months from the date of manufacture.
Each production batch of Siwin-E3212 undergoes quality verification including gas chromatography purity analysis, refractive index measurement, and density testing to confirm conformance with specifications. The product is classified as a specialty/custom silane grade, and certificates of analysis are provided with each shipment. Custom purity specifications and packaging configurations can be arranged for enterprise customers with specific formulation requirements.
The product falls under HS code 2931900090 and is classified as a flammable liquid (Category 4) with skin and eye irritation potential. Safety Data Sheets (SDS) detailing hazard classification, handling procedures, and emergency response measures are available upon request. The product is manufactured under ISO 9001 quality management systems and is available for commercial procurement worldwide.
Standard packaging for Siwin-E3212 includes 25L and 200L steel drums with appropriate inner liners, as well as IBC containers for volume orders. Custom packaging options, nitrogen-purged containers, and custom purity grades are available for business buyers with specialized formulation requirements. As a customized silane product, Siwin-E3212 can be supplied with tailored specifications to meet specific application needs.
Unlike trialkoxy epoxy silanes such as GPTMS (3-glycidoxypropyltrimethoxysilane), this product has only one hydrolyzable ethoxy group and two methyl groups on silicon. This results in slower hydrolysis, lower cross-link density at the interface, and enhanced hydrophobic character, making it suitable for applications requiring controlled reactivity and improved water resistance.
They must be stored in tightly sealed containers in a cool, dry area with minimal exposure to atmospheric moisture. Nitrogen blanketing is recommended for partially used containers. Storage temperature should be maintained below 30°C, and containers should be protected from direct sunlight.
Siwin-E3212 is compatible with epoxy resins, phenolic resins, acrylics, polyurethanes, and silicone-epoxy hybrid systems. It is particularly useful in systems where the faster hydrolysis of trialkoxy silanes causes premature gelation or short pot life.
Typical dosage ranges from 0.5% to 3.0% by weight of the total formulation for adhesion promotion applications. For filler surface treatment, levels of 0.3% to 1.0% by weight of filler are common. Optimal loading should be determined through laboratory testing for each specific system.
Due to its hydrolytic sensitivity and single-alkoxy structure, the product has limited stability in water-based systems and is primarily recommended for solvent-borne or 100% solids formulations. For water-based applications, a trialkoxy epoxy silane with better hydrolysis stability in aqueous dispersion is generally more suitable.
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