Siwin-TMOS is high-purity tetramethoxysilane designed for industrial material processing and specialty chemical production. It acts as a sol-gel intermediate and crosslinker for silicone rubber systems, forming a dense silica layer to enhance substrate strength and scratch resistance. Suitable for stone reinforcement, optical hard coatings, and sealing composition drying agents, it supports scalable manufacturing with stable quality.
Siwin-TMOS
Siwin
Siwin-TMOS
681-84-5
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Tetramethoxysilane (Siwin-TMOS), also known as tetramethyl orthosilicate, is a tetrafunctional alkoxysilane with the chemical formula C₄H₁₂O₄Si. Registered under CAS No. 681-84-5, this compound features a central silicon atom bonded to four methoxy groups, making it a versatile crosslinking agent and sol-gel precursor for industrial processes.
At room temperature, Siwin-TMOS is a colorless liquid with a density of 1.02 g/cm³ at 25°C. It has a boiling point of 121-122°C at 760 mmHg and a flash point of 26°C measured by Tag closed cup method. The product is supplied with a minimum purity of 98%, verified by gas chromatography. Its molecular weight is 152.22 g/mol.
The tetrafunctional structure of tetramethoxysilane enables it to form extensive silica networks through hydrolysis and condensation reactions. Each methoxy group reacts with water to generate silanol groups, which subsequently condense to form Si-O-Si bonds. This reactivity establishes TMOS as a fundamental raw material in sol-gel chemistry and silica-based material synthesis.
Product No. | Siwin-TMOS |
|---|---|
Chemical Name: | Tetramethoxysilane, Tetramethyl orthosilicate |
CAS NO. | 681-84-5 |
Formula | C₄H₁₂O₄Si |
Molecular weight: | 152 |
Boiling point at 760mmHg | 121-122℃ |
Flash point, Tag closed cup | 26℃ |
Appearance | Colorless Liquid |
Density (ρ25°C,g/cm³) | 1.02 |
Refractive Index (nD²⁵) | 1.389 |
Purity (%) | ≥98 |
Molecular Structure |  |
Siwin-TMOS can be applied neat, diluted, or as part of a formulated product to natural stones and construction materials. Upon application, it undergoes hydrolysis and condensation to form a silica-gel-like binder (SiO₂) within the pore structure of the substrate. This silica network increases substrate strength and improves resistance to weathering and abrasion. The treatment serves stone fabricators and construction material manufacturers producing exterior cladding, paving stones, and architectural surfaces.
As a key intermediate in the sol-gel process, tetramethoxysilane serves as a precursor for the synthesis of silica-based materials. Controlled hydrolysis and condensation of TMOS produce colloidal silica suspensions that can be processed into gels, films, fibers, or monolithic structures. On glass and plastic lens materials, TMOS-derived coatings provide scratch-resistant hard-coat finishes that improve surface durability and optical clarity. This application serves optical component manufacturers and specialty coating formulators.
Siwin-TMOS functions as a crosslinker in silicone rubber systems. Its four reactive methoxy groups participate in condensation cure reactions with silanol-terminated silicone polymers, forming three-dimensional network structures. The tetrafunctional nature of TMOS contributes to higher crosslink density compared with trifunctional silanes, influencing the mechanical properties and cure characteristics of the final rubber product.
In sealing compositions, tetramethoxysilane acts as a drying agent by reacting with ambient moisture. This moisture-scavenging function helps maintain the stability of moisture-sensitive formulations during storage and extends the shelf life of one-component sealant systems. As the silane reacts with residual moisture, it forms silica byproducts that integrate into the sealant matrix.
Siwin-TMOS is available in standard industrial packaging configurations, including 200L steel drums and 1000L IBC totes. Specific container sizes and fill weights are available upon request from the manufacturer.
Given its moisture-sensitive nature, tetramethoxysilane must be stored in tightly sealed containers under dry conditions. Exposure to atmospheric moisture causes gradual hydrolysis, leading to viscosity increase and eventual gelation. Storage areas should be cool, well-ventilated, and away from sources of heat and ignition. Nitrogen blanketing of storage containers is recommended for extended storage periods.
Siwin-TMOS is manufactured under controlled process conditions with systematic quality verification. Each production batch undergoes analytical testing including gas chromatography for purity assessment, density measurement, refractive index determination, and moisture content analysis. Batch records are maintained to ensure traceability from raw material intake through final product dispatch.
When stored in unopened, original containers under recommended dry conditions at room temperature, tetramethoxysilane typically maintains its specification properties for 12 months from the date of manufacture. Actual shelf life depends on storage conditions and container seal integrity.
Tetramethoxysilane undergoes hydrolysis when exposed to moisture. The methoxy groups react with water molecules to form silanol groups and methanol. Subsequent condensation reactions between silanol groups generate Si-O-Si bonds, leading to silica network formation. This reaction proceeds more rapidly under acidic or alkaline conditions and at elevated temperatures.
TMOS should be stored in tightly sealed containers in a cool, dry, well-ventilated area. Storage temperature should be maintained below 30°C whenever possible. Containers should be kept away from acids, bases, and moisture sources. Nitrogen padding of partially used containers is recommended to prevent moisture ingress.
Yes, tetramethoxysilane can be diluted with appropriate anhydrous solvents such as alcohols or hydrocarbon solvents, depending on application requirements. Dilution should be performed under moisture-free conditions to prevent premature hydrolysis. The choice of solvent and dilution ratio should be determined based on the specific application method.
Handling should occur in well-ventilated areas with appropriate personal protective equipment, including chemical-resistant gloves, safety goggles, and protective clothing. Avoid inhalation of vapors and contact with skin and eyes. TMOS is flammable and should be kept away from open flames and ignition sources. Refer to the material safety data sheet for complete safety and handling information.
