Monochloromethyltriethoxysilane (HC-CE8323) : "Universal Adhesive" in Industry

Chloromethyltriethoxysilane is an important organosilicon compound with unique molecular structure and properties, and is widely used in many fields.

Chemical name: Chloromethyltriethoxysilane

English name: Chloromethyltriethoxysilane

CAS No.: 15267-95-5

Molecular formula: C7H17ClO3Si

Molecular weight: 212.75

Ⅰ. Product Introduction

In the molecular structure of chloromethyltriethoxysilane, the silicon atom is the core, one covalent bond is connected to the chloromethyl group ( -CH₂Cl ), and the remaining three covalent bonds are connected to the ethoxy group ( -OCH₂CH₃ ), thus forming a typical tetrahedral configuration.

Chloromethyl part: The carbon atom is connected to the silicon atom, and the chlorine atom is connected to the carbon atom through a single bond. Due to the large electronegativity of the chlorine atom, the chloromethyl group exhibits a certain polarity. The oxygen atom in the ethoxy group, with its lone pair of electrons, can form a stable covalent bond with the silicon atom. At the same time, the overall spatial configuration of the ethoxy group also affects the physical and chemical properties of chloromethyltriethoxysilane.

This unique structure makes chloromethyltriethoxysilane have important application value in organosilicon chemistry and material science, especially in the fields of surface modification, adhesives, silicone resin synthesis, etc., showing unique properties, giving chloromethyltriethoxysilane performance characteristics that are different from other silane compounds.

Physical properties:

Chemical properties and solubility analysis:

Chemical properties

Hydrolysis reaction: Under the action of water, the ethoxy group of chloromethyltriethoxysilane is easily hydrolyzed to generate silanol and release ethanol. Under limited water or acid-base catalysis conditions, silanol will further condense to form siloxane polymers. This property is crucial in applications in the fields of coatings and adhesives. By controlling the degree of hydrolysis and condensation reactions, materials with different structures and properties can be prepared.

Nucleophilic substitution reaction: The chlorine atom in the chloromethyl group has a high electrophilicity due to the polar bond (C–Cl) formed with carbon, and is easily attacked by nucleophilic reagents (such as amines, alcohols, thiols, etc.), resulting in nucleophilic substitution reaction (mainly SN2 mechanism). This property can be used to introduce specific functional groups such as amine (–NH₂), hydroxyl (–OH) or thiol (–SH) into silane molecules, thereby expanding its application in surface modification, functional silicone synthesis, etc.

Solubility

Chloromethyltriethoxysilane is soluble in common organic solvents such as ethanol, toluene, tetrahydrofuran (THF), dichloromethane, etc., and exhibits good organic phase affinity. This property makes it suitable for the synthesis and solution processing of silicone materials. However, due to the hydrophobicity of the ethoxy group (–OCH₂CH₃) and chloromethyl group (–CH₂Cl) in its molecular structure, the solubility of this compound in water is low. However, in the presence of acid or base catalysts, it can be slowly hydrolyzed in the aqueous phase and may form a stable emulsion or dispersion system, which is particularly important in coating and adhesive applications.

Ⅱ. Security

When studying the performance and application of chloromethyltriethoxysilane, its safety cannot be ignored.

Chloromethyltriethoxysilane is a flammable liquid (GHS Category 3). During storage and use, it should be kept away from fire, heat sources and oxidants. It is strictly forbidden to use open flames, smoke or perform high-temperature operations in the operating area. Use explosion-proof electrical equipment to prevent static electricity accumulation and ground discharge when necessary. Avoid long-term exposure to air to prevent hydrolysis and polymerization reactions. Avoid hygroscopic decomposition and store in a cool, dry special chemical storage area.

Chloromethyltriethoxysilane is highly irritating to the skin, eyes and mucous membranes, and may cause skin redness, itching, chemical burns, and even corneal damage. It should be immediately rinsed with plenty of running water for at least 15 minutes. If irritation or burns occur, seek medical attention as soon as possible.

The vapor of chloromethyltriethoxysilane may cause strong irritation to the respiratory tract. Long-term or high-concentration exposure may cause breathing difficulties, dizziness, coughing, and even pulmonary edema. A standard gas mask should be worn during operation. In the event of an inhalation accident, the patient should be immediately moved to fresh air and the airway should be kept open. If breathing is difficult, oxygen should be given, artificial respiration should be performed if necessary, and medical attention should be sought immediately.

Ⅲ. Application of Chloromethyltriethoxysilane

Organic synthesis intermediates:

Chloromethyltriethoxysilane is widely used in organic synthesis due to its high reactivity of chloromethyl and ethoxy groups. Through nucleophilic substitution reaction, a variety of functionalized organosilicon compounds can be synthesized, such as for the preparation of α- carbon functional group silane coupling agent ND -42.

Coatings and Adhesives:

In coatings and adhesives, chloromethyltriethoxysilane can be used as a crosslinking agent. Its hydrolysis and condensation reaction can form a three-dimensional network structure, thereby improving the hardness, wear resistance and chemical corrosion resistance of the coating. In adhesives, it enhances the bond, especially to difficult-to-bond materials such as polyolefins.

Composite materials: As a coupling agent, chloromethyltriethoxysilane can enhance the bonding strength between inorganic fillers and organic matrices. For example, in glass fiber reinforced plastics, the glass fibers treated with it can significantly improve the tensile strength, flexural strength, water resistance and heat resistance of the composite materials.

Surface treatment: Chloromethyltriethoxysilane can form an organic silicone protective layer on the surface of the material. In terms of metal treatment, it can react with the hydroxyl groups on the metal surface to improve the adhesion between the metal and the coating. It is often used in the pre-treatment of automotive parts for painting to enhance corrosion resistance and durability and extend service life.

IV. Conclusion

Chloromethyltriethoxysilane is an important organosilicon compound with reactive chloromethyl groups and hydrolyzable ethoxysilane groups. It has various synthesis methods and unique physical and chemical properties. It has broad application prospects in surface modification, organic synthesis, drug synthesis, material science and other fields. However, due to its certain irritation and corrosiveness, safety precautions should be taken when using it. With the continuous development of science and technology, the application field of monochloromethyltriethoxysilane will be more extensive.

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