The general structural formula of the silane coupling agent is RSiX3, R represents functional groups such as mercapto, amino, and alkyl, and X is a group that can be hydrolyzed, such as a halogen atom, an alkoxy group, etc. Wherein, the alkylsilane coupling agent refers to a type of silane coupling agent whose functional group is a long-chain alkyl group.

Because its molecules contain non-polar long carbon chain alkyl groups (C8, C12, C14, etc.), the compatibility of this type of coupling agent is relatively good, and it can be used for reinforcement modification of polymers, waterproofing of concrete buildings, etc.

1. Polymer modification of alkyl silanes

Alkyl silane coupling agent, due to the effect of long-chain alkyl, can have similar and compatible physical effects with organic polymers, and can also react with the surface of inorganic fillers to bridge and couple materials with different properties. On the one hand, it promotes the dispersion of inorganic powder materials in organic polymers, and improves the effect of inorganic materials; on the other hand, bonding and coupling inorganic and organic polymer materials can increase the thickness of the interface layer between the two. Thus, effective modification of polymer materials can be achieved.

This method of improving the performance of composite materials by modifying the surface of inorganic powder materials has been widely used in tire rubber, architectural coatings, engineering plastics and other fields.

With the continuous development of science and technology, the performance requirements of polymer composite materials will also be further improved, the surface modification technology of materials will inevitably be further developed, and silane coupling agents will also flourish accordingly.

2. Waterproof treatment of alkyl silane concrete buildings

Alkyl silane coupling agent is prone to cross-linking under the action of alkaline concrete, forming a layer of hydrophobic film inside and on the surface of concrete voids, so as to achieve the purpose of resisting the penetration of harmful substances such as water and chloride ions.

In addition, the silane coupling agent can also be made into a silane paste impregnating agent, which overcomes the problem of serious loss during brushing, prolongs the contact time with the concrete substrate, and fundamentally prevents and eliminates the corrosion of the bridge concrete structure. It is an economical, practical and feasible new methods and technologies.

At present, most of the alkylsilane coupling agents used in building materials are n-octyltriethoxysilane, and the silicone paste impregnating agent prepared by it has both permeability and water resistance, and has been widely used abroad. It can be predicted that n-octyltriethoxysilane will definitely shine in the field of building materials in China in the future.

The production of most silane coupling agents is based on hydrosilylation reaction, and alkyl silane coupling agents are no exception. Alpha-olefins are monoolefins with double bonds at the end of a straight-chain alkyl group and are excellent materials for hydrosilylation. In the production process, the α-olefin is reacted with trichlorosilane in a certain proportion, and then the alkylsilane coupling agent is obtained through the alcoholysis process.

Depending on the length of the α-olefin carbon chain, n-octyltriethoxysilane, dodecyltriethoxysilane, hexadecyltriethoxysilane, etc. can be obtained.