Silane coupling agents are a class of organosilicon compounds with two different chemical groups in the molecule. Their classical products can be expressed by the general formula YSiX3. In the formula, Y is a non-hydrolyzable group and X is a hydrolyzable group. Because of this special structure, silane coupling agents act on the interface of inorganic materials (such as glass, metal or minerals) and organic materials (such as organic polymers, coatings or adhesives), combining or coupling two distinct materials. It can enhance the affinity between organic and inorganic compounds, and enhance the physical and chemical properties of composites, such as strength, toughness, electrical properties, water resistance and corrosion resistance.

What is silane coupling agent?

Silane coupling agents are a class of organosilicon compounds with two different chemical groups in the molecule. Their classical products can be expressed by the general formula YSiX3. In the formula, Y is a non-hydrolyzable group and X is a hydrolyzable group. Because of this special structure, silane coupling agents act on the interface of inorganic materials (such as glass, metal or minerals) and organic materials (such as organic polymers, coatings or adhesives), combining or coupling two distinct materials. It can enhance the affinity between organic and inorganic compounds, and enhance the physical and chemical properties of composites, such as strength, toughness, electrical properties, water resistance and corrosion resistance.

When glass fibers or minerals are used to reinforce organic polymers, the interface or interface between polymers and inorganic materials involves complex interactions between many physical and chemical factors. These factors are related to adhesion, physical strength, expansion coefficient, concentration gradient and product performance retention. An important destructive force affecting adhesion is water migration to inorganically enhanced hydrophilic surfaces. Water erodes the interface and destroys the bonding.
"Real" coupling agents can form water-resistant bonds at the interface between inorganic and organic materials. Silane coupling agent has unique chemical and physical properties, which not only enhances the bond strength, but also prevents bond disintegration at the interface during aging and use of composite materials.  Coupling agents give stable bonding between two dissimilar surfaces that are difficult to bond.
The flexural strength of composites can be increased by more than 40% by choosing appropriate silane. Silane coupling agents also enhance the bonding strength between coatings and adhesives, as well as the resistance to humidity and other malignant environmental conditions.
Other advantages that silane coupling agents can offer include:
1. Better wetting inorganic materials
2. Lower viscosity when compounded
3. Smoother Composite Surface
4. Reduce Inhibitory Effect of Inorganic Materials on Thermosetting Composite Catalysts
5. Clear and Transparent Reinforced Plastics


Coatings using silane coupling agents have the following advantages:
1. Corrosion resistance
2. Improving adhesion
3. Improving rheological properties
4. Improving the Dispersibility of Dyes and Fillers
5. Anti-ultraviolet radiation
6. Waterproof and Chemical Resistance
Synthetic synthetic rubber and resin coatings usually encounter adhesion problems on hydrophilic silicate and metallic surfaces. Especially in high tide, water or salinity, the protective effect of coatings depends on adhesion promoters on the surface of substrates. Whether as a coating additive or primer, silane coupling agent can improve the performance of coatings.