The Development of Silane Coupling Agents is Promising

Coupling agent is a kind of organosilicon compound with special structure. In its molecule, there are both reactive groups that can be combined with inorganic materials (such as glass, cement, metal, etc.) and reactive groups that can be combined with organic materials (such as synthetic resins, etc.). Commonly used theories are chemical bond theory, surface infiltration theory, deformation layer theory, constraint layer theory, etc. Silane coupling agent is used as a surface modifier, which can improve its dispersibility and adhesion when it is used to fill plastics with inorganic fillers.

1. The performance of silane coupling agents

Silane coupling agent was developed early as a glass fiber treatment agent for glass fiber reinforced plastics. Since silane coupling agents improve the adhesion between the glass fiber and the resin, the mechanical properties of the reinforced plastic are significantly improved. With the rapid development of composite materials, the development speed of silane coupling agent is also very fast in terms of variety or output. In recent years, the use of silane coupling agents to introduce specific functional groups into certain materials can improve the surface properties of materials, and obtain anti-static, anti-mildew, anti-odor, anti-coagulation and physiological inertness, etc., which has become a new application of silane coupling agents beginning.

Due to the development of many important application fields, silane coupling agents have become an important branch of silicones. This characteristic of silane coupling agent has been used in glass fiber reinforced plastics (glass fiber reinforced plastic) as a surface treatment agent for glass fiber, which greatly improves the mechanical properties, electrical properties and anti-aging properties of glass fiber reinforced plastic. importance has long been recognized.

2. Three aspects of the application of silane coupling agents

(1) Surface treatment for glass fiber

It can improve the bonding properties of glass fiber and resin, and greatly improve the strength, electrical, water resistance, weather resistance and other properties of glass fiber reinforced composite materials. Even in wet state, it can improve the mechanical properties of composite materials. The effect is also very significant. At present, the use of silane coupling agents in glass fibers is quite common. The silane coupling agents used in this aspect account for about 50% of the total consumption. Among them, the most used varieties are vinyl silane, amino Silane, methacryloxysilane, etc.

(2) Used for filling plastics with inorganic fillers

The filler can be surface-treated in advance or directly added to the resin. Silane coupling agents can improve the dispersion and adhesion of fillers in resins, improve process performance and improve the mechanical, electrical and weather resistance properties of filled plastics (including rubber).

(3) Used as a tackifier for sealants, adhesives and coatings

Can improve their bonding strength, water resistance, weather resistance and other properties. Silane coupling agents can often solve the problem that some materials cannot be bonded for a long time.

The principle of silane coupling agent as a tackifier is that it has two groups; one group can be combined with the skeleton material to be bonded; and the other group can be combined with polymer materials or adhesives. Thus, a higher chemical bond is formed at the bonding interface, which greatly improves the bonding strength.