The silane coupling agent is a type of silane that contains two groups of different chemical properties (the organic functional group and the hydrolyzable group) in the molecule at the same time. The molecular structure is generally as follows: YR-Si(OR)3 (where Y-organic functional group, SiOR-siloxy).
By using a silane coupling agent, a "molecular bridge" can be built between the interface of inorganic and organic substances, connecting the two materials with very different properties together to form a bonding layer of organic matrix-silane coupling agent-inorganic matrix, to improve the performance of composite materials and increase the bonding strength.
1. Surface treatment. It can improve the adhesion property of glass fibers and resins, and greatly enhance the strength, electrical, water resistance, weather resistance, and other properties of glass fibers reinforced composite materials. Even in the wet state, it can significantly improve the mechanical properties of composite materials. The use of silane coupling agents in glass fibers has been quite common, and the silane coupling agent used in this area accounts for about 50% of its total consumption.
2. Filled plastics. The silane coupling agent can pre-treat the surface of the filler, or it can be directly added to the resin. Its role is to improve the dispersibility and adhesion of the filler in the resin, facilitate the compatibility between the inorganic filler and the resin, enhance the process performance, and increase the mechanical, electrical, and weather resistance properties of filled plastics (including rubber).
3. It can be used as the sealant, adhesive, and coating tackifier to improve the material's bonding strength, water resistance, weather resistance, and other properties. Silane coupling agents can often be applied to solve the long-standing problem that certain materials cannot be bonded.
See also vinyl silane coupling agent.