Application of Silane Coupling Agent in Composite Materials

Composite materials refer to materials processed from specific materials such as matrix resins, reinforcing materials (fillers, glass fibers), functional auxiliaries (coupling agents, release agents, tougheners, etc.), mainly unsaturated polyesters. Composite materials, phenolic molding compounds, epoxy molding compounds, epoxy potting compounds, epoxy casting materials, epoxy glass fiber cloth and so on. Its characteristics are: high strength, high electrical properties, good moldability.

The silane coupling agent contains a siloxane group that can react with the inorganic filler and an epoxy group, an amino group, a vinyl group, and the like that react with the organic resin. As a commonly used additive in composite materials, its role is to improve the wettability of the matrix resin to the filler and the glass fiber, so that the matrix resin is connected with the filler or the glass fiber through the chemical bond, thereby improving the bending strength and impact strength of the composite material. Water resistance, electrical properties, etc.

Toughened silane coupling agents refer to flexible long chains containing a certain molecular weight between the siloxane groups and the organic reactive groups. Due to the presence of the flexible long chain, the chemical bonding density of the surface layer of the filler in the composite material is appropriately reduced. When the composite material is subjected to external impact, the flexible chain wrapped on the surface of the filler can absorb impact energy well. This improves the impact strength of the composite and reduces stress cracking. At the same time, since the long-chain silane coupling agent is mostly dispersed in the surface layer of the filler, the content of the resin layer is small, and the appropriate amount of the silane coupling agent has little effect on the heat distortion temperature and the glass transition temperature of the composite material.