Coupling agent is a kind of material with two different properties of functional groups, the biggest characteristic of its molecular structure is that the molecule contains two groups with different chemical properties, one is an inorganic group, easy to react with the inorganic surface; The other is an organophile group, which can react with synthetic resins or other polymers or form hydrogen bonds and dissolve in them.

Therefore, the coupling agent is called "molecular bridge", which is used to improve the interface between inorganic matter and organic matter, so as to greatly improve the properties of composite materials, such as physical properties, electrical properties, thermal properties, optical properties, etc. The coupling agent is used in the rubber industry, which can improve the wear resistance and aging resistance of tires, rubber plates, hose, rubber shoes and other products, and reduce the amount of NR, so as to reduce the cost.

Coupling agent on the role of composite materials is that it can react with certain groups on the surface of the reinforced material, and can react with matrix resin, between reinforcing materials and resin matrix in the formation of an interface layer, interface layer can pass stress, so as to enhance the bonding strength between the reinforcing materials and resin, which improves the performance of composite material, at the same time can also prevent other medium to permeate interface, The improvement of interface state is beneficial to aging resistance, stress resistance and electrical insulation properties of products.