Coupling agent is a class of substances with two functional groups of different properties. The unique feature of its molecular structure is that the molecule contains two groups with different chemical properties, one is an inorganic-friendly group, which is easy to interact with inorganic substances. The surface reacts chemically; the other is an organophilic group, which can chemically react with synthetic resins or other polymers or generate hydrogen bonds to dissolve in them. Therefore, the coupling agent is called "molecular bridge", which is used to improve the interface between inorganic substances and organic substances, thereby greatly improving the properties of composite materials, such as physical properties, electrical properties, thermal properties, optical properties, etc. Coupling agents used in the rubber industry can improve the wear resistance and aging resistance of tires, rubber sheets, rubber hoses, rubber shoes and other products, and can reduce the amount of NR, thereby reducing costs. The role of the coupling agent in the composite material is that it can not only react with some groups on the surface of the reinforcing material, but also react with the matrix resin to form an interface layer between the reinforcing material and the resin matrix, and the interface layer can transmit stress, Therefore, the bonding strength between the reinforcing material and the resin is enhanced, the performance of the composite material is improved, and the penetration of other media into the interface can be prevented, the interface state can be improved, and the aging resistance, stress resistance and electrical insulation properties of the product can be improved.