Rubber, together with plastics and fibers, is known as the three major synthetic materials, and is the only polymer material with high stretchability and excellent elasticity. The biggest characteristic of rubber is firstly that the elastic modulus is very small, and the elongation is very high. The second is that it has quite good air permeability and resistance to various chemical media and electrical insulation. Some special synthetic rubbers have good oil resistance and temperature resistance, and can resist the swelling of fatty oil, lubricating oil, hydraulic oil, fuel oil and solvent oil; the cold resistance can be as low as -60℃ to -80℃, and the heat resistance can be Up to +180°C to +350°C. Rubber is also resistant to various flexural and bending deformations because of low hysteresis loss. The third characteristic of rubber is that it can be used, blended and compounded with a variety of materials, thereby being modified to obtain good comprehensive properties.