The curled long chain molecular structure of rubber and the weak secondary force between the molecules make the rubber material exhibit unique viscoelastic properties, so it has good shock absorption, sound insulation and cushioning properties. Rubber components are widely used to isolate vibration and absorb shock because of their hysteresis, damping and reversible large deformation characteristics.

The hysteresis and internal friction characteristics of rubber are usually expressed by loss factor. The greater the loss factor is, the more significant the damping and heating of rubber are, and the more obvious the shock absorption effect is.

The loss factor of rubber material is not only related to the structure of rubber itself, but also to temperature and frequency. At room temperature, the loss factors of natural rubber (NR) and cis-butadiene rubber (BR) are small, while those of styrene-butadiene rubber (SBR), chloroprene rubber (CR), ethylene-propylene rubber (EPR), polyurethane rubber (PU) and silicone rubber are middle, and those of butyl rubber (HR) and nitrile rubber (NBR) are the largest.

There are five kinds of rubber materials for shock absorption, namely NR, SBR and BR, which are ordinary rubber materials; NBR is used for oil-resistant vulcanizates; CR is used for weather-resistant vulcanizates; IIR is used for high-damping vulcanizates; EPR is used for heat-resistant vulcanizates. Although the loss factor of NR is small, it has the best comprehensive performance, excellent elasticity, good fatigue resistance, low heat generation, low creep, good adhesion to metal parts, good cold resistance, electrical insulation and processing performance. Therefore, NR is widely used as shock absorber. When low temperature or weather resistance is required, it can be modified by blending with BR or CR. Nishiue and other shock absorbers made of NR, BR and metal salts containing organic acids with carbon atom number greater than 4 have good durability. The compression permanent deformations of the shock absorbers at 70 22h and 40 148h are 17.0% and 11.7% respectively.