The curly long-chain molecular structure of Dongguan rubber shock-absorbing parts and the weak secondary forces existing between the molecules make the rubber material exhibit unique viscoelastic properties, and therefore has good shock absorption, sound insulation, and cushioning properties. Rubber parts are widely used for vibration isolation and shock absorption because of their characteristics of hysteresis, damping and reversible large deformation [1].
The hysteresis and internal friction characteristics of rubber shock absorbers in Dongguan are usually expressed as loss factors. The greater the loss factor, the more significant the damping and heat generation of rubber, and the more significant the shock absorption effect. The size of the rubber material loss factor is not only related to the structure of the rubber itself, but also related to temperature and frequency. At room temperature, natural rubber (NR) and butadiene butadiene rubber (BR) have small loss factors, styrene butadiene rubber (SBR), neoprene (CR), ethylene propylene rubber (EPR), urethane rubber (PU) and silicone rubber. The loss factor is centered, and butyl rubber (HR) and nitrile rubber (NBR) have the largest loss factor.
Rubber materials used for shock absorption purposes are generally divided into 5 types, namely NR, SBR, BR for ordinary rubber materials; NBR for oil vulcanizates; CR for weather resistant vulcanizates; IIR for high damping vulcanizates; EPR for Heat-resistant vulcanizates. Although NR has a small loss factor, its overall performance is the best. Dongguan rubber shock absorbers have excellent elasticity, good fatigue resistance, low heat generation, small creep, good adhesion to metal parts, cold resistance, and electrical insulation. And processing performance is also good, so NR is widely used for shock absorption purposes, requires low temperature or weather resistance, can be used with BR or CR modified or blended. Nishiue et al. used NR, BR, and a shock absorber made of a metal salt containing an -OH group organic acid having a carbon number of more than 4 to have better durability performance, and was compressed at 70°C×22h and 40°C×148h. The permanent deformations were 17.0% and 11.7%, respectively.