Among general rubbers, butadiene rubber and natural rubber have the best elasticity.
In order to reduce the crystallization ability of natural rubber, the use of butadiene rubber in natural rubber can increase the elasticity of vulcanizates.
· Relationship between elasticity and vulcanization system
With the increase of crosslinking density, the vulcanizate elasticity increases, and the maximum value appears. The crosslinking density continues to increase, and the elasticity decreases. Properly increasing the degree of vulcanization is beneficial to elasticity, which means that the amount of vulcanizing agent and accelerator can Increase appropriately.
The combination of highly elastic vulcanization system. Select sulfur + sulfenamide such as S: CZ = 2: 1.5 or sulfur / guanidine SOTG = 4: 1.0

· Relationship between elasticity and filling system
The elasticity of rubber is completely provided by the rubber molecules, so increasing the rubber content is the most direct and effective way to provide high elasticity. However, in order to reduce costs, appropriate fillers must be selected.
The smaller the carbon black particle size, the greater the surface activity, the better the carbon black's reinforcing performance, and the more unfavorable the elasticity of the vulcanizate.