How to design high elasticity of rubber products

Natural rubber is a sap product extracted from rubber trees in tropical countries. Synthetic rubber is artificially synthesized from chemical raw materials. Both are polymers and both have good elasticity. This is because the rubber molecule contains 5 carbon atoms and 8 hydrogen atoms, which are connected to each other in long chains. And because the molecules are moving at a high speed, the molecules in the motion are always squeezing each other, so the polymer chains forming the rubber cannot be in a straight line, but must be in a curled shape, and many molecules will be entangled with each other, like a chain. Irregular balls of wool. If you pull it hard, this curly molecular chain can be stretched, and when the pulling force is removed, it will shrink back to its original shape, so the rubber has elasticity.

Factors that improve rubber (back)elasticity:

1. The elastic order of raw rubber is as follows: NR—EPDM—SBR—NBR—CR—IIR—ACM.

2. Increase the rubber content of the rubber (or use high-resilience rubber together), and the elasticity will reach the maximum with the increase of the cross-linking density. Polysulfide bonds have better flexibility. Peroxides can also sometimes achieve better elasticity.

3. For NR, the vulcanized rubber with semi-effective vulcanization system has the best elasticity. Followed by ordinary, effective vulcanization system.

4. The large particle size of carbon black is relatively good, FEF

5. Use an appropriate amount of similar and compatible plasticizers to obtain better resilience. Non-vulcanized resins generally affect rubber elasticity.

6. The plastication of rubber is reasonable, the mixing is uniform, and the vulcanization temperature is designed according to the type of rubber (not too high) to obtain better elasticity.