NATURAL RUBBER:

The organic polymers possessing elasticity to the extent of nearly 200 to 300 percent are known as elastomers or rubber.

TYPES OF RUBBER:

There are two types of rubber

1.Natural rubber: Natural rubber is obtained from latex, a milky emulsion, collected from rubber tree. It is nothing but the milky white watery emulsion of isoprene.

Structure of natural rubber: Natural rubber is cis-polyisoprene which can be represented as,

Due to cis form, the polymer develops coiled structure, and hence possesses elasticity. In cis-form, the distance between groups lying in the same plane is 8.1A0 and methyl groups are oriented outward.

Coiled structure of natural rubber :

Drawbacks of natural rubber

1- Get damaged under the action of strong acid, ozone, oils, greases and fats.

2- Not recommended for use in alcohols, esters, or among the aromatic solution.

3- Low temperature properties.

4- Higher raw material prices.

5- Does not apply to hot water being.

6- Cannot be used in power transmission systems.