Elastomers.

Elastomers.

The natural or synthetic polymers which have elastic properties is called Elastomers.
For example; rubber. 

Origin of rubber.

The word 'rubber' is derived from its early application i.e the property of weeping tree to rub out pencil writing. Many materials were impregnated with rubber to make it waterproof. However, the performance of rubber was still quite poor because it was gummy at the time and fluctuation in temperature cause change in products.

It was the year 1839, when Goodyear accidentally discovered the vulcanisation of rubber, which makes the rubber elastic and it can keep or preserve its characteristics with fluctuation in temperature.

Types.

There are two types of rubber.

1) Natural rubber: Natural rubber is produced from latex i.e the milky emulsion extracted from rubber tree or other plants, where the coagulated latex is transform into sticky, soft and plastic substance (Crude rubber) and then Vulcanised (Cured). The rubber is composed of polyisoprene molecule. Rubber serve as an adhesives. The natural rubber has the following structural formula in which there is alternate double bond on every carbon atom.

Natural rubber.

The natural rubber when treated with proton donor such as sulphuric acid etc gives cyclised rubber. Natural rubber when treated with chlorine gives chlorinated rubber.

2) Synthetic rubber: Synthetic rubber are elastomers which have properties similar to natural rubber. They are composed of material similar to natural rubber. Some synthetic rubber are polybutadiene, butyl rubber, neoprene and silicone etc.