What is a rubber

It is a kind of reversible deformation elastomeric polymer material. 

Under room temperature,it has the characterrictic of elastic. Under a small external force ,it can produce large deformation,after you remove the external force ,it can restore the status in the previous condition. Rubber belong to a completely amorphous polymer, its glass transition temperature (Tg) is low .And molecular weight tend to be large, more than hundreds of thousands. 

The word rubber comes from the Indian language of rubber cau-uchu, meaning "weeping tree." When natural rubber is Hevea tapping by the outflow of latex by coagulation, drying and produced. In 1770, British chemist J. Priestley found that rubber can be used to wipe away the pencil writing, then the material for this purpose is called a rubber, this word ha been used until now. Molecular chains may be crosslinked rubber, rubber crosslinked deformed by external force,it has the ability to recover quickly, and has good physical and mechanical properties and chemical stability.

 Rubber is the rubber industry's basic raw material, which was widely used in the manufacture of tires, hoses, plastic, cables and other various rubber products.