Natural rubber is produced from latex - milky emulsion drawn from the rubber tree (Hevea brasiliensis) or some other plants. When coagulated latex transforms into soft, plastic and sticky substance (crude rubber), which is then vulcanized (cured). Natural rubber is composed of polyisoprene molecules.
Synthetic rubbers are Elastomers, elastic properties of which are similar to those of the natural rubber. Synthetic rubber may have chemical composition similar to the natural rubber (synthetic polyisoprene). Other kinds of synthetic rubbers are: polybutadiene, poly(styrene-butadiene-styrene), polychloroprene (Neoprene), polyisobutylene (Butyl rubber), silicone.