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Rubber is an elastic hydrocarbon polymer which occurs as a milky emulsion (known as latex) in the sap of a number of plants but can also be produced synthetically. The major commercial source of the latex used to create rubber is the Para rubber tree, Hevea brasiliensis ( Euphorbiaceae). This is largely because it responds to wounding by producing more latex. Other plants containing latex include figs, euphorbias and the common dandelion. These have not been a major source of rubber, though when Germany was cut off from supplies of rubber during World War II, attempts were made to use such sources, before being supplanted by the development of synthetic rubber.
It is believed to have been named by Joseph Priestley, who discovered in 1770 that dried latex rubbed out pencil marks.
In its native Central America and South AmericaSouth America is a continent crossed by the equator, with most of its area in the Southern Hemisphere. South America is situated between the Pacific Ocean and the Atlantic Ocean. It became attached to North America only recently, geologically speaking, wi, rubber has been collected for a long time. The MesoamericaMesoamerica is the region extending from central Mexico south through the northwestern border of Costa Rica that gave rise to a group of stratified, culturally related agrarian civilizations spanning an approximately 3,000-year period before the Europeann civilizations used rubber mostly from Castilla elastica . The Ancient Mesoamericans had a ball game using rubber balls (see: Mesoamerican ballgameGreat Ball Court at Chichen Itz The Ball Court. A Ball Court Goal, Chichen. Ball court marker From the Maya site of Chinkultic Dated to 591 The Mesoamerican ballgame was a sport with ritual associations played for over 3000 years by the peoples of Mesoame), and a few Pre-ColumbianThe term Pre-Columbian is used to refer to the cultures of the New World in the era before significant European influence. While technically referring to the era before Christopher Columbus, in practice the term usually includes indigenous cultures as the rubber balls have been found (always in sites that were flooded under fresh water), the earliest dating to about 1600 BC. According to Bernal Díaz del CastilloBernal Diaz del Castillo ( 1492 or 1493 1581) was a conquistador, who wrote an eyewitness account of the conquest of Mexico under Hernan Cortes. Born in Spain, he came from a family of little wealth and he himself had received only a minimal education., the SpanishThe Kingdom of Spain is a country located in the southwest of Europe. It shares the Iberian Peninsula with Portugal, Gibraltar and Andorra. To the northeast, along the Pyrenees mountain range, it borders France and the tiny principality of Andorra. It inc ConquistadorConquistador (meaning "Conqueror" in the Spanish language) is the term used to refer to the soldiers, explorers, and adventurers who brought much of the Americas under Spanish rule between the 15th and 17th centuries. Columbus's discovery of the New Worldes were so astounded by the vigorous bouncing of the rubber balls of the Aztecs that they wondered if the balls were enchanted by evil spirits. The Maya also made a type of temporary rubber shoe by dipping their feet into a latex mixture. Rubber was used in various other contexts, such as strips to hold stone and metal tools to wooden handles, and padding for the tool handles. While the ancient Mesoamericans did not have vulcanization, they developed organic methods of processing the rubber with similar results, mixing the raw latex with various saps and juices of other vines, particularly Ipomoea alba , a species of Morning glory.
In Brazil the natives understood the use of rubber to make water-resistant cloth. A story says that the first European to return to Portugal from Brazil with samples of such water-repellent rubberized cloth so shocked people that he was brought to court on the charge of witchcraft.
When samples of rubber first arrived in England, it was observed that a piece of the material was extremely good for rubbing out pencil marks on paper. This was the origin of the material's English name of 'rubber'. Blocks of the material are still used for this purpose, and known as 'rubbers' in England, causing occasional amusement to Americans, to whom a 'rubber' is a condom (usually made from latex). (Americans call the rubber block an 'eraser'.)
The para rubber tree initially grew only in South America, but after repeated efforts it was successfully cultivated in Southeast Asia, where it is widely grown today.
Over half of the rubber used today is synthetic, but several million tonnes of natural rubber are still produced annually.
Hypoallergenic rubber can be made from Guayule.
Early experiments in the development of synthetic rubber led to the invention of Silly Putty.
Natural rubber is often vulcanized, a process by which the rubber is heated and sulfur is added to improve resilience and elasticity. The process of vulcanization greatly improved the durability and utility of rubber from the 1830s on. The successful development of vulcanisation is most closely associated with Charles Goodyear.
Rubber as a clothing material is fetishized by some people, perhaps on the basis that the garment forms a "second skin" that acts as a surrogate for the wearer's own skin. This is known as rubber fetishism.
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