The English used in this article may not be easy for everybody to understand. (May 2012)
Rubber is a material which can stretch and shrink. It is a polymer. It can be produced from natural sources (e.g. natural rubber) or can be synthesised on an industrial scale. Many things are made from rubber, like gloves, tires, plugs, and masks. A few things can be made only from rubber.
Sometimes the word means only natural rubber (latex rubber). Natural rubber is made from the white sap of some trees such as the Hevea brasiliensis (Euphorbiaceae). Other elastomers, called synthetic rubbers, are made by chemical processes.
Hevea brasiliensis is the tree that most rubber comes from. Other plants that have the special sap (called latex) are figs (Ficus elastica), Castilla (Panama rubber tree), euphorbias, lettuce, the common dandelion, Taraxacum kok-saghyz (Russian dandelion), Scorzonera tau-saghyz, and Guayule.
In the 1800s, most sap to make rubber came from South America. In 1876 Henry Wickham got seeds from rubber trees in Brazil, and took them to Kew Gardens, England, and sent them to Ceylon (Sri Lanka), Indonesia, Singapore and British Malaya. Later, Malaya (now Malaysia) made the most rubber. People tried to grow rubber in India, in 1873 at the Botanical Gardens, Kolkata. The first Hevea farms in India were made at Thattekadu in Kerala in 1902. The Congo Free State in Africa also grew a lot trees for rubber at the start of the 20th century, and most of the people who worked on those farms were forced labor. Liberia and Nigeria also started growing trees to make rubber.
Charles Marie de La Condamine presented samples of rubber to the Académie Royale des Sciences of France in 1736. In 1751 François Fresneau read a paper to the Académie (eventually published in 1755) which described many of the properties of rubber. This has been referred to as the first scientific paper on rubber.
Natural rubber melts in heat and freeze in the cold. In 1844 Charles Goodyear found a way to improve natural rubber, in a chemical process known as vulcanization, which made it useful in many more products including, decades later, tires.
In the 20th century synthetic (artificial) rubbers such as Neoprene began to be used. They were much used when World War II cut off supplies of natural rubber. They have continued to grow because natural rubber is becoming scarce and also because for some uses they are better than natural rubber.
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