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Rubber has several meanings including:

Natural rubber, a latex material, originally from the Para rubber tree
Latex, the sap from various plants, including the rubber tree, that is a major component in the production of natural rubber.
Latex (polymer) - A stable dispersion (emulsion) of polymer microparticles in an aqueous medium.
Elastomer, frequently used interchangeably with 'rubber' to describe elastic polymeric (rubbery) materials, particularly man-made rubbers
Synthetic rubber, general term for many types of man-made rubbers
Rubber, two 100-point games in contract bridge
In baseball, the rubber is the thin white slab on the pitcher's mound from which the pitcher throws, or at times, the pitcher's mound in general
In some sports, including tennis and cricket, an individual game in a series of matches
Rubber, a name adopted by the band Harem Scarem from 1999 - 2001
Rubber (film), a 1936 Dutch film
Rubber (Gilby Clarke album), a solo album by former Guns N' Roses guitarist Gilby Clarke
In British English, an eraser used to remove pencil markings from paper
In British English, a slang term for galoshes (rubber boots)
In American English, Slang term for condoms
Rubber (electrical part)


Natural rubber is an elastomer (an elastic hydrocarbon polymer) that was originally derived from a milky colloidal suspension, or latex, found in the sap of some plants. The purified form of natural rubber is the chemical polyisoprene, which can also be produced synthetically. Natural rubber is used extensively in many applications and products, as is synthetic rubber

Varieties
The commercial source of natural rubber latex is the Para rubber tree (Hevea brasiliensis), a member of the spurge family, Euphorbiaceae. This is largely because it responds to wounding by producing more latex.

Other plants containing latex include Gutta-Percha (Palaquium gutta),[1] rubber fig (Ficus elastica), Panama rubber tree (Castilla elastica), spurges (Euphorbia spp.), lettuce, common dandelion (Taraxacum officinale), Russian dandelion (Taraxacum kok-saghyz), Scorzonera (tau-saghyz), and Guayule (Parthenium argentatum). Although these have not been major sources of rubber, Germany attempted to use some of these during World War II when it was cut off from rubber supplies[citation needed]. These attempts were later supplanted by the development of synthetic rubbers. To distinguish the tree-obtained version of natural rubber from the synthetic version, the term gum rubber is sometimes used.

Discovery of commercial potential
The para rubber tree initially grew in South America. Charles Marie de La Condamine is credited with introducing samples of rubber to the Académie Royale des Sciences of France in 1736. In 1751, he presented a paper by François Fresneau 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.

When samples of rubber first arrived in England, it was observed by Joseph Priestley, in 1770, that a piece of the material was extremely good for obliterating pencil marks on paper, hence the name rubber.

South America remained the main source of the limited amounts of latex rubber that were used during much of the 19th century. However in 1876, Henry Wickham gathered thousands of para rubber tree seeds from Brazil, and these were germinated in Kew Gardens, England. The seedlings were then sent to Ceylon (Sri Lanka), Indonesia, Singapore and British Malaya. Malaya (now Malaysia) was later to become the biggest producer of rubber. About 100 years ago, the Congo Free State in Africa was also a significant source of natural rubber latex, mostly gathered by forced labour. Liberia and Nigeria also started production of rubber.

In India, commercial cultivation of natural rubber was introduced by the British Planters, although the experimental efforts to grow rubber on a commercial scale in India were initiated as early as 1873 at the Botanical Gardens, Calcutta. The first commercial Hevea plantations in India were established at Thattekadu in Kerala in 1902. In the 19th and early 20th century, it was often called "India rubber."

[edit] Properties

Rubber latexRubber exhibits unique physical and chemical properties. Rubber's stress-strain behavior exhibits the Mullins effect, the Payne effect, and is often modeled as hyperelastic. Rubber strain crystallizes.

Owing to the presence of a double bond in each repeat unit, natural rubber is sensitive to ozone cracking.

[edit] Solvents
There are two main solvents for rubber: turpentine and naphtha (petroleum). The former has been in use since 1763 when François Fresnau made the discovery. Giovanni Fabronni is credited with the discovery of naphtha as a rubber solvent in 1779. Because rubber does not dissolve easily, the material is finely divided by shredding prior to its immersion.

An ammonia solution can be used to prevent the coagulation of raw latex whi

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