The most important raw material in an eraser is rubber. The rubber may be natural or synthetic. Natural rubber is obtained from latex produced by the rubber tree (Hevea brasilienesis). Synthetic rubber exists in a wide variety of forms. The most common synthetic rubber is derived from the chemicals styrene and butadiene. Styrene is a liquid derived from ethylbenzene. Ethylbenzene is usually made from ethylene and benzene, both of which are derived from petroleum. Butadiene is a gas, derived either directly from petroleum or from substances known as butanes and butenes, which are derived from petroleum.
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