This is achieved using superheated steam (up to 600 ☌) over an iron(III) oxide catalyst. Ethylbenzene is produced via a Friedel–Crafts reaction between benzene and ethylene originally this used aluminum chloride as a catalyst, but in modern production this has been replaced by zeolites.Īround 80% of styrene is produced by the dehydrogenation of ethylbenzene. As such, the two production processes are often highly integrated. The vast majority of styrene is produced from ethylbenzene, and almost all ethylbenzene produced worldwide is intended for styrene production. Eventually, in 1876, the Dutch chemist van 't Hoff resolved the ambiguity: the optical activity of the styrene that was obtained by distilling storax resin was due to a contaminant. However, the styrene that was obtained from cinnamic acid seemed different from the styrene that was obtained by distilling storax resin: the latter was optically active. In 1845, French chemist Emil Kopp suggested that the two compounds were identical, and in 1866, Erlenmeyer suggested that both "cinnamol" and styrene might be vinylbenzene. They had found that cinnamic acid could be decarboxylated to form "cinnamene" (or "cinnamol"), which appeared to be styrene. Meanwhile, other chemists had been investigating another component of storax, namely, cinnamic acid. In 1865, the German chemist Emil Erlenmeyer found that styrene could form a dimer, and in 1866 the French chemist Marcelin Berthelot stated that "metastyrol" was a polymer of styrene (i.e.
Furthermore, they could obtain styrene by dry-distilling "metastyrol". They had also determined that Simon's "styrol oxide" – which they renamed "metastyrol" – had the same empirical formula as styrene.
By 1845, the German chemist August Hofmann and his student John Blyth had determined styrene's empirical formula: C 8H 8. He also noticed that when styrol was exposed to air, light, or heat, it gradually transformed into a hard, rubber-like substance, which he called "styrol oxide". He called the liquid "styrol" (now styrene). In 1839, the German apothecary Eduard Simon isolated a volatile liquid from the resin (called storax or styrax (Latin)) of the American sweetgum tree ( Liquidambar styraciflua). Styrene occurs naturally in small quantities in some plants and foods ( cinnamon, coffee beans, balsam trees and peanuts) and is also found in coal tar.
Styrene is named after storax balsam, the resin of Liquidambar trees of the Altingiaceae plant family.
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