epoxide

epoxide
/e pok"suyd, i pok"-/, n. Chem.
an organic chemical that contains a group consisting of an oxygen atom bound to two already connected atoms, usually carbon (epoxy group). Cf. epoxy (def. 2).
[EP- + OXIDE]

* * *

      cyclic ether with a three-membered ring. The basic structure of an epoxide contains an oxygen atom attached to two adjacent carbon atoms of a hydrocarbon.

      The strain of the three-membered ring makes an epoxide much more reactive than a typical acyclic ether. Ethylene oxide is economically the most important epoxide and is made from oxidation of ethylene over a silver catalyst. It is used as a fumigant and to make antifreeze, ethylene glycol, and other useful compounds.

      More-complex epoxides are commonly made by the epoxidation of alkenes (olefin), often using a peroxyacid (RCO3H) to transfer an oxygen atom.

      Another important industrial route to epoxides requires a two-step process. First, an alkene is converted to a chlorohydrin, and second, the chlorohydrin is treated with a base to eliminate hydrochloric acid, giving the epoxide; this is the method used to make propylene oxide.

      Epoxides are easily opened, under acidic or basic conditions, to give a variety of products with useful functional groups (functional group). For example, the acid- or base-catalyzed hydrolysis of propylene oxide gives propylene glycol.

      Epoxides can be used to assemble polymers (polymer) known as epoxies, which are excellent adhesives and useful surface coatings. The most common epoxy resin is formed from the reaction of epichlorohydrin with bisphenol A.

Leroy G. Wade, Jr.
 

* * *


Universalium. 2010.

Look at other dictionaries:

  • Epoxide — Epoxide,   nach der systematischen chemischen Nomenklatur Oxirane, sehr reaktionsfähige organische Verbindungen, die einen dreigliedrigen Ring mit einem Sauerstoffatom die (Epoxidgruppe) enthalten. Die Epoxide werden z. B. aus Chlorhydrinen durch …   Universal-Lexikon

  • epoxide — [ep äk′sīd΄] n. a compound containing the epoxy group …   English World dictionary

  • Epoxide — A generic epoxide. An epoxide is a cyclic ether with three ring atoms. This ring approximately defines an equilateral triangle, which makes it highly strained. The strained ring makes epoxides more reactive than other ethers. Simple epoxides are… …   Wikipedia

  • Epoxide — Ethylenoxid mit der blau markierten Oxiran Gruppe. Die Epoxide (auch „Epoxyde“, nach dem Hantzsch Widman System Oxirane) oder Oxacyclopropane (nach der Austauschnomenklatur) sind in der Chemie eine Stoffgruppe sehr reaktionsfähiger, cyclischer,… …   Deutsch Wikipedia

  • epoxide — epoksidas statusas T sritis chemija apibrėžtis Oksirano darinys. atitikmenys: angl. alkene oxide; epoxide rus. окись алкена; эпоксид ryšiai: sinonimas – alkeno oksidas …   Chemijos terminų aiškinamasis žodynas

  • epoxide — noun Date: 1930 an epoxy compound …   New Collegiate Dictionary

  • epoxide — noun Any of a class of organic compound, cyclic ethers, having a three membered ring; they are prepared by the selective oxidation of alkenes or by ring closure of halohydrins; used to make plastics. Syn: alkylene oxide …   Wiktionary

  • epoxide — epox·ide (ə pokґsīd) an organic compound containing a reactive group resulting from the union of an oxygen atom with two other atoms, usually carbon, that are themselves joined together. Commonly referred to as epoxy. See also epoxy… …   Medical dictionary

  • epoxide — n. (Chemistry) epoxy compound; chemical compound of oxygen and carbon …   English contemporary dictionary

  • epoxide — [ɪ pɒksʌɪd] noun Chemistry an organic compound whose molecule contains a three membered ring involving an oxygen atom and two carbon atoms. Origin 1930s: from epi + oxide …   English new terms dictionary

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”