olefin

olefin
olefinic, adj.
/oh"leuh fin/, n. Chem.
any member of the alkene series.
Also, olefine /oh"leuh fin, -feen'/.
[1855-60; < F oléf(iant) (see OLEFIANT GAS) + -IN2]

* * *

Any unsaturated hydrocarbon containing one or more pairs of carbon atoms linked by a double bond (see covalent bond, saturation).

Olefins may be classified by whether the double bond is in a ring (cyclic) or a chain (acyclic, or aliphatic) or by the number of double bonds (monoolefin, diolefin, etc.). Rare in nature, olefins are obtained by the cracking of petroleum fractions at high temperatures. The simplest ones (ethylene, propylene, butylene, butadiene, and isoprene) are the basis of the petrochemicals industry. They react by adding other chemical agents at the double bond to form derivatives or polymers.

* * *

also called  alkene 
 any unsaturated hydrocarbon containing one or more pairs of carbon atoms linked by a double bond. The olefins are classified in either or both of the following ways: (1) as cyclic or acyclic (aliphatic) olefins, in which the double bond is located between carbon atoms forming part of a cyclic (closed-ring) or of an open-chain grouping, respectively, and (2) as monoolefins, diolefins, triolefins, etc., in which the number of double bonds per molecule is, respectively, one, two, three, or some other number.

      Acyclic monoolefins have the general formula CnH2n1PT, C being a carbon atom, H a hydrogen atom, and n an integer. They are rare in nature but are formed in large quantities during the cracking (breaking down of large molecules) of petroleum oils to gasoline. The lower monoolefins—i.e., ethylene, propylene, and butylene—have become the basis for the extensive petrochemicals industry. Most uses of these compounds involve reactions of the double bond with other chemical agents. Acyclic diolefins, also known as acyclic dialkenes, or acyclic dienes, with the general formula CnH2n-2, contain two double bonds; they undergo reactions similar to the monoolefins. The best-known dienes are butadiene and isoprene, used in the manufacture of synthetic rubber.

      Olefins containing two to four carbon atoms per molecule are gaseous at ordinary temperatures and pressure; those containing five or more carbon atoms are usually liquid at ordinary temperatures. Olefins are only slightly soluble in water.

* * *


Universalium. 2010.

Игры ⚽ Поможем написать реферат

Look at other dictionaries:

  • olefin — o le*fin, olefine o le*fine([=o] l[ e]*f[i^]n or [=o] l[ e]*f[=e]n), n. [From {Olefiant}.] 1. (Chem.) Olefiant gas, or ethylene. See {Ethylene}. [archaic] [1913 Webster] 2. Hence: (Chem.) Any one of the series of unsaturated hydrocarbons of which …   The Collaborative International Dictionary of English

  • olefin — [ō′ləfin, ō′ləfēn΄ō′lə fin] n. [< Fr ( gaz) oléfiant < L oleum,OIL + prp. of Fr fier, to make < L facere: see DO1] ALKENE: also olefine [ō′ləfin, ō′ləfēn΄] olefinic [ō′ləfin′ik] adj …   English World dictionary

  • Olefin — Allgemeine Strukturformel für Alkene mit einer Doppelbindung Unter Alkenen (früher auch Olefine) werden chemische Verbindungen aus der Gruppe der Kohlenwasserstoffe verstanden, die an beliebiger Position eine oder mehrere Doppelbindungen zwischen …   Deutsch Wikipedia

  • olefin —    An alkene. An organic compound similar to an alkane, but containing at least one double bond. Olefins have the formula CnH2n. The simplest olefin is ethylene, C2H4 …   Forensic science glossary

  • olefin — alkenas statusas T sritis chemija apibrėžtis Alifatinis angliavandenilis, turintis vieną dvigubąjį ryšį. atitikmenys: angl. alkene; olefin rus. алкен; олефин ryšiai: sinonimas – etileninis angliavandenilis …   Chemijos terminų aiškinamasis žodynas

  • Olefin metathesis — or transalkylidenation is an organic reaction that entails redistribution of alkylene fragments by the scission of carbon carbon double bonds in olefins (alkenes).[1] Its advantages include the creation of fewer sideproducts and hazardous wastes …   Wikipedia

  • Olefin fiber — is a synthetic fiber made from a polyolefin, such as polypropylene or polyethylene. It is used in wallpaper, ropes, and vehicle interiors. Olefin s advantages are its strength, colourfastness and comfort, stain, mildew, abrasion and sunlight… …   Wikipedia

  • olefin series — n. ETHYLENE SERIES …   English World dictionary

  • olefin fiber — any of a group of synthetic textile fibers, as Herculon, formed from long chain polymers no less than 85 percent ethylene, propylene, or other olefin units. * * * …   Universalium

  • olefin fibre — /ˈɒləfən faɪbə/ (say oluhfuhn fuybuh) noun any of a group of synthetic textile fibres formed from long chain polymers which are at least 85 per cent olefin …  

  • olefin fiber — any of a group of synthetic textile fibers, as Herculon, formed from long chain polymers no less than 85 percent ethylene, propylene, or other olefin units …   Useful english dictionary

Share the article and excerpts

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