Alkoxylation is a
chemical reaction
A chemical reaction is a process that leads to the chemistry, chemical transformation of one set of chemical substances to another. When chemical reactions occur, the atoms are rearranged and the reaction is accompanied by an Gibbs free energy, ...
that involves the addition of an
epoxide
In organic chemistry, an epoxide is a cyclic ether, where the ether forms a three-atom ring: two atoms of carbon and one atom of oxygen. This triangular structure has substantial ring strain, making epoxides highly reactive, more so than other ...
to another compound. The usual manifestation of this reaction is
ethoxylation
In organic chemistry, ethoxylation is a chemical reaction in which ethylene oxide () adds to a substrate. It is the most widely practiced alkoxylation, which involves the addition of epoxides to substrates.
In the usual application, alcoh ...
of
alcohol
Alcohol may refer to:
Common uses
* Alcohol (chemistry), a class of compounds
* Ethanol, one of several alcohols, commonly known as alcohol in everyday life
** Alcohol (drug), intoxicant found in alcoholic beverages
** Alcoholic beverage, an alco ...
s (ROH), in which case ethylene oxide is the alkoxylating agent:
:ROH + C
2H
4O → ROCH
2CH
2OH
Another industrially significant epoxide is
propylene oxide
Propylene oxide is an epoxide with the molecular formula C3H6O. This colourless volatile liquid with an odour similar to ether, is produced on a large scale industrially. Its major application is its use for the production of polyether polyols f ...
(PO, OCH
2CHCH
3). PO is mainly used for alkoxylation to produce polyether polyols. The alkoxylation process is shown in simplified form:
:ROH + n OCH
2CHCH
3 → R(OCH
2CHCH
3)
nOH
Polyols derived from PO have complex stereochemistry owing to the chirality of the propylene oxide. These polyols are used on a large scale to produce polyurethanes, by condensation with
diisocyanate
In organic chemistry, isocyanate is the functional group with the formula . Organic compounds that contain an isocyanate group are referred to as isocyanates. An organic compound with two isocyanate groups is known as a diisocyanate. Diisocyan ...
s.
[Norbert Adam et al. "Polyurethanes" in Ullmann's Encyclopedia of Industrial Chemistry, 2005, Wiley-VCH, Weinheim. {{doi, 10.1002/14356007.a21_665.pub2]
References
Addition reactions