
Glycol ethers are a class of chemical compounds consisting of
alkyl
In organic chemistry, an alkyl group is an alkane missing one hydrogen.
The term ''alkyl'' is intentionally unspecific to include many possible substitutions.
An acyclic alkyl has the general formula of . A cycloalkyl group is derived from a cy ...
ether
In organic chemistry, ethers are a class of compounds that contain an ether group, a single oxygen atom bonded to two separate carbon atoms, each part of an organyl group (e.g., alkyl or aryl). They have the general formula , where R and R� ...
s that are based on
glycols such as
ethylene glycol
Ethylene glycol ( IUPAC name: ethane-1,2-diol) is an organic compound (a vicinal diol) with the formula . It is mainly used for two purposes: as a raw material in the manufacture of polyester fibers and for antifreeze formulations. It is an odo ...
or
propylene glycol
Propylene glycol ( IUPAC name: propane-1,2-diol) is a viscous, colorless liquid. It is almost odorless and has a faintly sweet taste. Its chemical formula is CH3CH(OH)CH2OH.
As it contains two alcohol groups, it is classified as a diol. An al ...
. They are commonly used as solvents in
paint
Paint is a material or mixture that, when applied to a solid material and allowed to dry, adds a film-like layer. As art, this is used to create an image or images known as a painting. Paint can be made in many colors and types. Most paints are ...
s and cleaners. They have good solvent properties while having higher boiling points than the lower-molecular-weight ethers and
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.
History
The name "Cellosolve" was registered in 1924 as a United States trademark by Carbide & Carbon Chemicals Corporation (a division
of
Union Carbide Corporation) for "Solvents for Gums, Resins, Cellulose Esters, and the Like". "Ethyl Cellosolve" or simply "Cellosolve" consists mainly of
ethylene glycol monoethyl ether and was introduced as a lower-cost solvent alternative to
ethyl lactate. "Butyl Cellosolve" (
ethylene glycol monobutyl ether) was introduced in 1928, and "Methyl Cellosolve" (
ethylene glycol monomethyl ether) in 1929.
Types
Glycol ethers are designated "E-series" or "P-series" for those made from
ethylene oxide
Ethylene oxide is an organic compound with the chemical formula, formula . It is a cyclic ether and the simplest epoxide: a three-membered ring (chemistry), ring consisting of one oxygen atom and two carbon atoms. Ethylene oxide is a colorless ...
or
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 ...
, respectively. Typically, E-series glycol ethers are found in pharmaceuticals, sunscreens, cosmetics, inks, dyes and water-based paints, while P-series glycol ethers are used in degreasers, cleaners, aerosol paints and adhesives. Both E- and P-series glycol ethers can be used as intermediates that undergo further chemical reactions, producing glycol diethers and glycol ether acetates. P-series glycol ethers are marketed as having lower toxicity than the E-series.
Health impacts
Most glycol ethers are water-soluble, biodegradable and only a few are considered toxic.
In the early 1990s, studies found higher than expected rates of miscarriages among women who worked in semiconductor plants, which was traced back to glycol ethers used in the photoresist substances that coat
semiconductors
A semiconductor is a material with electrical conductivity between that of a conductor and an insulator. Its conductivity can be modified by adding impurities (" doping") to its crystal structure. When two regions with different doping levels ...
.
One study suggests that occupational exposure to glycol ethers is related to low motile
sperm count, a finding disputed by the chemical industry.
Subclasses
Solvents
*
Ethylene glycol monomethyl ether (2-methoxyethanol, CH
3OCH
2CH
2OH)
*
Ethylene glycol monoethyl ether (2-ethoxyethanol, CH
3CH
2OCH
2CH
2OH)
*
Ethylene glycol monopropyl ether (2-propoxyethanol, CH
3CH
2CH
2OCH
2CH
2OH)
*
Ethylene glycol monoisopropyl ether (2-isopropoxyethanol, (CH
3)
2CHOCH
2CH
2OH)
*
Ethylene glycol monobutyl ether (2-butoxyethanol, CH
3CH
2CH
2CH
2OCH
2CH
2OH), a widely used solvent in paintings and surface coatings, cleaning products and inks
*
Ethylene glycol monophenyl ether (2-phenoxyethanol, C
6H
5OCH
2CH
2OH)
*
Ethylene glycol monobenzyl ether (2-benzyloxyethanol, C
6H
5CH
2OCH
2CH
2OH)
*
Propylene glycol methyl ether, (1-methoxy-2-propanol, CH
3OCH
2CH(OH)CH
3)
*
Diethylene glycol monomethyl ether (2-(2-methoxyethoxy)ethanol, methyl carbitol, CH
3OCH
2CH
2OCH
2CH
2OH)
*
Diethylene glycol monoethyl ether (2-(2-ethoxyethoxy)ethanol, carbitol cellosolve, CH
3CH
2OCH
2CH
2OCH
2CH
2OH)
*
Diethylene glycol mono-n-butyl ether (2-(2-butoxyethoxy)ethanol, butyl carbitol, CH
3CH
2CH
2CH
2OCH
2CH
2OCH
2CH
2OH)
*
Dipropyleneglycol methyl ether
*
C12-15 pareth-12
C12-15 pareth-12 ( INCI name) is an emulsifier and surfactant commonly used in cosmetics formulations. It is a polyethylene glycol ether formed by combining synthetic C12–C15 fatty alcohols with 12 moles of ethylene oxide.
According to t ...
a polyethylene glycol ether used as an emulsifier in cosmetics
Dialkyl ethers
*
Ethylene glycol dimethyl ether (dimethoxyethane, monoglyme, CH
3OCH
2CH
2OCH
3), a higher boiling alternative to
diethyl ether
Diethyl ether, or simply ether, is an organic compound with the chemical formula , sometimes abbreviated as . It is a colourless, highly Volatility (chemistry), volatile, sweet-smelling ("ethereal odour"), extremely flammable liquid. It belongs ...
and
THF, also used as a solvent for polysaccharides, a reagent in organometallic chemistry and in some electrolytes of
lithium batteries
*
Diethylene glycol dimethyl ether (1-Methoxy-2-(2-methoxyethoxy)ethane, diglyme, CH
3OCH
2CH
2OCH
2CH
2OCH
3)
*
Triethylene glycol dimethyl ether (2,5,8,11-Tetraoxadodecane, triglyme, CH
3OCH
2CH
2OCH
2CH
2OCH
2CH
2OCH
3)
*
Tetraethylene glycol dimethyl ether (2,5,8,11,14-Pentaoxapentadecane, tetraglyme, CH
3OCH
2CH
2OCH
2CH
2OCH
2CH
2OCH
2CH
2OCH
3)
*
Ethylene glycol diethyl ether (diethoxyethane, CH
3CH
2OCH
2CH
2OCH
2CH
3)
*
Ethylene glycol dibutyl ether (dibutoxyethane, CH
3CH
2CH
2CH
2OCH
2CH
2OCH
2CH
2CH
2CH
3)
Esters
*
Ethylene glycol methyl ether acetate (2-methoxyethyl acetate, CH
3OCH
2CH
2OCOCH
3)
*
Ethylene glycol monoethyl ether acetate (2-ethoxyethyl acetate, CH
3CH
2OCH
2CH
2OCOCH
3)
*
Ethylene glycol monobutyl ether acetate (2-butoxyethyl acetate, CH
3CH
2CH
2CH
2OCH
2CH
2OCOCH
3)
*
Propylene glycol methyl ether acetate (1-methoxy-2-propanol acetate)
References
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Commodity chemicals