Glycol ethers are a group of solvents based on alkyl ethers of ethylene glycol or propylene glycol commonly used in paints and cleaners. These solvents typically have a higher boiling point, together with the favorable solvent properties of lower-molecular weight ethers and alcohols. The word "Cellosolve" was registered in 1924 as a United States trademark by Carbide & Carbon Chemicals Corp. (later named Union Carbide Corp.) for "Solvents for Gums, Resins, Cellulose Esters, and the Like".[1] The first one was ethyl cellosolve (ethylene glycol monoethyl ether), with the name now generic for glycol ethers.
Glycol ethers are either "e-series" or "p-series" glycol ethers, depending on whether they are made from ethylene oxide or propylene oxide, 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-series glycol ethers 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. Most glycol ethers are water-soluble, biodegradable and only a few are considered toxic.
One study suggests that occupational exposure to glycol ethers is related to low motile sperm count,[2] a finding disputed by the chemical industry.[3]
Glycol ether solvents
- Ethylene glycol monomethyl ether (2-methoxyethanol, CH3OCH2CH2OH)
- Ethylene glycol monoethyl ether (2-ethoxyethanol, CH3CH2OCH2CH2OH)
- Ethylene glycol monopropyl ether (2-propoxyethanol, CH3CH2CH2OCH2CH2OH)
- Ethylene glycol monoisopropyl ether (2-isopropoxyethanol, (CH3)2CHOCH2CH2OH)
- Ethylene glycol monobutyl ether (2-butoxyethanol, CH3CH2CH2CH2OCH2CH2OH), a widely used solvent in paintings and surface coatings, cleaning products and inks
- Ethylene glycol monophenyl ether (2-phenoxyethanol, C6H5OCH2CH2OH)
- Ethylene glycol monobenzyl ether (2-benzyloxyethanol, C6H5CH2OCH2CH2OH)
- Propylene glycol methyl ether, (1-methoxy-2-propanol, CH3OCH2CH(OH)CH3)
- Diethylene glycol monomethyl ether (2-(2-methoxyethoxy)ethanol, methyl carbitol, CH3OCH2CH2OCH2CH2OH)
- Diethylene glycol monoethyl ether (2-(2-ethoxyethoxy)ethanol, carbitol cellosolve, CH3CH2OCH2CH2OCH2CH2OH)
- Diethylene glycol mono-n-butyl ether (2-(2-butoxyethoxy)ethanol, butyl carbitol, CH3CH2CH2CH2OCH2CH2OCH2CH2OH)
- Dipropyleneglycol methyl ether
- C12-15 pareth-12 a polyethylene glycol ether used as an emulsifier in cosmetics
Dialkyl ethers
- Ethylene glycol dimethyl ether (dimethoxyethane, CH3OCH2CH2OCH3), a higher boiling alternative to diethyl ether and THF, also used as a solvent for polysaccharides, a reagent in organometallic chemistry and in some electrolytes of lithium batteries
- Ethylene glycol diethyl ether (diethoxyethane, CH3CH2OCH2CH2OCH2CH3)
- Ethylene glycol dibutyl ether (dibutoxyethane, CH3CH2CH2CH2OCH2CH2OCH2CH2CH2CH3)
Esters
- Ethylene glycol methyl ether acetate (2-methoxyethyl acetate, CH3OCH2CH2OCOCH3)
- Ethylene glycol monoethyl ether acetate (2-ethoxyethyl acetate, CH3CH2OCH2CH2OCOCH3)
- Ethylene glycol monobutyl ether acetate (2-butoxyethyl acetate, CH3CH2CH2CH2OCH2CH2OCOCH3)
- Propylene glycol methyl ether acetate (1-methoxy-2-propanol acetate)
References
- ^ Union Carbide also registered "Cellosolve" as a trademark for "ETHYL SILICATES FOR USE AS BINDERS IN INVESTMENT CASTINGS AND IN ZINC-RICH PRIMERS" (Reg. Number 1019768, September 9, 1975), but let it expire
- ^ Nicola Cherry; Harry Moore; Roseanne McNamee; Allan Pacey; Gary Burgess; Julie-Ann Clyma; Martin Dippnall; Helen Baillie; Andrew Povey (2008). "Occupation and male infertility: glycol ethers and other exposures". Occup. Environ. Med. 65 (10): 708–714. doi:10.1136/oem.2007.035824. PMID 18417551.
- ^ Peter J Boogaard; Gerard M H Swaen (2008). "Letter to the editor on a recent publication titled "Occupation and male infertility: glycol ethers". Occup. Environ. Med. Archived from the original on 2011-07-24.