Glycol ethers
Glycol ethers are a group of organic chemicals based on ethylene glycol or diethylene glycol as the base unit. These are mainly used as solvents , especially in paints , and as a base for epoxy resins . As solvents, glycol ethers typically have the advantageous solvent properties of ethers and alcohols of lower molecular weights , but higher boiling points, which is advantageous for processing.
The trademark "Cellosolve" was established in 1924 as a US American trademark by Carbide & Carbon Chemicals Corp (later Union Carbide ) for "Solvents for Gums, Resins, Cellulose Esters, and the Like". ) registered. Since the 1970s, propylene glycol derivatives have been increasingly displacing ethylene glycol products from the market in the industrial sector. Propylene oxide is now more common than ethylene oxide due to the increasing demand for epoxy resins.
Glycol ethers
- Ethylene glycol monomethyl ether (methyl glycol , 2-methoxyethanol, CH 3 - O –CH 2 CH 2 - OH )
- Ethylene glycol monoethyl ether (ethyl glycol, 2-ethoxyethanol, CH 3 CH 2 - O –CH 2 CH 2 - OH )
- Ethylene glycol monopropyl ether (2-propoxyethanol, CH 3 CH 2 CH 2 - O –CH 2 CH 2 - OH )
- Ethylene glycol monoisopropyl ether (2-isopropoxyethanol, (CH 3 ) 2 CH– O –CH 2 CH 2 - OH )
- Ethylene glycol monobutyl ether (2-butoxyethanol, CH 3 CH 2 CH 2 CH 2 - O -CH 2 CH 2 - OH ), a widely used solvent such as in paints, surface coatings, printing inks and cleaning products
- Ethylene glycol monophenyl ether (2-phenoxyethanol, C 6 H 5 - O –CH 2 CH 2 - OH )
- Ethylene glycol monohexyl ether (2-hexyloxyethanol, C 6 H 11 - O –CH 2 CH 2 - OH )
- Ethylene glycol monobenzyl ether (2-benzyloxyethanol, C 6 H 5 CH 2 - O –CH 2 CH 2 - OH )
- Diethylene glycol monomethyl ether [2- (2-methoxyethoxy) ethanol, methyl carbitol, CH 3 - O –CH 2 CH 2 - O –CH 2 CH 2 - OH ]
- Diethylene glycol monoethyl ether [2- (2-ethoxyethoxy) ethanol, carbitol cellosolve, CH 3 CH 2 - O –CH 2 CH 2 - O –CH 2 CH 2 - OH ]
- Diethylene glycol mono-n-butyl ether [2- (2-butoxyethoxy) ethanol, CH 3 CH 2 CH 2 CH 2 - O -CH 2 CH 2 - O -CH 2 CH 2 - OH ], often-used solvents
- Diethylene glycol mono-n-hexyl ether
- Propylene glycol monomethyl ether (1-methoxy-2-propanol)
- Propylene glycol monoethyl ether (ethoxypropanol)
- Propylene glycol monobutyl ether (1-butoxy-2-propanol)
- Propylene glycol monohexyl ether (1-hexoxy-2-propanol)
- Dipropylene glycol monomethyl ether (mixture of isomers)
- Dipropylene glycol monobutyl ether (mixture of isomers)
- Dipropylene glycol monohexyl ether (mixture of isomers)
- Polyethylene glycol ether
- Polypropylene glycol ether
Dialkyl ethers
Compared with glycol monoethers, their diethers have remarkably low ignition temperatures . This requires special protective measures in chemical plants, because pipelines can reach surface temperatures of 220 ° C at certain points.
- Ethylene glycol dimethyl ether (dimethoxyethane, CH 3 OCH 2 CH 2 OCH 3 ), an alternative to diethyl ether and tetrahydrofuran in research , is also used as a solvent for polysaccharides, as a reagent in organometallic chemistry and as an electrolyte in lithium batteries .
- Ethylene glycol diethyl ether ( diethyl glycol , diethoxyethane, CH 3 CH 2 OCH 2 CH 2 OCH 2 CH 3 )
- Ethyleneglycol dibutylether (dibutoxyethane, CH 3 CH 2 CH 2 CH 2 OCH 2 CH 2 OCH 2 CH 2 CH 2 CH 3 )
- Dipropylene glycol dimethyl ether
Others
Current studies show that exposure to glycol ethers may be associated with barely motile sperm in the sperm analysis , but this finding is very controversial.
Individual evidence
- ↑ 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.
- ↑ Glycol ethers which are harmful to health and are no longer produced ( Memento of the original from December 5, 2013 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ N. Cherry, H. Moore, R. McNamee, A. Pacey, G. Burgess, JA Clyma, M. Dippnall, H. Baillie, A. Povey: Occupation and male infertility: glycol ethers and other exposures. In: Occupational and Environmental Medicine . 65, 2008, pp. 708-714, doi: 10.1136 / oem.2007.035824 .
- ↑ Peter J. Boogaard, Gerard MH Swaen: Letter to the editor on a recent publication titled "Occupation and male infertility: glycol ethers" Archived from the original on July 24, 2011. In: Occupational and Environmental Medicine . July 11, 2008.
Web links
- BASF - Solvent overview (general) (glycol ethers)
- Shell - Solvent overview (glycol ether) ( Memento from September 2, 2014 in the Internet Archive )
- DOW - Solvent overview (general)