Ethylene glycol (monoethylene glycol (MEG), 1,2-ethanediol, IUPAC name: ethane-1,2-diol) is an alcohol with two -OH groups (a diol), a chemical compound widely used as an automotive antifreeze. In its pure form, it is an odorless, colorless, syrupy liquid with a sweet taste. Ethylene glycol is toxic.
This reaction can be catalyzed by either acids or bases, or can occur at neutral pH under elevated temperatures. The highest yields of ethylene glycol occur at acidic or neutral pH with a large excess of water. Under these conditions, ethylene glycol yields of 90% can be achieved. The major byproducts are the ethylene glycol oligomers diethylene glycol, triethylene glycol, and tetraethylene glycol.
This molecule has been observed in space.
Minor uses of ethylene glycol include the manufacture of capacitors, as a chemical intermediate in the manufacture of 1,4-dioxane and as an additive to prevent corrosion in liquid cooling systems for personal computers.
Ethylene glycol is commonly used as a preservative for specimens in schools, frequently during dissection. It is said to be safer than formaldehyde, but the safety is questionable.
Instead of removing water ethylene glycol can also be used to depress the temperature at which hydrates are formed. The purity of glycol used for hydrate suppression (mono-ethylene glycol) is typically around 80%, whereas the purity of glycol used for dehydration (tri-ethylene glycol) is typically 95-99+%. Moreover, the injection rate for hydrate suppression is much lower than the circulation rate in a glycol dehydration tower.
Ethylene glycol is also used in the manufacture of some vaccines, but it is not itself present in these injections. It is used as a minor (1–2%) ingredient in shoe polish and also in some inks and dyes. Ethylene glycol has seen some use as a rot and fungal treatment for wood, both as a preventative and a treatment after the fact. It has been used in a few cases to treat partially rotted wooden objects to be displayed in museums. It is one of only a few treatments that are successful in dealing with rot in wooden boats, and is relatively cheap. Ethylene glycol may also be one of the minor ingredients in screen cleaning solutions, along with the main ingredient isopropyl alcohol.
The electrolysis of ethylene glycol solutions with a silver anode results in an exothermic reaction. In the Apollo 1 fire catastrophe a coolant consisting of ethylene glycol and water was implicated as a possible cause via this reaction. An ethylene glycol–water mixture can be ignited and burns in an atmosphere of pure low pressure oxygen.
When first introduced it created a minor revolution in aircraft design because when used in place of water as an engine coolant, its higher boiling point allowed for smaller radiators operating at higher temperatures. Prior to the widespread availability of ethylene glycol, many aircraft manufacturers tried to use evaporative cooling systems which used water at high pressure. Invariably, these proved to be rather unreliable and were easily damaged in combat because they took up large amounts of room on the plane, where they were easily hit by gunfire.
US Patent Issued on March 5 for "Composition for Solubilizing Tissue Comprising 3-(Decyl Dimethyl Ammonio) Propane Sulfonate and Tetraethylene Glycol Dodecyl Ether" (American, Japanese Inventors)
Mar 12, 2013; ALEXANDRIA, Va., March 12 -- United States Patent no. 8,389,582, issued on March 5."Composition for Solubilizing Tissue...
WIPO ASSIGNS PATENT TO QIAGEN FOR "PROCESS FOR AMPLIFYING DNA USING TETRAETHYLENE GLYCOL, KIT OF PARTS THEREFOR AND USE THEREOF" (GERMAN INVENTORS)
Jan 06, 2011; GENEVA, Jan. 6 -- Publication No. WO/2010/149532 was published on Dec. 29. Title of the invention: "PROCESS FOR AMPLIFYING DNA...
Synthesis and adsorption properties of macroporous cross-linked polystyrene that contains an immobilizing 2,5-dimercapto-1,3,4-thiodiazole with tetraethylene glycol spacers.
Nov 01, 2005; INTRODUCTION It is well known that mercury is an occurring toxic metal in natural ecosystems. It is commonly used in a wide...