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substance added to a solvent to lower its freezing point. The solution formed is called an antifreeze mixture. Antifreeze is typically added to water in the cooling system of an internal-combustion engine so that it may be cooled below the freezing point of pure water (32°F; or 0°C;) without freezing. Any substance that dissolves will cause freezing-point depression (see colligative propertiescolligative properties,
properties of a solution that depend on the number of solute particles present but not on the chemical properties of the solute. Colligative properties of a solution include freezing point (see freezing), boiling point, osmotic pressure (see osmosis), and
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); a desirable antifreeze also should not corrode metal parts, attack rubber, become viscous at low temperatures, or evaporate readily at the ordinary engine operating temperature. It should be chemically stable, a good conductor of heat, and a poor conductor of electricity. Ethylene glycolglycol
, dihydric alcohol in which the two hydroxyl groups are bonded to different carbon atoms; the general formula for a glycol is (CH2)n(OH)2.
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 is the most widely used automotive cooling-system antifreeze, although methanol, ethanol, isopropyl alcohol, and propylene glycol are also used. Substances that inhibit corrosion are usually added; antifoaming agents are sometimes added as well. In automotive windshield-washer fluids, an alcohol (e.g., methanol) is usually added to keep the mixture from freezing; it also acts as a solvent to help clean the glass. The brine used in some commercial refrigeration systems is an antifreeze mixture; it is typically a water solution of calcium chloride or propylene glycol.



a liquid with a low freezing point, used for cooling internal combustion engines and other equipment operating at temperatures below 0°C. The primary requirements for antifreeze are high heat capacity, thermal conductivity, boiling point, and flash point; low viscosity at low temperatures, small vapor pressure, and as little foaming as possible. In addition, antifreeze must not be very corrosive to the metals from which the cooling system parts are made and must not eat away hose and gasket materials. These requirements are met to a greater or lesser degree by aqueous solutions of ethylene glycol, glycerine, certain alcohols, and other organic compounds as well as by aqueous salt solutions (for instance, calcium chloride).

The best antifreeze materials are aqueous solutions of ethylene glycol with anticorrosion additives to prevent corrosion (such as sodium phosphate). It is possible to obtain mixtures with a freezing point as low as -75°C (66.7 percent ethylene glycol and 33.3 percent water). Upon freezing, such solutions increase in volume insignificantly (0.3 percent with a 55 to 65 percent water content) and when cooled below freezing do not rupture pipes and radiators of the cooling system.

Domestic industry manufactures brands 40 and 65 ethylene glycol antifreeze (freezing points of -40°C and -65°C, respectively) with sodium phosphate and brand 40 M with sodium molybdate.


Motornye i reaktivnye masía i zhidkosti. Edited by K. K. Papok and E. G. Semenido, 4th ed. Moscow, [1964].
Bobrov, N. N., and P. I. Voropai. Primenenie topliv i smazochnykh materialov, 2nd ed. Moscow, 1968.



A substance added to a liquid to lower its freezing point; the principal automotive antifreeze component is ethylene glycol.


a liquid, usually ethylene glycol (ethanediol), added to cooling water to lower its freezing point, esp for use in an internal-combustion engine
References in periodicals archive ?
RSPCA inspector Neill Manley said: "It may well be that the cats are drinking it accidentally, such as from a fountain or water feature with anti-freeze in to prevent the water from freezing, but in one of the cases tuna was found in the cat's vomit while the owner only fed the cat biscuits so we are considering deliberate poisoning too.
Earlier this year, The Chronicle told how five pet cats had been poisoned with anti-freeze in Ashington, just eight miles away.
In summer it is unlikely that anti-freeze is left lying around and we think that somebody is poisoning the cats because they don't like them in gardens.
Once anti-freeze gets in the blood stream the pet's condition rapidly diminishes.
According to a report in The Canadian Press, an online news source, the extract acts as a kind of modifying anti-freeze.
If you've been using Norton Utilities for years and have recently upgraded to Windows 95, you'll be pleased with the new CrashGuard and Anti-Freeze programs, which guard against crashes and application lock-ups.
Anti-freeze liquid is constantly pumped around the inside of the suit in a network of tiny tubes that lie next to the skin.
The water, which is completely separate from that in the ring main, is dyed an intense blue with anti-freeze so that the level can be more easily gauged.
Hydrogen bonds -- strong connections between hydrogen atoms and atoms belonging to other molecules -- keep anti-freeze from boiling away in overheated radiators and stabilize the kinks and folds of proteins.
Your heater and defrosters, as well as your battery and anti-freeze are also all critical components for winter driving.
Anti-freeze is another winter essential for your car because it lowers the temperature at which the water in the radiator will freeze - and if that happens, you can be in all sorts of trouble.
HUDDERSFIELD EXAMINER THURSDAY, NOVEMBER 5, 2015 9 NEWS Follow us on Twitter @examiner Three pet cats killed by anti-freeze poisoning Warning to residents over flooding risks PeOPLe are being urged to be aware of the risk of flooding in their area, and to sign up to receive warnings.