GENERAL INFORMATION

The internal combustion engine must be cooled to ensure the normal thermal operation of its components and parts. The most common cooling systems with forced circulation of fluid. During operation, it can heat up to 100 ° C and sometimes more, and cool down to ambient temperature in the parking lot. The efficiency of the cooling system, the reliability and durability of the engine largely depend on the properties of the liquid. It must have a high heat capacity, thermal conductivity, boiling point, mobility, as well as a low crystallization temperature and coefficient of volumetric expansion. The coolant must not cause corrosion of metals, destroy the rubber seals and foam during operation.
Water has the greatest cooling capacity, has the maximum heat capacity, fireproof, non-toxic and cheap. But water has a relatively low boiling point and evaporates relatively quickly, and if at the same time it is hard (contains mineral impurities and dissolved salts), then scale is actively formed. At temperatures below 0°C, water freezes and turns into ice (crystallizes) with a significant, up to 10% increase in volume. This leads to the "defrosting" of the engine - the destruction of its main parts and assemblies. Therefore, it cannot be used in the cold season without draining from the car during long-term parking outside a warm garage.
Low freezing coolants - antifreezes(from the English "antifreeze" - non-freezing) replaced water in the cooling systems of modern car engines. The most widely used low-freezing fluids based on glycol, which are a mixture of ethylene glycol with water. Sometimes there are liquids based on propylene glycol - they cannot be mixed with ethylene glycol.

COMPOSITION AND PROPERTIES OF ANTIFREEZE

Ethylene glycol (monoethylene glycol)- oily yellowish liquid, odorless, moderately viscous, with a density of 1.112-1.113 g/cm3 (at 20°C), a boiling point of 197°C and crystallization of -11.5°C. When heated, ethylene glycol and its aqueous solutions expand greatly. To prevent the ejection of liquid from the cooling system, it is equipped with an expansion tank and filled to 92–94% of the total volume.
An aqueous solution of ethylene glycol is chemically aggressive and causes corrosion of steel, cast iron, aluminum, copper and brass parts of the cooling system, as well as solders used for soldering its components. In addition, ethylene glycol is highly toxic.
propylene glycol- similar in properties to ethylene glycol and less toxic, but about 10 times more expensive. At low temperatures, it is more viscous than ethylene glycol, and therefore pumpability is poorer.
A mixture of ethylene glycol and water characterized by the fact that the temperature of its crystallization depends on the ratio of these two components. In a mixture, it is significantly lower than separately for water and ethylene glycol. At various proportions, solutions with a crystallization temperature from 0 to -75°C can be obtained. The temperature of crystallization and boiling, as well as the density of a mixture of ethylene glycol and water, depending on the content of ethylene glycol in it, are shown in the figure. The lowest freezing point value corresponds to a composition in which ethylene glycol is 66.7% and water is 33.3%. In other cases, the same freezing point can be obtained with two ratios of ethylene glycol and water. It is economically advantageous to use the option with a large amount of water.
Determination of the ratio of ethylene glycol and water in antifreeze is carried out according to the density measured using a hydrometer or hydrometer. On special instruments, for convenience, instead of a density scale, a double scale is used, which simultaneously shows the percentage of ethylene glycol and the crystallization temperature. When checking, it is necessary to take into account the temperature corrections to the readings of the device indicated in the instructions for it.

Additive complex includes anticorrosive, antifoaming, stabilizing and coloring agents. Antifreezes should not contain nitrite-nitrates in their composition, which, interacting with amines, form toxic compounds, some of which are carcinogenic (causing cancer).
Requirements for antifreeze in Russia installed in accordance with GOST 28084-89 “Low-freezing cooling fluids. General technical conditions". The standard normalizes the main indicators of ethylene glycol-based coolants: appearance, density, crystallization onset temperature, corrosive effect on metals, foaming, rubber swelling, etc. Coolants are not subject to mandatory certification.
Certain brands of ready-to-use antifreezes and concentrates that require dilution with distilled water before use are produced according to specifications that specify the composition and presence of additives, miscibility of liquids and their color. Manufacturers assign them various names, for example, “Tosol”, “Lena”, “Lada”, “Antifreeze G-48” and (or) indicate the crystallization temperature: OZH-40, OZH-65, A-40.
"TOSOL"- one of the names of antifreeze, formed from two parts:
"TOS"- "Technology of organic synthesis" (the name of the department of GosNIIOKhT that created the antifreeze);
"OL"- the ending characteristic of alcohols (ethanol, butynol, methanol).
This antifreeze was developed in 1971 at the State Research Institute of Organic Chemistry and Technology (GosNIIOKhT) for VAZ cars to replace the Italian PARAFLU. The trademark "TOSOL" was not registered, so it is used by many domestic manufacturers of coolants. But the performance properties of "antifreeze" can be different, since they are determined by the additives used, and they differ from different manufacturers.
Coolant Compatibility determined by the specifications. Fluids made according to different specifications are often incompatible, since the additives they contain can react with each other and lose their useful properties. Therefore, if necessary, restore the coolant level, it is better to add distilled water.
Requirements for foreign-made antifreezes are generally defined by ASTM (American Association for Testing and Materials) and SAE (Society of Automotive Engineers of the USA) standards. These standards regulate the properties of concentrates and antifreeze based on their basis (ethylene glycol or propylene glycol) and operating conditions. For example, ethylene glycol fluids are designed for: ASTM D 3306 and ASTM D 4656 for passenger cars and light trucks;
according to ASTM D 4985 and ASTM D 5345 - for engines operating in severe conditions: long-term operation in modes close to maximum power, on off-road vehicles, large trucks, in stationary power plants, etc. These liquids differ in that a special additive must be added to them before use.
Imported antifreezes according to ASTM D 3306 can be used for domestic passenger cars.
Manufacturer Specifications vehicles may contain additional requirements. For example, General Motors USA standards - Antifreeze Concentrate GM 1899-M, GM 6038-M or Volkswagen Group G standards prohibit the use of corrosion inhibitors containing nitrites, nitrates, amines, phosphates in antifreeze and stipulate maximum permissible concentrations of silicates, borax, chlorides. This reduces scale deposits, increases seal life, and improves corrosion protection.

REPLACING ANTIFREEZE

Planned replacement necessary because even during normal operation, the content of additives in the antifreeze gradually decreases and the corrosion of engine parts increases. The liquid foams more, therefore, it transfers heat worse and the motor may overheat. As a rule, a scheduled replacement is recommended after two years, and with intensive use - every 60 thousand km. car mileage.
Early replacement may be required when exhaust gases enter the cooling system, for example, through a faulty head gasket, or air at leaks, which leads to accelerated aging of the fluid. Signs of this need may include:
- a jelly-like mass forms on the inner surface of the expansion tank;
- in light frost (down to -15 ° C), the antifreeze becomes mushy and sediment is found in the tank;
- the electric fan of the radiator of the cooling system works more and more often.
In an emergency, for example, when replacing a broken hose on a long journey, water has to be poured into the cooling system from a random source. Hard water with impurities activates corrosion and causes the formation of foreign suspension, which slows down the circulation of the liquid and can make it difficult for the water pump to work. In addition, in places of strong heating, scale forms, which impairs the operation of the cooling system. If the antifreeze has turned brown, it means that active corrosion of the parts of the cooling system occurs. Coolant diluted with low-quality water should be replaced as soon as possible with mandatory flushing of the cooling system.

The procedure for replacing the coolant (carried out on a cold engine):
- remove the cover of the expansion tank and (or) the radiator;
- open the tap of the heater radiator so that there is no liquid left in it or in the supply hoses;
- unscrew the plugs in the radiator and the engine block, drain the old coolant into the substituted container, then install the drain plugs back;
- slowly pour new coolant through the expansion tank in a thin stream and close its cap;
- start the engine, warm it up, then stop it and after cooling, if necessary, add liquid to the desired level.

FLUSHING THE COOLING SYSTEM

Scheduled replacement of antifreeze it is enough to rinse the system once with distilled or, in extreme cases, well-boiled, melted or rain water.
When changing from water to antifreeze, replacing with brown or with signs of premature aging of the coolant, it is necessary to remove scale and corrosion products. This can only be done using special detergents in accordance with the instructions for them. Washes are aqueous solutions of weak acids - formic, oxalic, hydrochloric with the addition of corrosion inhibitors. Then, the remaining detergent composition should be removed by flushing the system at least once with distilled water.

The order of flushing the cooling system:
- drain the coolant and fill in the flushing fluid instead, in the same way as it is done when replacing the fluid;
- let the engine run for 20 to 60 minutes - the dirtier the drained coolant was, the more time is required to flush the system;
- stop the engine, drain the washing liquid, flush the system with distilled water and fill in fresh antifreeze.

The level of antifreeze in the expansion tank may become less than normal due to the evaporation of water from it or due to system leaks. In the first case, you need to add distilled water, and if it is not there, boiled water for 30 minutes. In case of leaks, add coolant, preferably of the same brand.
Purchase for topping up or replacing should be a coolant approved by the vehicle manufacturer, and it is better in stores, and not from a temporary tray on the street.
concentrates cannot be used in the engine cooling system - they consist of ethylene glycol with additives and a small amount of water, therefore they have a crystallization temperature of -11.5 ° C or slightly lower. They are intended only for the preparation of antifreeze by diluting the concentrate with distilled water. How much to add to get the desired freezing point of the coolant should be indicated in the instructions.
canister with antifreeze should inspire confidence in the manufacturer. A good product is rarely packaged carelessly. The container, as a rule, is closed with a cork with a disposable "ratchet", sometimes additionally protected by a "seal" - a label or tape. They should be intact, not glued, and the toothed ring on the cork should be in close contact with the neck. The tightness of the canister can be checked by turning it over or slightly squeezing it from the sides. If there is a leak or the canister is not elastic (the outgoing air hisses), it is better not to buy this. Translucent canisters are good because you can see their contents. Turbid coolant, especially with sediment, is not necessary to buy. If you shake the canister, the resulting foam should settle in about three seconds, for the concentrate - after five.
Label quality goods are usually well made and glued. The barcode, drawings, letters and numbers on it are clear, not forked or vague. The information is complete, not advertising, but mostly technical: the name of the manufacturer, its address and telephone number, annotation for the use of antifreeze, its boiling and freezing point, shelf life, batch number with date of manufacture, etc.

Attention! Ethylene glycol is poisonous and can penetrate the body even through the skin. It tastes sweet and should be kept out of the reach of children. Spilled ethylene glycol poses a certain danger to animals. When ingested, the lethal dose for humans can be as low as 35 cm3.

In modern gasoline and diesel engines, either ready-to-use antifreezes or concentrates are used as coolant, which must be diluted with water in a certain proportion. Antifreeze protects the car engine from overheating and keeps all elements of the cooling system in working order. During operation, the liquid loses some of its properties, changes in color and composition and needs to be replaced.

1 What is antifreeze used for?

To ensure the normal operation of the engine and other components of the system, high-quality cooling is necessary. At the present stage, the most common systems are forced continuous cooling with constant circulation of liquid. During engine operation, antifreeze can heat up to 120–140 degrees, and during parking it can take on ambient temperature. Thus, it is the composition and properties of the liquid that determine the efficiency of the cooling system and the degree of reliability of the engine. High-quality antifreeze should have:

• high degree of heat capacity and thermal conductivity,
• optimal ,
• lowest freezing point
• low expansion ratio,
• high fluidity.

Antifreeze should not contribute to the corrosion of metals, foam and destroy other elements of the cooling system. Almost all modern cooling fluids are made on the basis of ethylene glycol with the addition of water and various additives. However, propylene glycol-based antifreezes are also found. Mixing these two types of coolant with each other is strictly not recommended!

2 Composition and basic properties of antifreeze

Monoethylene glycol is an odorless yellow liquid with a moderate degree of viscosity with a boiling point of up to 198 degrees and a crystallization onset temperature of -11.5. When heated, monoethylene glycol mixed with water expands very much, so modern ones are equipped with a special expansion tank, which must be filled with liquid by 92–95% of the maximum volume.

It should be understood that the ethylene glycol-based aqueous solution itself is chemically toxic and corrosive and adversely affects steel, cast iron, aluminum and other surfaces of the cooling system.

Propylene glycol is a substance that is approximately equivalent in properties, which has a lower toxicity index and a higher viscosity at low temperatures. Because of this, the fluidity of propylene glycol-based antifreeze and water is slightly lower in winter, so this mixture is used less frequently.

Thus, when mixing ethylene or propylene glycol with water in certain proportions, you can get a universal liquid with a freezing point of up to -80 degrees. Typically, antifreeze is 42-45% water. Such a composition is most beneficial to manufacturers from an economic point of view. The ratio of water and ethylene glycol is determined using hydrometer or hydrometer instruments, which indicate the percentage density of liquids on a special scale.

Antifreeze additives are a complex of anti-foam, anti-corrosion, coloring, stabilizing and other substances that are added to reduce toxicity and prevent negative effects on metal, rubber, plastic and other surfaces in the fluid circulation system.

Modern international regulations prohibit the use of nitrites and nitrates in antifreezes, since when interacting with amines contained in liquids, they form dangerous toxic compounds.

3 Regulations for the production of coolant

In our country, the requirements for the composition of the coolant are standardized in accordance with GOST 28084-89. The standard prescribes the main indicators of antifreeze and antifreeze, which is allowed for use: appearance, temperature conditions (freezing, boiling point), density, foaming, degree of corrosive effect, etc. Coolants are not subject to mandatory certification, while manufacturers are required to indicate all of the above properties on product labels or instructions for use. Most fluids are produced according to regulated quality standards, which specify the amount of additives, their composition, properties, etc.

As for the antifreeze of European and American production, the production requirements are regulated by international quality standards SAE and ASTM. These standards spell out the basic requirements for the quality and composition of the liquid, depending on what the antifreeze consists of (ethylene glycol or propylene glycol). These standards mandate the use of ethylene glycol based fluids for passenger cars and light trucks only (ASTM D4576). Other standards provide for the composition of antifreeze that is used on engines of heavy equipment, large-tonnage trucks, in industrial environments, etc.). The antifreeze composition in this case has several additional complex additives. Thus, ASTM D4576 coolants can be used for passenger cars in our country.

There is also the concept of a manufacturer's specification, when a particular car manufacturer imposes additional requirements on the antifreeze used on engines of this brand. For example, General Motors or Volkswagen regulations prohibit the use of nitrates, amines, phosphates, corrosion inhibitors, as well as silicates and chlorides. This restriction, according to the engineers of these companies, allows you to increase the life of the engine and cooling system by reducing scale deposits and corrosive attack.

No less important than the brand of fuel for the engine. Knowledge of the composition and types will help drivers choose a high-quality and, most importantly, suitable coolant for a car. What are the types, what is the difference between the composition of antifreeze and antifreeze - readers will learn all this after studying this material.

The composition of antifreeze for a car and its types

Organic and inorganic antifreezes

Today, coolant can be divided into two types - silicate and carboxylate antifreeze. As for silicate, “Tosol” refers to it. The composition of such a coolant includes inorganic acids, borates, silicates, phosphates, nitrates and nitrites. Silicates are the main additive in inorganic coolant. Such antifreeze is not suitable for modern cars, as it has many disadvantages. Made from ethylene glycol.

Additives settle on the inner surface of pipelines, their main task is to provide corrosion protection and normal conductivity. Antifreeze copes with the first task perfectly, and with the second - exactly the opposite. Due to the low thermal conductivity, heat transfer is very sluggish, which results in frequent overheating of the motor. That is why it is not recommended to use antifreeze on foreign cars, since engine wear occurs too quickly. There is another serious drawback - you need to change the silicate antifreeze every 30 thousand kilometers, otherwise, in addition to overheating, corrosion will also appear inside the cooling system.

As for carboxylate antifreezes, they use only organic acids. That is why this type has significantly fewer drawbacks than the silicate version. Organic additives cover only those areas where corrosion occurs, so heat transfer is practically not lost. This is the main advantage over silicate antifreeze. Carboxylate antifreeze is made based on ethylene glycol or propylene glycol.

It was the carboxylate liquid that began to be called antifreeze after it began to be supplied to the CIS. But many today call it antifreeze. The task of the motorist is to choose the appropriate type for his car. If this is an old domestic car, then antifreeze will not get worse, and it costs much less than organic antifreeze. In other cases, you need to purchase carboxylate coolant. As for the replacement of antifreeze, it is required only after 200 thousand kilometers. It was also possible to achieve such a long period by adding organic additives.

Antifreeze classification

To date, there are three classes of antifreeze:

• Class G11. Has a green or blue color. This class includes the cheapest fluids that are on the automotive market. The composition of antifreeze G11 is as follows: ethylene glycol, silicate additives. It is to this lower class that domestic antifreeze belongs. Silicate additives give antifreeze lubricating, anti-corrosion and anti-foam properties. As mentioned above, the service life of such antifreeze is quite low - about 30 thousand kilometers.
• Class G12. Most often it is red or pink antifreeze. Higher level of quality. Such a liquid serves much longer, has more useful properties, but the price of G12 is higher than that of G11. G12 antifreeze contains organic additives and ethylene glycol.
• Class G13(formerly G12+). Has an orange or yellow color. This class includes environmentally friendly coolants. They decompose quickly and do not harm the environment. This result became available after propylene glycol was added to G12 antifreeze, while carboxylase remained as additives. Any antifreeze based on ethylene glycol will be more toxic than the equivalent based on propylene glycol. The only disadvantage of the G13 is the high cost. Most environmentally friendly G13 is common in European countries.

Popular brands of antifreeze

We figured out the classification, now you can go through the well-known brands that drivers prefer throughout the CIS. These include:

• Felix.
• Alaska.
• nord.
• Syntec.

These are the best options in terms of price / quality ratio. So, let's start with "Felix" - this antifreeze is designed for all trucks and cars. Able to function normally in severe climatic conditions. Felix antifreeze contains special patented additives that extend the life of the cooling system pipelines, protect the engine from freezing and overheating. The composition of Felix antifreeze contains anti-foam, anti-corrosion and lubricating additives, the liquid belongs to the optimal class G12.

Composition and properties of Felix antifreeze

If we talk about high-quality liquids that belong to Tosol (G11 based on inorganic additives), then this is Alaska. The emphasis in this product is on fighting the cold. For example, a certain composition of Alaska antifreeze can withstand temperatures down to -65 ° C. There are options for warm regions, where in winter the thermometer needle does not fall below 25 ° C. Of course, the types of antifreeze marked G11 have their drawbacks.

Composition and properties of antifreeze Alaska

Another good option is NORD antifreeze. The company supplies all types of coolant to the automotive market - from G11 to G13, so it makes no sense to describe the composition of NORD antifreeze.

And the last option we'll look at is automotive antifreeze Sintec. The company is mainly engaged in the production of class G12 liquids. Antifreeze is great for all modern engines. Many professional repairmen recommend using this company's antifreeze for those drivers who drive cars with an aluminum engine. The composition of Sintec antifreeze includes the company's patented additives, they perfectly protect the system from the formation of deposits in the water pump, various channels, engine compartment and radiator. Sintec also reliably protects the cooling system from corrosion.

The composition and properties of antifreeze sintek

Ethylene glycol (1,2-ethanediol, 1,2-dioxyethane, glycol) is the base substance for the manufacture of various antifreezes that are used in vehicle engine cooling systems.

Ethylene glycol is a toxic dihydric alcohol

The chemical formula of this simplest polyhydric alcohol is C2H6O2 (otherwise it can be written as follows - HO-CH2-CH2-OH). Ethylene glycol has a slightly sweet taste, odorless, in a purified state it looks like a slightly oily, colorless transparent liquid.

Since it is classified as a toxic compound (according to the generally accepted classification, it is the third hazard class), the ingress of this substance (in solutions and in pure form) into the human body should be avoided. The main chemical and physical properties of 1,2-dioxyethane:

• molar mass - 62.068 g / mol;
• optical refractive index - 1.4318;
• ignition temperature - 124 degrees (upper limit) and 112 degrees (lower limit);
• self-ignition temperature - 380 °C;
• freezing point (one hundred percent glycol) - 22 ° C;
• boiling point - 197.3 ° C;
• density - 11.113 g / cubic centimeter.

Vapors of the described dihydric alcohol flare up at the moment when its temperature reaches 120 degrees. We recall once again that 1,2-ethanediol has a 3rd hazard class. And this means that its maximum permissible concentration in the atmosphere can be no more than 5 milligrams / cubic meter. If ethylene glycol enters the human body, irreversible negative phenomena can develop in it, which can lead to death. With a single ingestion of 100 or more milliliters of glycol, a fatal outcome occurs.

Vapors of this compound are less toxic. Since ethylene glycol is characterized by a relatively low volatility index, a real danger to a person arises when he systematically inhales vapors of 1,2-ethanediol. The fact that there is a possibility of poisoning with vapors (or mists) of the compound in question is indicated by coughing and irritation of the mucous membrane. If a person is poisoned by glycol, they should take a drug containing 4-methylpyrazole (a powerful antidote that inhibits the enzyme alcohol dehydrogenase), or ethanol (monohydric ethyl alcohol).

The use of glycol in various fields of technology

The low cost of this polyhydric alcohol, its special chemical and physical properties (density and others) have led to the fact that it is used very widely in various technical fields.

Any motorist knows what is the usual coolant for his "iron horse" called antifreeze - ethylene glycol 60% + water 40%. Such a mixture is characterized by a freezing point of -45 degrees, it is very difficult to find a more suitable liquid for automotive cooling systems, despite the high hazard class of 1,2-ethanediol.

In the automotive industry, ethylene glycol is also used as an excellent coolant. In addition, it is used in the following areas:

• organic synthesis: the chemical properties of glycol make it possible to protect isophorone and other carbonyl groups with its help, use alcohol as an effective solvent operating at elevated temperatures, and also as the main component of a special aviation fluid that reduces the phenomenon of flooding of combustible mixtures for aircraft;
• dissolution of coloring compounds;
• the manufacture of nitroglycol, a powerful explosive based on the compound we are describing;
• gas industry: glycol prevents the formation of methane hydrate on pipes, in addition, it absorbs excess moisture on pipelines.

Ethylene glycol has also been used as an effective cryoprotectant. It is used in the production of shoe polishes, as an important element in computer cooling liquids, in the manufacture of 1,4-dioxin and various types of capacitors.

Some nuances of glycol production

In the late 1850s, the French chemist Wurtz obtained ethylene glycol from its diacetate, and a little later by hydration of ethylene oxide. But at that time, the new substance did not find practical application anywhere. It was only in the 1910s that it began to be used in the manufacture of explosive compounds. The density of glycol, its other physical properties and the cheapness of production led to the fact that they replaced the glycerin that was used before.

The special properties of 1,2-ethanediol were appreciated by the Americans. It was they who established its industrial production in the mid-1920s at a specially built and equipped plant in West Virginia. In subsequent years, glycol was used by almost all the companies known at that time that were engaged in the production of dynamite. At present, the compound of interest to us, which has the third hazard class, is manufactured using the ethylene oxide hydration technology. There are two options for its production:

• with the participation of phosphoric or sulfuric acid (up to 0.5 percent) at a temperature of 50 to 100 ° C and a pressure of one atmosphere;
• at a temperature of about 200 ° C and a pressure of ten atmospheres.

As a result of the hydration reaction, up to 90 percent pure 1,2-dioxyethane, a certain amount of polymer homologues and triethylene glycol are formed. The second compound is added to hydraulic and, it is used in industrial air cooling systems, it is used to make preparations for disinfection, as well as plasticizers.

The most important requirements of GOST 19710 for finished glycol

Since 1984, GOST 19710 has been in force, which establishes requirements for what properties (freezing point, density, and so on) should have ethylene glycol used in automotive enterprises and in other sectors of the economy, where various compositions are produced on its basis.

According to GOST 19710, glycol (as a liquid) can be of two types: first grade and premium. The share (mass) of water in glycol of the first grade should be up to 0.5%, the highest - up to 0.1%, iron - up to 0.00005 and 0.00001%, acids (in terms of acetic acid) - up to 0.005 and 0 .0006%. The residue after calcination of the finished product cannot be more than 0.002 and 0.001%.

Color of 1,2-dioxyethane according to GOST 19710 (according to the Hazen scale):

• after boiling in an acid solution (hydrochloric) - 20 units for products of the highest grade (the first grade is not standardized by color);
• in the standard condition - 5 (highest grade) and 20 units (first grade).

The State Standard 19710 puts forward special requirements for the production process of the described simplest alcohol:

• only sealed apparatus and equipment is used;
• the production room must be equipped with ventilation recommended for working with compounds that are assigned the third hazard class;
• If glycol gets on the equipment or the ground, it should be washed off immediately with plenty of water;
• personnel working in the workshop for the production of 1,2-ethanediol are provided with a BKF model gas mask or other respiratory protection device that complies with GOST 12.4.034;
• glycol fires are extinguished with inert gases, special foam formulations, and water mist.

Finished products according to GOST 19710 are checked by various methods. For example, the mass fraction of dihydric alcohol and diethylene glycol is determined by the method of isothermal gas chromatography using the technology of the so-called "internal standard". In this case, scales for laboratory research (GOST 24104), a glass or steel gas chromatographic column and a chromatograph with an ionization-type detector, a measuring ruler, a microsyringe, an optical magnifier (GOST 25706), an evaporating cup and other tools are used.

The color of the glycol is set according to standard 29131 using a stopwatch, a special cylinder, a conical flask, hydrochloric acid, a refrigeration unit. The mass fraction of iron is determined according to State Standard 10555 using the method of sulfacyl photometry, the residue after calcination is determined according to State Standard 27184 (by evaporating the resulting compound in a platinum or quartz container). But the mass fraction of water is determined by electrometric or visual titration using Fisher's reagent in burettes with a capacity of 10 or 3 cubic centimeters.

Antifreeze - glycol based coolant

Antifreeze based on the simplest multivolume alcohol is used in modern vehicles to cool their engines. Its main component is ethylene glycol (there are formulations with propylene glycol as the main component). The additives are distilled water and special additives that give antifreeze fluorescent, anti-cavitation, anti-corrosion, anti-foam properties.

The main characteristic of antifreezes is a low freezing point. In addition, they have a low rate of expansion upon freezing (compared to 1.5-3 percent less than ordinary water). At the same time, this special glycol-based coolant is characterized by a high boiling point, which improves the operation of the vehicle in the hot season.

In general, a glycol-water based engine coolant has the following advantages:

• the absence of harmful additives (amines, various nitrites that adversely affect the nature of phosphates);
• the ability to select the required concentration of antifreeze for high-quality protection against freezing;
• stable parameters and properties throughout the entire service life;
• compatibility with those parts of the auto cooling system that are made of plastic or rubber;
• high antifoam performance.

Among other things, modern antifreezes provide anti-corrosion protection of metal alloys and metals present in an internal combustion engine due to the presence of special inhibitory additives in them.

Antifreeze - a coolant based on ethylene or propylene glycol, translated "Antifreeze", from international English, as "non-freezing". Class G12 antifreeze is intended for use on cars from 96 to 2001, modern cars usually use 12+, 12 plus plus or g13 antifreezes.

“The key to stable operation of the cooling system is high-quality antifreeze”

What is the feature of G12 antifreeze

Antifreeze with class G12, as a rule, is painted in red or pink colors, and also, compared to antifreeze or G11 antifreeze, has a longer service life - from 4 to 5 years. G12 does not contain silicates in its composition, it is based on: ethylene glycol and carboxylate compounds. Thanks to the additive package, on the surface inside the block or radiator, localization of corrosion occurs only where it is needed, forming a resistant micro film. Often this type of antifreeze is poured into the cooling system of high-speed engines. Mix antifreeze g12 and coolant of another class - unacceptable.

But he has one big minus - G12 antifreeze begins to act only when a center of corrosion has already appeared. Although this action eliminates the appearance of a protective layer and its rapid shedding as a result of vibrations and temperature changes, which makes it possible to improve heat transfer and longer use.

Main technical characteristics of class G12

Represents homogeneous transparent liquid without mechanical impurity of red or pink color. G12 antifreeze is ethylene glycol with the addition of 2 or more carboxylic acids, does not form a protective film, but affects already formed corrosion centers. The density is 1.065 - 1.085 g/cm3 (at 20°C). The freezing point is within 50 degrees below zero, and the boiling point is about +118°C. Temperature characteristics depend on the concentration of polyhydric alcohols (ethylene glycol or propylene glycol). Often, the percentage of such alcohol in antifreeze is 50-60%, which allows you to achieve optimal performance. Pure, without any impurities, ethylene glycol is a viscous and colorless oily liquid with a density of 1114 kg / m3 and a boiling point of 197 ° C, and freezes at 13 ° C minutes. Therefore, a dye is added to the antifreeze to give individuality and greater visibility of the liquid level in the tank. Ethylene glycol is the strongest food poison, the effect of which can be neutralized with ordinary alcohol.

Remember that coolant is deadly to the body. For a fatal outcome, 100-200 g of ethylene glycol will be enough. Therefore, antifreeze should be hidden from children as far as possible, because a bright color that looks like a sweet drink is of great interest to them.

What does G12 antifreeze consist of

The composition of the antifreeze class G12 concentrate includes:

• dihydric alcohol ethylene glycol about 90% of the total volume that is needed to prevent freezing;
• distilled water, about five percent;
• dye(color often identifies the class of coolant, but there may be exceptions);
• additive package at least 5 percent, since ethylene glycol is aggressive to non-ferrous metals, several types of phosphate or carboxylate additives based on organic acids are added to it, acting as an inhibitor, allowing them to neutralize the negative impact. Antifreezes with a different set of additives perform their function in different ways, and their main difference is in the methods of combating corrosion.

In addition to corrosion inhibitors, the set of additives in the G12 coolant includes additives with other necessary properties. For example, the coolant must have anti-foaming, lubricants and compositions that prevent the appearance of scale.

What is the difference between G12 and G11, G12+ and G13

The main types of antifreezes, such as G11, G12 and G13, differ in the type of additives used: organic and inorganic.

General information about antifreezes, what is the difference between them and how to choose the right coolant

Cooling class G11 liquid of inorganic origin with a small set of additives, the presence of phosphates and nitrates. Such antifreeze was created using silicate technology. Silicate additives cover the internal surface of the system with a continuous protective layer, regardless of the presence of corrosion areas. Although such a layer protects already existing centers of corrosion from destruction. Such antifreeze has low stability, poor heat transfer and a short service life, after which it precipitates, forming an abrasive and thereby damaging.

Due to the fact that G11 antifreeze creates a layer similar to scale in a kettle, it is not suitable for cooling modern cars with radiators with thin channels. In addition, the boiling point of such a cooler is 105 ° C, and the service life is no more than 2 years or 50-80 thousand km. run.

Often G11 antifreeze turns green or blue colors. This coolant is used for vehicles manufactured before 1996 years and machines with a large volume of the cooling system.

G11 is not well suited to aluminum heatsinks and blocks as its additives cannot adequately protect this metal at high temperatures.

In Europe, the authoritative specification of antifreeze classes belongs to the Volkswagen concern; therefore, the corresponding VW TL 774-C marking provides for the use of inorganic additives in antifreeze and is designated G 11. The VW TL 774-D specification provides for the presence of organic-based carboxylic acid additives and is labeled as G 12. The VW TL 774-F and VW TL 774-G standards mark the G12 + and G12 ++ classes, and the most complex and expensive G13 antifreeze is regulated by the VW TL 774-J standard. Although other manufacturers such as Ford or Toyota have their own quality standards. By the way, there is no difference between antifreeze and antifreeze. Tosol is one of the brands of Russian mineral antifreeze, which is not designed to work in engines with an aluminum block.

It is absolutely impossible to mix organic and inorganic antifreezes, since a coagulation process will occur and as a result a precipitate will appear in the form of flakes!

A liquid grades G12, G12+ and G13 varieties of organic antifreeze Long Life. Used in cooling systems of modern cars manufactured since 1996 G12 and G12+ based on ethylene glycol but only G12 plus involves the use of hybrid technology production in which silicate technology was combined with carboxylate technology. In 2008, the G12 ++ class also appeared, in such a liquid, an organic base is combined with a small amount of mineral additives (called lobrid Lobrid or SOAT coolants). In hybrid antifreezes, organic additives are mixed with inorganic additives (silicates, nitrites and phosphates can be used). Such a combination of technologies made it possible to eliminate the main drawback of G12 antifreeze - not only to eliminate corrosion when it has already appeared, but also to perform a preventive action.

G12+, unlike G12 or G13, can be mixed with a G11 or G12 class liquid, but still such a “mix” is not recommended.

Cooling class G13 fluid has been produced since 2012 and is designed for automobile engines operating in extreme conditions. From a technological point of view, it has no differences from the G12, the only difference is that made with propylene glycol, which is less toxic, decomposes faster, which means causes less harm to the environment when it is disposed of and its price is much higher than the G12 antifreeze. Invented based on the requirements to improve environmental standards. G13 antifreeze is usually purple or pink, although it can actually be dyed in any color, since it is just a dye on which its characteristics do not depend, different manufacturers can produce coolants with different colors and shades.

The difference in the action of carboxylate and silicate antifreeze

G12 antifreeze compatibility

Is it possible to mix antifreezes of different classes and different colors of interest to quite a few inexperienced car owners who have purchased a used car and do not know which brand of coolant was filled in the expansion tank.