To improve thermophysical properties aqueous solution ethylene glycol (coolant, antifreeze, antifreeze liquid), the additive package used includes about a dozen substances designed to reduce the corrosive and oxidizing properties of the solution, its foaming, prevent the formation of scale and remove existing scale, as well as to stabilize the thermophysical characteristics of the coolant (Quality characteristics of ethylene glycol solutions must meet the requirements GOST 28084-89 "Anti-freezing coolants" and specifications developed on its basis). Most concentrated coolants are a solution consisting of 60%-65% ethylene glycol, 30%-35% water and 3%-4% active additives.
Such percentages ethylene glycol, water and inhibitors make it possible to obtain the best thermophysical characteristics of an aqueous solution as an effective coolant with a maximum subzero crystallization temperature of -70°C.
Aqueous solutions of ethylene glycol with a lower freezing point are produced using a lower concentration of ethylene glycol and mass fraction additives (inhibitors) remains practically unchanged. The dependence of the freezing temperature on the concentration of ethylene glycol is given below in table No. 1.
For various climatic operating modes and operating conditions of heating systems, a series of high-quality with the required crystallization temperature and stable thermophysical characteristics:
An aqueous solution of ethylene glycol is a coolant and antifreeze liquid for heating and cooling systems (package of anti-corrosion, anti-foam, anti-scale and stabilizing additives)
| Packaging, weight in kg | Concentration, % | Temperature of the beginning of crystallization (freezing), t°C | Sale / Price in rub./kg with VAT, when ordering from 1 ton | Sale / Price in rub./kg with VAT, when ordering more than 2 tons |
| Canister 20 kg, can 50 kg | 65% | minus -65°C | 80.00 rub./kg | |
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| Barrel 225 kg | 30% | minus -15°C | 49.00 RUR/kg | depending on batch size |
| Barrel 225 kg | 36% | minus -20°C | 55.00 RUR/kg | depending on batch size |
| Barrel 225 kg | 40% | minus -25°C | 57.00 RUR/kg | depending on batch size |
| Barrel 225 kg | 45% | minus -30°C | 60.00 rub./kg | depending on batch size |
| Barrel 230 kg | 50% | minus -35°C | 68.00 RUR/kg | depending on batch size |
| Barrel 230 kg | 54% | minus -40°C | 73.00 RUR/kg | depending on batch size |
| Barrel 230 kg | 65% | minus -65°C | RUB 77.00/kg | depending on batch size |
Properties, characteristics and application features
IN autonomous systems heating and industrial air conditioning as coolant An aqueous solution of ethylene glycol with additives for various purposes is widely used. The density of pure ethylene glycol is 1.112 g/cm3 at 20 °C, the freezing point is -13 °C. Aqueous solutions with ethylene glycol concentration from 30% to 70% have more low temperature freezing. Maximum subzero temperature freezing at –70 °C is achieved with an ethylene glycol concentration of 70%. When freezing, the ethylene glycol solution goes into an amorphous state, forming a viscous mass with an increase in volume within slightly larger limits than the increase in the volume of water when it freezes.
Concentrated solutions with 95% ethylene glycol content are also produced; they are diluted with water before pouring into the system. It is recommended to select the percentage of ethylene glycol based on the minimum temperature at which the coolant will be operated. Ready-made concentrated coolants with necessary value freezing temperatures are diluted with water before filling the system. For dilution, it is advisable to use distilled water; if it is not available, tap water with a hardness of up to 6 units. But it must be borne in mind that the use of unpurified water is undesirable due to possible incompatibility with the additive package.
Dilution of concentrated ethylene glycol by more than 50% leads to a noticeable deterioration in the consumer properties of the coolant.
Obtaining a high-quality aqueous solution of ethylene glycol with the required crystallization temperature and stable thermophysical characteristics is possible only under production conditions. The operating instructions for the equipment of most heating and industrial air conditioning systems place high demands on the thermophysical properties of solutions, and therefore it is recommended to use only ready-made aqueous solutions designed for the appropriate crystallization (freezing) temperature. Therefore the company CHIMTERMO produces a whole series of high qualityaqueous solutions of ethylene glycol.
The consumer must take into account that due to a number of significant differences in the thermophysical properties of water and ethylene glycol coolants, when using the latter, a number of problems arise. technical features, requiring special attention.
The viscosity of an ethylene glycol solution is 1.5–2.5 times greater than that of water; accordingly, the hydrodynamic resistance to the movement of liquid (aqueous solution) in pipes will be higher, which will require a more powerful circulation pump (approximately 8% in performance and 50% in pressure).
An aqueous solution of ethylene glycol has a greater coefficient of thermal expansion than water, so it is necessary to use a large expansion tank.
Coolant based on distilled aqueous solution ethylene glycol toxic and poisonous to the human body (belongs to the third class of hazard moderately hazardous substances) and is recommended for use exclusively in closed heating systems(with closed expansion tank).
The heat capacity of an ethylene glycol solution is approximately 15% less than that of water, which worsens heat transfer conditions and requires the installation of more powerful radiators.
It is not advisable to bring an aqueous solution of ethylene glycol to a boil, as this will lead to an irreversible change chemical composition and properties of the aqueous solution.
Table No. 1. Freezing temperature dependence aqueous ethylene glycol solution on its concentration
| Freezing temperature, °C | Ethylene glycol concentration, % | Freezing temperature, °C | |
| 5% | -2°C | 54% | -40°С |
| 11% | -4°C | 60% | -50°С |
| 15% | -6°C | 65% | -65°С |
| 21% | -9°С | 70% | -70°С |
| 25% | -11°C | 75% | -55°С |
| 30% | -15°С | 80% | -48°С |
| 36% | -20°С | 85% | -40°С |
| 40% | -25°С | 90% | -30°С |
| 45% | -30°С | 95% | -20°С |
| 50% | -35°С | 98% | -14°С |
ANTIFREEZES based on ethylene and propylene glycols and WATER. Freezing temperatures. Viscosity Densities. Heat capacities.
Antifreezes are liquids used to cool engines. internal combustion, electronic equipment, industrial heat exchangers and other installations operating at temperatures below 0°C. Basic requirements for antifreeze: low freezing point, high heat capacity and thermal conductivity, low viscosity at low temperatures, low foaming, high boiling and ignition temperatures. In addition, antifreezes should not cause destruction of the structural materials from which parts of cooling systems are made.
The most common antifreezes are based on aqueous solutions of ethylene glycol and propylene glycol (see below). However, such solutions cause significant corrosion of metals, so corrosion inhibitors are added to them - Na 2 HPO 4, Na 2 MoO 4, Na 2 B 4 O 7, KNO 3, dextrin, benzoate K, mercaptobenzothiazole and others. In some cases, aqueous solutions of salts are used as antifreeze; The most widely used solution is CaCl2. The disadvantages of such antifreezes are extremely high corrosive activity and crystallization of salts during the evaporation of water.
PROPERTIES OF ANTIFREEZE BASED ON AQUEOUS SOLUTIONS OF SALT(reference table for interest, such antifreezes are practically out of use)
ETHYLENE GLYCOL(1,2-ethanediol) HOCH2CH2OH, colorless, viscous, hygroscopic liquid, odorless, sweetish taste; melting point -12.7 °C, boiling point 197.6 °C. When ethylene glycol is dissolved in water, heat is released and volume decreases. Aqueous solutions freeze at low temperatures. Ethylene glycol is toxic if ingested and affects the central nervous system and kidneys; lethal dose 1.4 g/kg. The maximum permissible concentration in the air of the working area is 5 mg/m3.
PROPYLENE GLYCOLS(propanediols) C3H6 (OH)2 2 isomers are known: 1,2-P. CH3CHNOCH2OH (1,2-propanediol) and 1,3-P. CH2OHCH2CH2OH. Propylene glycols are colorless, viscous, hygroscopic liquids with a sweetish taste and odorless. For 1,2-P. melting point -60 °C, boiling point 189 °C. For 1.3-P. melting point -32°C, boiling point 213.5°C. 1,2-P. soluble in water, diethyl ether, monohydric alcohols, carboxylic acids, aldehydes, amines, acetone, ethylene glycol, limitedly soluble in benzene. When mixed with water or amines, the freezing point of the solutions sharply decreases. Toxicity of 1,2-P. (LD50 34.6 mg/kg, rats) is lower than that of ethylene glycol.
Safety levels for the average shelf life (biochemical activity) of products when 0.2% mass amount of coolant is added to them are given below.
The indicator is assessed on a five-point scale. A rating of five does not mean that you cannot be poisoned by the product in principle.
Freezing point of aqueous solutions of ethylene glycol and propylene glycol
Physical properties of an aqueous solution of ethylene glycol.
Antifreeze additives may slightly change the parameters, so be on the safe side.
| Volume fraction in the mixture % |
Minimum working temperature t, °C |
Temperature solution t, °C |
Density kg/m 3 |
Heat capacity KJ/kg*K |
Thermal conductivity W/m*K |
Dynamic viscosity sPuaz=mPa*s=10 -3 *N*s/m 2 |
Kinematic viscosity cSt=mm 2 /s=10 -6 m 2 /s |
| 20 | -10 | -10 | 1038 | 3,85 | 0,498 | 5,19 | 5,0 |
| 0 | 1036 | 3,87 | 0,500 | 3,11 | 3,0 | ||
| 20 | 1030 | 3,90 | 0,512 | 1,65 | 1,6 | ||
| 40 | 1022 | 3,93 | 0,521 | 1,02 | 1,0 | ||
| 60 | 1014 | 3,96 | 0,531 | 0,71 | 0,7 | ||
| 80 | 1006 | 3,99 | 0,540 | 0,523 | 0,52 | ||
| 100 | 997 | 4,02 | 0,550 | 0,409 | 0,41 | ||
| 34 | -20 | -20 | 1069 | 3,51 | 0,462 | 11,76 | 11,0 |
| 0 | 1063 | 3,56 | 0,466 | 4,89 | 4,6 | ||
| 20 | 1055 | 3,62 | 0,470 | 2,32 | 2,2 | ||
| 40 | 1044 | 3,68 | 0,473 | 1,57 | 1,5 | ||
| 60 | 1033 | 3,73 | 0,475 | 1,01 | 0,98 | ||
| 80 | 1022 | 3,78 | 0,478 | 0,695 | 0,68 | ||
| 100 | 1010 | 3,84 | 0,480 | 0,515 | 0,51 | ||
| 52 | -40 | -40 | 1108 | 3,04 | 0,416 | 110,8 | 100 |
| -20 | 1100 | 3,11 | 0,409 | 27,50 | 25 | ||
| 0 | 1092 | 3,19 | 0,405 | 10,37 | 9,5 | ||
| 20 | 1082 | 3,26 | 0,402 | 4,87 | 4,5 | ||
| 40 | 1069 | 3,34 | 0,398 | 2,57 | 2,4 | ||
| 60 | 1057 | 3,41 | 0,394 | 1,59 | 1,5 | ||
| 80 | 1045 | 3,49 | 0,390 | 1,05 | 1,0 | ||
| 100 | 1032 | 3,56 | 0,385 | 0,722 | 0,7 |
Physical properties of an aqueous solution of propylene glycol (1,2-Propylene glycol C3H6(OH)2)
Antifreeze additives may slightly change the parameters, so be on the safe side.
| Volume fraction in the mixture % |
Minimum working temperature t, °C |
Temperature solution t, °C |
Density kg/m 3 |
Heat capacity KJ/kg*K |
Thermal conductivity W/m*K |
Dynamic viscosity sPuaz=mPa*s=10 -3 *N*s/m 2 |
Kinematic viscosity cSt=mm 2 /s=10 -6 m 2 /s |
| 25 | -10 | -10 | 1032 | 3,93 | 0,466 | 10,22 | 9,9 |
| 0 | 1030 | 3,95 | 0,470 | 6,18 | 6,0 | ||
| 20 | 1024 | 3,98 | 0,478 | 2,86 | 2,8 | ||
| 40 | 1016 | 4,00 | 0,491 | 1,42 | 1,4 | ||
| 60 | 1003 | 4,03 | 0,505 | 0,903 | 0,9 | ||
| 80 | 986 | 4,05 | 0,519 | 0,671 | 0,68 | ||
| 100 | 979 | 4,08 | 0,533 | 0,509 | 0,52 | ||
| 38 | -20 | -20 | 1050 | 3,68 | 0,420 | 47,25 | 45 |
| 0 | 1045 | 3,72 | 0,425 | 12,54 | 12 | ||
| 20 | 1036 | 3,77 | 0,429 | 4,56 | 4,4 | ||
| 40 | 1025 | 3,82 | 0,433 | 2,26 | 2,2 | ||
| 60 | 1012 | 3,88 | 0,437 | 1,32 | 1,3 | ||
| 80 | 997 | 3,94 | 0,441 | 0,897 | 0,9 | ||
| 100 | 982 | 4,00 | 0,445 | 0,687 | 0,7 | ||
| 47 | -30 | -30 | 1066 | 3,45 | 0,397 | 160 | 150 |
| -20 | 1062 | 3,49 | 0,396 | 74,3 | 70 | ||
| -10 | 1058 | 3,52 | 0,395 | 31,74 | 30 | ||
| 0 | 1054 | 3,56 | 0,395 | 18,97 | 18 | ||
| 20 | 1044 | 3,62 | 0,394 | 6,264 | 6 | ||
| 40 | 1030 | 3,69 | 0,393 | 2,978 | 2,9 | ||
| 60 | 1015 | 3,76 | 0,392 | 1,624 | 1,6 | ||
| 80 | 999 | 3,82 | 0,391 | 1,10 | 1,1 | ||
| 100 | 984 | 3,89 | 0,390 | 0,807 | 0,82 |
Physical properties of water.
Water treatment (and sanitary) additives can slightly change the parameters, so be on the safe side.
| Temperature t,(°C) |
Pressure saturated vapors 10 3 *Pa |
Density kg/m 3 |
Specific volume (m3/kg)x10 - 5 |
Heat capacity KJ/kg*K |
Entropy KJ/kg*K |
Dynamic viscosity sPuaz=mPa*s=10 -3 *N*s/m 2 |
Kinematic viscosity cSt=mm 2 /s=10 -6 m 2 /s |
Coefficient volumetric expansion K -1 *10 -3 |
Enthalpy KJ/kg*K |
Prandtl number |
| 0 | 0,6 | 1000 | 100 | 4,217 | 0 | 1,78 | 1,792 | -0,07 | 0 | 13,67 |
| 5 | 0,9 | 1000 | 100 | 4,204 | 0,075 | 1,52 | 21,0 | |||
| 10 | 1,2 | 1000 | 100 | 4,193 | 0,150 | 1,31 | 1,304 | 0,088 | 41,9 | 9,47 |
| 15 | 1,7 | 999 | 100 | 4,186 | 0,223 | 1,14 | 62,9 | |||
| 20 | 2,3 | 998 | 100 | 4,182 | 0,296 | 1,00 | 1,004 | 0,207 | 83,8 | 7,01 |
| 25 | 3,2 | 997 | 100 | 4,181 | 0,367 | 0,890 | 104,8 | |||
| 30 | 4,3 | 996 | 100 | 4,179 | 0,438 | 0,798 | 0,801 | 0,303 | 125,7 | 5,43 |
| 35 | 5,6 | 994 | 101 | 4,178 | 0,505 | 0,719 | 146,7 | |||
| 40 | 7,7 | 991 | 101 | 4,179 | 0,581 | 0,653 | 0,658 | 0,385 | 167,6 | 4,34 |
| 45 | 9,6 | 990 | 101 | 4,181 | 0,637 | 0,596 | 188,6 | |||
| 50 | 12,5 | 988 | 101 | 4,182 | 0,707 | 0,547 | 0,553 | 0,457 | 209,6 | 3,56 |
| 55 | 15,7 | 986 | 101 | 4,183 | 0,767 | 0,504 | 230,5 | |||
| 60 | 20,0 | 980 | 102 | 4,185 | 0,832 | 0,467 | 0,474 | 0,523 | 251,5 | 2,99 |
| 65 | 25,0 | 979 | 102 | 4,188 | 0,893 | 0,434 | 272,4 | |||
| 70 | 31,3 | 978 | 102 | 4,190 | 0,966 | 0,404 | 0,413 | 0,585 | 293,4 | 2,56 |
| 75 | 38,6 | 975 | 103 | 4,194 | 1,016 | 0,378 | 314,3 | |||
| 80 | 47,5 | 971 | 103 | 4,197 | 1,076 | 0,355 | 0,365 | 0,643 | 335,3 | 2,23 |
| 85 | 57,8 | 969 | 103 | 4,203 | 1,134 | 0,334 | 356,2 | |||
| 90 | 70,0 | 962 | 104 | 4,205 | 1,192 | 0,314 | 0,326 | 0,698 | 377,2 | 1,96 |
| 95 | 84,5 | 962 | 104 | 4,213 | 1,250 | 0,297 | 398,1 | |||
| 100 | 101,33 | 962 | 104 | 4,216 | 1,307 | 0,281 | 0,295 | 0,752 | 419,1 | 1,75 |
| 105 | 121 | 955 | 105 | 4,226 | 1,382 | 0,267 | 440,2 | |||
| 110 | 143 | 951 | 105 | 4,233 | 1,418 | 0,253 | 461,3 | |||
| 115 | 169 | 947 | 106 | 4,240 | 1,473 | 0,241 | 482,5 | |||
| 120 | 199 | 943 | 106 | 4,240 | 1,527 | 0,230 | 0,249 | 0,860 | 503,7 | 1,45 |
| 125 | 228 | 939 | 106 | 4,254 | 1,565 | 0,221 | 524,3 | |||
| 130 | 270 | 935 | 107 | 4,270 | 1,635 | 0,212 | 546,3 | |||
| 135 | 313 | 931 | 107 | 4,280 | 1,687 | 0,204 | 567,7 | |||
| 140 | 361 | 926 | 108 | 4,290 | 1,739 | 0,196 | 0,215 | 0,975 | 588,7 | 1,25 |
| 145 | 416 | 922 | 108 | 4,300 | 1,790 | 0,190 | 610,0 | |||
| 150 | 477 | 918 | 109 | 4,310 | 1,842 | 0,185 | 631,8 | |||
| 155 | 543 | 912 | 110 | 4,335 | 1,892 | 0,180 | 653,8 | |||
| 160 | 618 | 907 | 110 | 4,350 | 1,942 | 0,174 | 0,189 | 1,098 | 674,5 | 1,09 |
| 165 | 701 | 902 | 111 | 4,364 | 1,992 | 0,169 | 697,3 | |||
| 170 | 792 | 897 | 111 | 4,380 | 2,041 | 0,163 | 718,1 | |||
| 175 | 890 | 893 | 112 | 4,389 | 2,090 | 0,158 | 739,8 | |||
| 180 | 1000 | 887 | 113 | 4,420 | 2,138 | 0,153 | 0,170 | 1,233 | 763,1 | 0,98 |
| 185 | 1120 | 882 | 113 | 4,444 | 2,187 | 0,149 | 785,3 | |||
| 190 | 1260 | 876 | 114 | 4,460 | 2,236 | 0,145 | 807,5 | |||
| 195 | 1400 | 870 | 115 | 4,404 | 2,282 | 0,141 | 829,9 | |||
| 200 | 1550 | 863 | 116 | 4,497 | 2,329 | 0,138 | 0,158 | 1,392 | 851,7 | 0,92 |
| 220 | 0,149 | 1,597 | 0,88 | |||||||
| 225 | 2550 | 834 | 120 | 4,648 | 2,569 | 0,121 | 966,8 | |||
| 240 | 0,142 | 1,862 | 0,87 | |||||||
| 250 | 3990 | 800 | 125 | 4,867 | 2,797 | 0,110 | 1087 | |||
| 260 | 0,137 | 2,21 | 0,87 | |||||||
| 275 | 5950 | 756 | 132 | 5,202 | 3,022 | 0,0972 | 1211 | |||
| 300 | 8600 | 714 | 140 | 5,769 | 3,256 | 0,0897 | 1345 | |||
| 325 | 12130 | 654 | 153 | 6,861 | 3,501 | 0,0790 | 1494 | |||
| 350 | 16540 | 575 | 174 | 10,10 | 3,781 | 0,0648 | 1672 | |||
| 360 | 18680 | 526 | 190 | 14,60 | 3,921 | 0,0582 | 1764 |
No less important than the brand of fuel for the engine. Knowledge of the composition and types will help drivers choose high-quality and, most importantly, suitable coolant for the car. What types are there, how the composition of antifreeze and antifreeze differs - readers will learn all this after studying this material.
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” belongs to it. This coolant contains inorganic acids, borates, silicates, phosphates, nitrates and nitrites. Silicates are the main additive in inorganic coolant. This antifreeze is not suitable for modern cars, as it has many disadvantages. It is made on the basis of ethylene glycol.
Additives are deposited on the inner surface of pipelines, their main task is to provide protection against corrosion and normal conductivity. Antifreeze copes with the first task “excellently”, and with the second - exactly the opposite. Due to low thermal conductivity, heat exchange 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 - silicate antifreeze needs to be changed 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 disadvantages than the silicate version. Organic additives cover only those areas where corrosion occurs, so there is virtually no loss of heat transfer. 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 driver's task is to choose suitable look for your car. If this is an old domestic car, then antifreeze will not make it worse, and it costs significantly less than organic antifreeze. In other cases, you need to purchase carboxylate coolant. As for replacing antifreeze, it is required only after 200 thousand kilometers. Such a long life was also achieved by adding organic additives.
Antifreeze classification
Today there are three classes of antifreeze:
- Class G11. Has green or blue color. This class includes the cheapest liquids available on the automotive markets. The composition of G11 antifreeze 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 short - about 30 thousand kilometers.
- Class G12. Most often it is red or pink antifreeze. More high level quality. This liquid lasts much longer and has more useful properties, but the price for G12 is higher than for G11. G12 antifreeze already contains organic additives and ethylene glycol.
- Class G13(formerly G12+). Has orange or yellow. This class includes environmentally friendly coolants. They decompose quickly and do not harm environment. This result became available after adding propylene glycol to G12 antifreeze, while carboxylases remained as additives. Any ethylene glycol-based antifreeze will be more toxic than its propylene glycol-based counterpart. The only negative about the G13 is high price. The environmentally friendly G13 is most common in European countries.
Popular brands of antifreeze
We have figured out the classification, now we can go through famous brands which are preferred by drivers throughout the CIS. These include:
- Felix.
- Alaska.
- Nord.
- Syntek.
This is the most optimal options in terms of price/quality ratio. So, let's start with “Felix” - this antifreeze is intended for all trucks and passenger cars. Able to function normally in difficult conditions climatic conditions. Part antifreeze Felix includes special patented additives that extend the life of the cooling system pipelines and 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 quality liquids, which belong to Antifreeze (G11 based on inorganic additives), then this is Alaska. The emphasis in these products is on combating the cold. For example, a certain composition of Alaska antifreeze can withstand temperatures down to -65°C. There are also options for warm regions, where in winter the thermometer needle does not fall below 25°C. Of course, types of antifreeze marked G11 have their drawbacks.
Composition and properties of antifreeze Alaska
Another a good option– these are NORD antifreezes. The company supplies to automobile market all types of coolant are from G11 to G13, so there is no point in describing the composition of NORD antifreeze.
And the last option we will consider is automotive antifreeze Sintec. The company mainly produces G12 class liquid. Antifreeze is great for everyone modern engines. Many professional repairmen recommend using antifreeze from this company to those drivers who drive cars with aluminum engine. The composition of Sintek 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. Sintek also reliably protects the cooling system from corrosion.
Composition and properties of syntek antifreeze
Today, the antifreeze market for car radiators is filled with products based on ethylene glycol. This substance has a number positive qualities during operation. From the right choice The use of the cooling system depends on its durability, as well as engine performance.
Ethylene glycol-based antifreeze has a low freezing point, which depends on the concentration of the substance. The liquid inside the cooling system begins to crystallize in the range from 0 to -70ºС. When choosing high-quality antifreeze, it is necessary to take into account the operating conditions of the machine. In summer, it should cool the engine as efficiently as possible. In winter, the liquid should not freeze even in severe frosts.
Types of antifreeze
Today there are two main types of antifreeze - carbosilicate and silicate substances. The second type is used in older cars. The most well-known representative This class of products is antifreeze. Silicate antifreezes have a number of disadvantages, so they are not used for foreign cars.
Silicate-free antifreeze based on ethylene glycol is preferable for foreign new cars. During vehicle operation, the additives that make up the product settle exclusively in areas where corrosion forms. This became possible thanks to the inclusion of organic components in the product. In this case, the engine is completely cooled.
Silicate varieties made from ethylene glycol cover the entire inner surface tubes with inorganic components. They effectively prevent the formation of corrosion, but at the same time reduce the cooling capacity of the system.
Antifreeze composition
Ethylene glycol-based antifreezes have a specific composition. Their main characteristics depend on this. IN pure form ethylene glycol looks like an oily substance. Its freezing point is -13ºС, and its boiling point is +197ºС. This substance is quite dense. Ethylene glycol is a strong food poison. This substance is toxic, especially after its resource has been exhausted. Waste antifreezes based on ethylene glycol, the composition of which was contaminated during operation with heavy metals, require proper disposal.
When mixed with it, it can decrease significantly (up to -70ºС with a ratio of water and ethylene glycol of 1:2). Organic and inorganic components can be used as additives. The first option is preferable. Today there are 4 types: carboxylate, traditional, organic and hybrid. Due to the difference in the components that make up antifreeze, you cannot mix different brands these funds. Otherwise, they will conflict with each other, reducing the effectiveness of the substance.
Antifreeze color
Initially, ethylene glycol-based antifreeze, the color of which can be seen in production, looks like a transparent substance. It only has a specific smell. Regardless of the brand, antifreeze has no color. Dyes are added to identify its quality. Among drivers and auto mechanics, there is an accepted classification of the quality of a product depending on its color. There are 3 groups of antifreeze.
- Class G11 includes blue and green products. These are the cheapest consumables. They contain ethylene glycol and silicate additives. The service life of such antifreeze is about 30 thousand km.
- Class G12 includes red and pink substances. They are characterized by more high quality. They contain ethylene glycol and organic additives. The service life of such equipment can reach 150-200 thousand km. However, their cost is much higher.
- There is also a third class - G13. Its composition, in addition to the components listed in the previous section, includes propylene glycol. The color of such products is most often characterized by orange and yellow shades.
Labeling system
Each ethylene glycol based antifreeze for aluminum radiators, as well as loaded cooling systems, contains dyes. They have no effect on specifications substances. The choice of one color or another depends on the whim of the manufacturer. There is no generally accepted standard for labeling or adding colorants.
The markings presented above, which are most often taken into account by drivers and auto mechanics, were previously used in the production of German-made VW coolant antifreezes. These products are very popular. However, even he himself has already changed his specifications. Today this famous manufacturer produces 3 main classes of organic-based antifreeze. Their markings have the prefixes G12++, G12+++ and G13. Therefore, before purchasing a product for cooling system it is more correct to pay attention to the recommendations of the vehicle manufacturer, as well as the composition of the consumables. There is no single label for all antifreezes.
Basic properties of antifreeze
During their operation, antifreezes exhibit a whole range of qualities. They are regulated by the standards and approvals of car manufacturers. It should be noted that ethylene glycol is a toxic substance. As its resource is exhausted, this indicator increases. There are rules on how to dispose of ethylene glycol-based antifreeze waste. They are credited with various negative properties. Therefore, if you need to contact special organization, which will dispose of it correctly.
It is also important to consider the foaming properties of antifreeze. For funds domestic production this figure is 30 cm³, and for imported ones - 150 cm³. The wettability of antifreeze is 2 times greater than that of water. Therefore, they are able to seep even into very thin cracks. This explains their ability to flow out even in the presence of microcracks.
Review of popular brands
In our country they use various brands ethylene glycol based antifreeze. The most popular include “Felix”, “Alaska”, “Sintek”, Long Life, Nord. They are characterized by an optimal price-quality ratio.
The presented antifreezes are intended for harsh conditions our climate. Also, the developed line of products allows the driver to select the required product for the engine of his car. The presented products effectively resist the formation of corrosion and also provide good cooling properties of the radiator.
Products popular in our country today effectively protect engine systems from the formation of deposits, especially in the water pump, engine compartment and supply channels.
Today I finally decided to write an article about the composition of antifreezes that are used in automotive industry. There are many myths and legends about the components, but personally I have never found any normal sane information that can be read to the common man, without chemical education and understand what kind of miracle solution this is. As usual, I will try to convey to you in ordinary “human” words...
First, a little definition
Antifreeze (Antifreeze - non-freezing) is a liquid for a car, which is used in the engine cooling system. It prevents the engine from boiling when high temperatures, and also does not freeze at negative temperatures. If this liquid is diluted correctly, it can hold up to – 60 – 70 degrees Celsius.
If you dig into history, many cars used to use ordinary water for cooling, but it was extremely inconvenient - the water boiled already at 100 degrees Celsius and evaporated, and it also froze at zero degrees, which led to serious damage.
General composition of antifreeze
Whatever one may say, all antifreezes, be it 80%, consist of almost the same thing:
- Ethylene glycol (monoethylene glycol, ethanediol, etc.) - it's simple dihydric alcohol, oily consistency, practically odorless, slightly viscous, if you measure the density, it is 1.112-1.113 g/cm3 (if measured at 20 degrees Celsius). The boiling point is 196 ° C, but it freezes at - 12, - 13 ° C (therefore, it must be diluted with water). When heated, it expands greatly, so about 10% less is poured into the system when it is cold.
- Water . It is MANDATORY necessary, otherwise pure “glycols” will freeze at -13 °C. Distilled water must be used so as not to cause scale on the walls of pipes and radiators.
- Additives . These are mainly anti-corrosion - they are divided into four types: - lobrid, carbonoxylate, hybrid and traditional.
This is the main composition of antifreeze; if everything is clear with the first and second points, then the third point (additives) needs additional explanation.
Antifreeze additives
As I have already indicated their 4 main types, I will try to talk about each separately:
Traditional – have been used as a corrosion inhibitor for a very long time, literally from the moment of their foundation, their compositions contain silicates, phosphates, borates, nitrites, amines, etc., it should be noted that all substances are of inorganic origin. Such antifreezes are now becoming a thing of the past, because they have two big drawbacks:
- is not long term service (about 2 years) after this period, silicates contained in the composition settle on the walls of tubes and radiators - impairing cooling,
- inability to withstand high positive temperatures; already at 110 ° C, they boil.
Traditional ones include our antifreeze, blue.
Carbonoxylate – used in red antifreeze, made on the basis of organic compounds, namely carboxylic acids. It does not form protective films on pipes and radiators, but fights against corrosion areas, forming a thin film (about 0.1 microns) on them, which does not interfere with cooling.
On his this moment The longest service life is 5 years.
Hybrid – such additives are contained in green antifreezes. Consists of both organic and non-organic compounds - that is, a “hybrid”. The service life is not as long as that of carbon additives, only 3 years.
Lobridaceae – used in purple antifreeze. The most advanced at the moment, their composition is mineral protective substances + organic compounds. The principle of their operation can be described as follows: mineral substances form a very thin protective film, which does not interfere with cooling, and organic compounds are consumed only in cases where corrosion occurs. As the creators assure, antifreezes with such additives have very long term service, sometimes equal to the entire service life of the vehicle.
As you can see, there are big differences in additives, each tailored to its own needs. But wait, you tell me - why are additives needed at all, since it seems like alcohols do not cause corrosion or is it all water’s fault?
About corrosion
Again, many of us are “stepping on our own rake,” thinking that if ethylene glycol is alcohol, then it will not oxidize and react with the walls of pipes and radiators. But that's not true! When mixed with water, it becomes a highly corrosive compound! If it is not “isolated” - with additives, then it will corrode the walls of metal pipes and radiators, rust will begin to appear, and so quickly that leaks are possible within a few months.
To prevent such a process, additives are needed, this is a MUST! That is, they seem to pacify the mixture of ethylene glycol and water.
Antifreeze temperature and composition
Antifreeze should cope equally well with high and low temperatures. Let’s just say that if you pour pure ethylene glycol, it will maintain a positive temperature of 196 °C, that is, almost any engine will be perfectly cooled, because the operating range is often below 95 °C (of course, there are high-temperature engines, but they are not so common).
But pure ethylene glycol will hold a low temperature disgustingly; even at -13 degrees it will simply freeze inside the engine (which will cause serious damage).
A few words about cavitation
The composition of the coolant must take into account “cavitation” inside the cooling system. The thing is that when the fuel detonates, high-frequency vibrations transfer to the walls of the cylinder head, which is why the antifreeze “boils.” Small bubbles constantly form and burst - this is cavitation. Such bubbles negatively affect the composition of the liquid, namely, they reduce the protection of additives, so a source of corrosion can often occur. Therefore, you need to choose the right antifreezes, for example, those based on carboxylic acid and lobrides, which resist cavitation many times better than “traditional” and hybrid fluids.
Foam formation
It is worth noting that when developing coolants, such compositions were selected so that no foam would appear at all - after all, foam is “almost” “airing” of the cooling system tubes, which can lead to disastrous results - simply overheating. Therefore, almost none of the compositions (with various additives) do not foam. Which is already good! It’s also worth noting that when diluting, mix it with water, it foams beautifully.
Protection of rubber and plastic connections
The system is not all metal; there are many rubber and plastic hoses and connections. Antifreeze should not corrode them, if it practically does not react to plastic, then rubber - it should protect against cracking and premature “drying out”. The red carbon version does this perfectly. And the rest are kept at a very high level.
About color
This is a controversial issue, there are many disputes and legends about it that supposedly all reasoning is deceptive. What, for example, in green antifreeze You can pour red and nothing will happen! And the color is banal marketing ploy! As I already wrote above, antifreezes are specially tinted so that you know what additive is present in it, carbonic acid, hybrid, ordinary traditional or some other.
Also, many do not want to delve into such information - not all cars have a similar cooling system, I mean the metal from which it is made, some have brass or copper in their structure, others have aluminum. For example, carbonic acid additives (red color) perfectly protect copper and brass, but they corrode aluminum. But hybrid additives ( green color) protect aluminum well, but copper and brass not so well.
