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Encyclopedia

ABRASIVE WEAR

Mechanical wear (wear) as a result of the impact of solid particles in a free or fixed state as a result of mechanochemical processes of formation and destruction of secondary structures.

ABSORPTION

(from lat. absorbtio absorption) - the phenomenon and process of mass transfer, which consists (in contrast to adsorption) in the volumetric absorption of the components of the gas phase by the absorbent. In engineering and chemical technology, absorption (absorption, dissolution) of gases by liquids is most common. But the processes of absorption of gases and liquids by crystalline and amorphous bodies are also known (for example, the absorption of hydrogen by metals, the absorption of low-molecular liquids and gases by zeolites, the absorption of petroleum products by rubber products, etc.). Often in the process of absorption, not only an increase in the mass of the absorbent material occurs, but also a significant increase in its volume (swelling), as well as a change in its physical characteristics - up to the state of aggregation. In practice, absorption is most often used to separate mixtures consisting of substances having different absorption capacities with suitable absorbents. In this case, the target products can be both absorbed and non-absorbed components of mixtures. Typically, in the case of physical absorption, the absorbed substances can be re-extracted from the absorbent by heating it, diluting it with a non-absorbent liquid, or other suitable means. Regeneration of chemically absorbed substances is also sometimes possible. It may be based on chemical or thermal decomposition of the products of chemical absorption with the release of all or some of the absorbed substances. But in many cases, the recovery of chemically absorbed substances and chemical absorbents is not possible or technologically/economically impractical.

ADHESION

(from Latin adhaesio - sticking) the adhesion of dissimilar condensed phases brought into contact, due to intermolecular interaction or chemical bonding. During friction, an important role is played by the process of adhesive interaction of lubricant molecules with rubbing metal surfaces. Adhesion significantly affects the nature of the friction of the contacting surfaces: for example, when interacting surfaces with low adhesion, friction is minimal. An example is polytetrafluoroethylene (Teflon), which, due to its low adhesion value, in combination with most materials, has a low coefficient of friction. Some substances with a layered crystal lattice (graphite, molybdenum disulfide), characterized by both low values ​​of adhesion and cohesion, are used as solid lubricants. The most well-known adhesive effects are capillarity, wettability/nonwetting, surface tension, liquid meniscus in a narrow capillary, static friction of two absolutely smooth surfaces. The criterion for adhesion in some cases may be the time of detachment of a layer of material of a certain size from another material in a laminar fluid flow.

ADSORPTION

(from lat. ad on, at, with + sorbere to absorb, absorb)

1. The phenomenon of concentration of matter from the volume of phases on the interface.

2. Mass transfer process by adsorption.

The absorbed substance, which is still in the bulk of the phase, is called the adsorbate, and the absorbed substance is called the adsorbate. In a narrower sense, adsorption is often understood as the absorption of an impurity from a gas or liquid by a solid substance (in the case of gas and liquid) or liquid (in the case of gas) - an adsorbent. In this case, as in the general case of adsorption, the impurity is concentrated at the adsorbent-liquid or adsorbent-gas interface. The process, the reverse of adsorption, that is, the transfer of a substance from the interface to the volume of the phase, is called desorption. If the rates of adsorption and desorption are equal, then one speaks of the establishment of adsorption equilibrium. In a state of equilibrium, the number of adsorbed molecules remains constant for an arbitrarily long time, if the external conditions (pressure, temperature, and composition of the system) remain unchanged.

ANTI-CORROSION PROTECTION

Application of layers of protective coatings based on organic and inorganic materials, in particular, paintwork materials, metals and alloys, to the surface of protected structures. In anti-corrosion protection, the adhesion of the coating material to the surface is the most important parameter that affects the durability of the coating. Adhesion - adhesion of the paintwork material to the surface to be painted, one of the main characteristics of industrial coatings. The adhesion of paints and varnishes can be mechanical, chemical or electromagnetic in nature and is measured by the force of separation of the paintwork per unit area of ​​the substrate. Good adhesion of the paintwork material to the surface to be painted can only be ensured by thoroughly cleaning the surface from dirt, grease, rust and other contaminants. Also, to ensure adhesion, it is necessary to achieve a given coating thickness, for which wet film thickness gauges are used. Criteria have been adopted and approved for the assessment of adhesion/cohesion.

AROMATIC HYDROCARBONS (ARENES)

Aromatic compounds (arenes) are cyclic organic compounds that have an aromatic system in their composition. A class of carbocyclic compounds containing a special cyclic group of six carbon atoms (benzene nucleus). The main distinguishing properties are the increased stability of the aromatic system and, despite unsaturation, a tendency to substitution reactions, rather than addition. Benzenoid aromatic hydrocarbons (arenes) are widespread and of great practical importance. In addition to benzene rings, arenas often contain various other hydrocarbon groups (aliphatic, naphthenic, polycyclic). The main sources of aromatic hydrocarbons are coal tar, oil and oil products. Synthetic methods of obtaining are of great importance. The most important arenes are: benzene C6H6 and its homologues (toluene C6H5CH3, xylenes C6H4(CH3)2, durol, mesitylene, ethylbenzene), cumene, naphthalene C10H8, anthracene C14H10 and their derivatives. Aromatic hydrocarbons are the feedstock for the industrial production of ketones, aldehydes, and aromatic acids, as well as many other substances.

ASPHALTEN

The most high-molecular components of oil. Solid brittle substances of black or brown color; soften in an inert atmosphere at 200–300°C with a transition to a plastic state; density about 1.1 g/cm3; number average molecular weight 1000-5000, polydispersity index 1.2-3.5. There is a genetic link between asphaltenes, petroleum resins and petroleum oils. When moving from oils to resins and asphaltenes, the number of condensed cycles, heteroatoms, and molecular weight increase, and the H/C ratio decreases. Thermal polycondensation of asphaltenes leads first to the formation of carbenes, then carboids (see Petroleum bitumen) and coke. During thermopolycondensation of resins or visbreaking of tars, dehydrogenation, dehydrocyclization, and dealkylation occur, resulting in the formation of secondary asphaltenes characterized by a high degree of aromaticity. Under conditions of mild hydrogenolysis, asphaltenes are converted into resinous and oily substances. Asphaltenes are a residual product of the extraction of heavy oil residues with hexane (Golde's "hot method"). In industry, such extraction is carried out with liquid propane or butane (see Deasphalting). The presence of V and Ni in asphaltenes, which are poisons of oil refining catalysts, significantly limits the possibility of obtaining motor fuels based on oil residues. Asphaltenes are vulcanizing agents, inhibitors of corrosion and radical reactions, fillers for composite polymer materials, raw materials for the production of V and Ni. In the composition of tars and bitumens, they are used to create road surfaces, manufacture waterproofing materials, roofing products, etc.

BASE OIL

Base oils are raw materials and the main component of commercial oils. As base oils in the production of lubricants, mineral (petroleum), synthetic, HC-synthetic oils, as well as their mixtures, are used. For special purposes, vegetable oils are also used. Base oils become marketable after mixing with additive packages that improve their properties.

The most important characteristic of the base oil is the viscosity index (abbreviated as VI, from the English Viscosity Index), which characterizes the ability of the oil to thin under the influence of temperature. The higher the viscosity index, the better the quality of the oil.

API BASE OIL GRADES

GROUP 1 - mineral, contains less than 90% saturated hydrocarbons and 0.03% sulfur, has a viscosity index from 80 to 120 (usually <90)

GROUP 2 - mineral, contains not less than 90% saturated hydrocarbons and less than 0.03% sulfur, has a viscosity index from 80 to 120 (usually 95)

GROUP 3 - contains at least 90% saturated hydrocarbons and less than 0.03% sulfur, has a viscosity index of more than 120 (usually 140-150) (HC-synthetic, cracking, hydrosynthetic, technosynthesis, Syntetishblend, MS-synthesis)

GROUP 4 - synthetic polyalphaolefins (viscosity index 130)

GROUP 5 - synthetic base oils of other types, not included in groups 1-4 (complex alcohols and esters).

WHITE OIL

Highly refined oil base for use in the pharmaceutical and cosmetic industries, as well as for lubricating machines in food processing. Colorless, non-fluorescent petroleum oils produced by deep catalytic hydrogenation of petroleum fractions or deep purification of oil distillates with fuming sulfuric acid or sulfuric anhydride and bleaching earth. White oils are obtained by deep refining petroleum oils, usually with sulfuric acid. Before treating oils with acid, they can be pre-cleaned with some selective solvent. White oils are divided into 2 groups:

  • technical white oils (used for the production of cosmetic creams, perfume oils, insecticides, in the textile industry, etc.);
  • medical white oils (used in the synthesis of drugs and as a lubricating oil in the food industry).

White oils are pure naphthenic-paraffinic hydrocarbons without impurities of aromatic compounds and resins. These oils have a weaker effect on rubber, and are chemically and biologically more inert than representatives of other petroleum oils, however, oxidation resistance, as well as lubricating properties, are worse for white oils. The kinematic viscosity of technical white oils at 50 ° C is 28-36 cSt, medical - 16-24 cSt.

BIOLOGICAL DEGRADABILITY

The ability of a substance to be broken down by microorganisms into non-toxic, water-soluble compounds.

BIOCONTAINING WATER-MIXABLE PRODUCTS

The defeat of the water-miscible product by microorganisms - bacteria, fungi, yeast.

VACUUM DISTILLATION

The process of fractional distillation of the residue from atmospheric distillation (fuel oil) in a vacuum column under reduced pressure.

OIL FOAMING

The property of oil to form foam under the action of rotating parts of mechanisms.

ENTRANCE CONTROL

Checking a number of indicators of the quality of an oil product for compliance with regulatory documentation or documents of the sender when it arrives at the warehouse or consumer.

VISCOSITY OF PETROLEUM PRODUCTS

Viscosity is understood as the property of a liquid to resist the movement of its particles during movement or the resistance force of the displacement of one layer of the liquid relative to another. This property is also called the internal friction of a liquid or gas. The nature of this friction is associated with overcoming the forces of intermolecular interaction of a liquid or gas. Viscosity characterizes the fluidity or mobility of an oil product or gas, pumpability through pipelines, and is the main characteristic of paraffin oil, dark oil products (fuel oil, motor fuel) and oils. It is customary to characterize the viscosity of oil and oil products by several types of measurements: relative; dynamic, kinematic. Relative (conditional) viscosity is the ratio of the outflow time of 200 ml of oil or oil product at a given temperature through the calibrated opening of the viscometer to the outflow time of the same amount of distilled water at a temperature of 20 °C. This ratio is expressed in degrees of relative viscosity (°VU). For example, VU50 =4° means a viscosity equal to 4°VU at a temperature of 50°C. In the international SI system, viscosity is distinguished between dynamic and kinematic. Dynamic viscosity is a measure of internal friction, equal to the ratio of tangential stress to the shear rate gradient during laminar fluid movement, denoted by the symbol q and expressed in Pa or n s / m2 or n s / cm2, or this means that with a velocity gradient m (cm ) a friction force equal to 1 n acts on 1 m of the layer. Kinematic viscosity (v) is the ratio of dynamic viscosity to the density of an oil product, is the reciprocal of dynamic viscosity, denoted by the symbol v and is expressed in stokes: 1 cm2 / s = 1 st = 10-4 m2 / s. The kinematic viscosity is converted into conditional viscosity according to the empirical Ubbeloid formula v \u003d 0.0731 VU - 0.0631 / VU. The viscosity of oil varies widely and depends on reservoir pressure, temperature and gas dissolved in oil. The viscosity of petroleum products depends on temperature. To a greater extent, temperature affects the viscosity of dark petroleum products and oils, rather than light petroleum products. In hydraulic calculations, the viscosity of petroleum products is taken according to a nomogram or according to quality certificates.

VISCOSITY OF PUMPING (PUMPLABILITY)

A measure of the ability of the oil to flow and build up the necessary pressure in the lubrication system in the early stages of a cold engine.

HYGROSCOPICITY

The ability of a petroleum product to absorb water vapor or water from the environment. The higher the temperature and relative humidity of the environment, the more water is dissolved in the oil. Petroleum products containing paraffinic, naphthenic and olefinic hydrocarbons dissolve water less than petroleum products containing aromatic hydrocarbons.

HYDROCRACKING

The process of obtaining base oils with a high viscosity index, antioxidant resistance and shear resistance. During the processing process, a number of chemical reactions occur simultaneously or sequentially, as a result of which the molecular structure of the oil is significantly improved, resistance to mechanical, thermal and chemical influences is enhanced. Hydrocracking is one of the most promising methods for improving the properties of oils.

HYDROTREATMENT

General name for the refining process in the production of fuels and petroleum feedstocks. It is carried out at elevated temperature in the presence of pressurized hydrogen and a catalyst. This mild oil refining, sometimes also referred to as hydrofinishing, is used to improve the color and odor of fuels and base oils.

DEMULSIBILITY

A measure of the ability of a lubricating oil to separate from water.

DYNAMIC VISCOSITY

A measure of internal friction during the flow of lubricating oil (for example, flow through pipes or slots).

DISPERSION

Fine grinding of solids and liquids in various media, leading to the formation of dispersed systems.

THICKENERS

Thickeners are usually metal soaps (soap thickening), but other organic and inorganic thickening agents (non-soap thickening, eg, silica, bentonite, urea, PTFE, etc.) may be used.

ASH SULFATE

An indicator characterizing the presence of ash additives (sulfonates, alkyl phenolates, alkyl salicylates and phosphonates of calcium, barium or magnesium in various combinations with each other, metal-containing) in motor oils. Expressed in % wt.

WEAR

Caused by friction and direct contact between opposing surfaces after the lubricating film breaks down. Change in the size, shape or state of the surface of a sample or product due to the destruction of the surface layer, in particular during friction. There are four main wear mechanisms: abrasive wear and fatigue failure of surface layers (purely mechanical processes), as well as wear under the influence of adhesion and as a result of tribochemical reactions on the surface of bodies (oxidative wear). More often, the wear process is determined by several mechanisms.

CORROSION INHIBITORS

Lubricant additives that reduce oxidation and thus aging, red rust and corrosion.

VISCOSITY INDEX

Relative value showing the degree of change in viscosity depending on temperature. Liquids with a high viscosity index change less in viscosity with temperature changes than liquids with a low viscosity index.

ACID NUMBER

The indicator characterizing the presence of hydrocarbon oxidation products in the oil product is expressed as the number of milligrams of KOH required to neutralize 1 g of the oil product.

ACIDITY

The indicator characterizing the presence or absence of hydrocarbon oxidation products in the oil product is expressed as the number of milligrams of KOH that is required to neutralize 100 ml of the oil product.

COAGULATION

Combining small dispersed particles into larger aggregates.

COLLOID

Dispersed systems intermediate between true solutions and coarse systems - suspensions, in which discrete particles, drops or bubbles of the dispersed phase, having a size in at least one of the measurements from 1 to 100 nm, are distributed in a dispersion medium, usually continuous, differing from the first in composition or aggregate state. In freely dispersed colloidal systems (fumes, sols), particles do not precipitate.

COMPOUNDING

Mixing several components in a certain ratio to obtain an oil product of a given quality.

CONSISTENCY

Мера состояния (твердости) консистентных смазок. Она измеряется по пенетрации инструмента в нерабочую и рабочую смазку и количественно выражается в соответствии с рекомендациями NLGI (National Lubricating Grease Institute = Национальный Институт Консистентных Смазок). Для упрощения выражения консистенции консистентных смазок, весь диапазон консистенции в соответствии с пенетрацией в рабочую смазку делится на девять классов. Согласно классификации NLGI смазки делят на классы в зависимости от уровня пенетрации – чем больше численное значение пенетрации, тем мягче смазка. Классификация NLGI пластичных смазок по консистенции приведена в таблице (соответствует сортам по DIN 51818. DIN – Институт стандартов Германии). Существует девять категорий – от 000 до 6:

  • Categories 000 and 00 are semi-fluid lubricants used as an alternative to oils in machinery and centralized lubrication systems with small cross-sections of supply channels (for example, in modern trucks);
  • 0 and 1 - categories for use in the main centralized lubrication systems (for example, industrial equipment, trucks);
  • Categories 2 and 3 are mainly used for bearing lubrication;
  • Grades 4 and 6 are exceptionally thick greases and are rarely used except in special cases of "grease blocks".

Note. Greases used on a passenger car, as a rule, belong to the second class.

CLASS NGLIPENETRATION
unit = 0.1
LUBRICANT CONSISTENCYAPPLICATION AREA
000445-475very liquidlosed gears
00400-430liquidlosed gears
0355-385semi-liquidentralized lubrication systems
one310-340very softentralized lubrication systems
2265-295softball/roll bearings
3220-250quite softhigh speed bearings
four175-205semi-solidhigh speed bearings
5130-160hardopen gears
685-115very hardopen gears
CORROSIVE AGGRESSIVENESS

The property of petroleum products to cause the destruction of metal products. The corrosive aggressiveness of oils, as well as individual groups of hydrocarbons, is determined mainly by their oxidizability and the nature of the products formed. Since aromatic hydrocarbons have an inhibitory effect on the oxidation of naphthenic hydrocarbons, thereby reducing their corrosiveness, they must be present in the oil in a certain concentration. The intensity of corrosion of metals under the influence of moisture is largely determined by the moisture resistance of lubricants, which depends primarily on the solubility and emulsifying ability of the individual components of the lubricant. The mechanical strength of lubricants is also of significant importance, especially under the conditions of the mechanical action of water (atmospheric precipitation, splashing with water). Humid air also increases the corrosiveness of oils and greases, especially when containing sulfur compounds. In this case, we can talk not only about natural sulfur compounds, but also about those additives that are introduced into lubricants in order to improve their antioxidant, antiwear and other properties. Among greases derived from fatty acid soaps, calcium and aluminum greases are the most resistant to moisture, sodium greases are the easiest to wash out. The close relationship between the possible manifestations of the corrosiveness of lubricants and their chemical stability indicates the need to take into account the stability index as a potential corrosion factor. The accepted method for evaluating the chemical stability of lubricants is the oxidation of their samples in a gauge vessel at high pressure and high temperature. The criterion for the stability of the lubricant is the amount of absorbed oxygen and released acids.

COEFFICIENT OF FRICTION

The ratio of the force of friction between two surfaces sliding over one another to the force perpendicular to those surfaces. The coefficient of friction is the main characteristic of friction as a phenomenon. It is determined by the type and condition of the surfaces of rubbing bodies. The coefficient of friction is the coefficient of proportionality that relates the friction force () and the force of normal pressure (N) of the body on the support. Most often, the coefficient of friction is denoted by the letter µ. This coefficient of friction does not depend on the areas of contact surfaces. In this case, we are talking about the coefficient of sliding friction, which depends on the combined properties of the rubbing surfaces and is a dimensionless quantity. The coefficient of friction depends on: the quality of surface treatment, rubbing bodies, the presence of dirt on them, the speed of movement of bodies relative to each other, etc. The coefficient of friction is determined empirically (experimentally). The coefficient of friction, which corresponds to the maximum static friction force, is in most cases greater than the coefficient of motion friction. For a larger number of pairs of materials, the value of the friction coefficient is not greater than unity and lies within 0.1≤µ≥0.5.

CRACKING

(eng. cracking, splitting) - high-temperature processing of oil and its fractions in order to obtain, as a rule, products of a lower molecular weight - motor fuel, lubricating oils, etc. Secondary (destructive) process of processing oil or its fractions, carried out to increase output of light products and improve their quality.

CRYSTAL CELL

An ordered three-dimensional structure of a solid that has the correct repeatability of the arrangement of particles (atoms, molecules, or ions).

LACQUER DEPOSITS

Also called lacquer coating - a thin insoluble film on the moving parts of the engine from the oxidation of the lubricant (or fuel) at high temperatures.

VOLATILITY

A measure, usually dependent on temperature, that characterizes the rate at which a liquid is converted to vapor. Ideally, combustible materials should have high volatility, while lubricants.

MINERAL OILS

The base of mineral oils is made from crude oil, which undergoes a variety of complex refining processes. They are relatively inexpensive and represent an average level of quality. They are most often used for both automotive and industrial needs.

FRICTION MODIFIERS

Oil-soluble compounds adsorbed on the metal surface, due to which the modified limiting layer has a coefficient of friction intermediate between liquid and limiting lubrication. Friction modifiers are used in oils to reduce the coefficient of friction between metal surfaces.

MONITORING

Monitoring the condition of oil and equipment and preventing its failure.

MONOETHYLENE GLYCOL

Ethylene glycol (glycol; 1,2-dioxyethane; ethanediol-1,2), HO-CH2-CH2-OH is a dihydric alcohol, the simplest representative of polyols. When purified, it is a clear, colorless liquid with a slightly oily consistency. It is odorless and has a sweetish taste. Toxic. The ingress of ethylene glycol or its solutions into the human body can lead to irreversible changes in the body and to death. Ethylene glycol was first obtained in 1859 by the French chemist Wurtz from ethylene glycol diacetate by saponification with potassium hydroxide and in 1860 by hydration of ethylene oxide. It did not see widespread use until World War I, when it was made in Germany from dichloroethane to be used as a substitute for glycerin in the manufacture of explosives. In the United States, semi-industrial production began in 1917 through ethylene chlorohydrin. The first large-scale production began with the construction of a plant in 1925 near South Charleston (West Virginia, USA) by the Carbide and Carbon Chemicals Co. (English). By 1929, ethylene glycol was being used by virtually every dynamite manufacturer. Due to its low cost, ethylene glycol has found wide application in technology:

As a component of automotive antifreeze and brake fluids, accounting for 60% of its consumption. A mixture of 60% ethylene glycol and 40% water freezes at -49°C. It is corrosive, therefore it is used with corrosion inhibitors.

  • It is used as a coolant with a content of not more than 50% in heating systems (mainly private houses).
  • As a coolant in the form of a solution in cars, in liquid cooling systems for computers.
  • In the production of cellophane, polyurethanes and a number of other polymers. This is the second main application.
  • As a solvent for dyes.
  • in organic synthesis.
DETERGENT

An additive used in fuels or lubricants to clean the internal parts of an engine when they are used.

SOAP (as applied to lubricants)

A base or thickener, usually metallic, used in mixture with oils to make lubricating greases. Compound of a fatty acid and a metal hydroxide. By choosing the right fatty acid and metal hydroxide (calcium, lithium, aluminium), the properties of the soap, such as water resistance and temperature stability, can be changed.

SWELLING / SHRINKAGE

Under the influence of lubricants, vapors or gases, sealing materials made of rubber, elastomers, etc., can undergo undesirable changes, leading to a change in their dimensions.

NAGAR

Carbon deposits of considerable thickness formed on engine parts that become very hot during operation. Nagar has a thickness of tenths of a millimeter or more. It covers the surfaces of the parts that form the combustion chamber, the piston grooves and its firing bridge, the inner surface of the piston crown, the parts of the exhaust system and the exhaust ports of two-stroke engines. Depending on the composition of the oil and the conditions for the formation of carbon deposits, there are different hardness. The most unfavorable effect on the operation of the engine is the formation of thick hard deposits in the grooves of the compression rings, on the fire bridge of the piston. It is accompanied by bursting and scuffing of rings and cylinders or polishing of cylinders. Carbon formation on the bottom of the piston from the inside disrupts the cooling of the pistons with oil and leads to emergency consequences (burnout or scuffing of the pistons, breakage of the connecting rods). Nagar consists mainly of carbon, oxygen and inorganic compounds formed during the combustion or actuation of metal-containing additives to oils and fuels.

WELDING LOAD

It is defined as the smallest load, upon reaching which the mechanism jams and the friction pairs seize. The welding load is determined on a four-ball friction machine and characterizes the extreme pressure (EP-Extreme Pressure) properties of the grease. This test method is regulated by DIN 5151 350/4. The essence of the method is as follows: Three steel balls are placed in a cup and lubricated with the investigated lubricant, and the fourth is placed on top between them; this ball rotates relative to three balls at a given speed. The load is increased in increments until the rotating ball is welded to the three stationary balls.

NAPTHENIC HYDROCARBONS

(NAPHTHENS, CYCLOALKANES, CYCLOPARAFFINS, POLYMETHYLENE) - a class of carbocyclic compounds consisting of methylene groups closed in a ring and having the general formula SpH2p - An integral part of oils, fuels, oils and other petroleum products. They have a high calorific value and a low pour point.

NEUTRAL OILS

Refined paraffin oil bases.

UNSATURATED (UNSATURATED) HYDROCARBONS

A class of acyclic compounds containing double or triple bonds between carbon atoms in the molecule. They are not part of the oil, but are formed during its processing. They are divided into olefinic (with one double bond), diolefinic (with two double bonds) and acetylenic (with one triple bond). They have low chemical stability and are an undesirable component of gasolines, diesel fuels and lubricating oils.

NON-WORKING PENETRATION

The consistency of the grease or paste at rest, i.e. in the condition in which the material is supplied.

INSOLUTION IMPURITIES

Wear products, dust and other solid contaminants that are normally present in used oil.

UNBURNED PRODUCTS

Unburnt fuel or gases resulting from worn piston rings and gaskets that saturate, contaminate, or thin the oil used in the engine.

PETROLEUM PRODUCT

A product obtained from oil refining.

PETROCHEMISTRY

Branch of chemistry that studies the properties of oil, methods of its processing and properties of products obtained from oil.

PETROLEUM OILS

Crude oil base oil types with saturated hydrocarbons containing at least one closed ring of carbon atoms. petroleum oil bases are characterized by low freezing point, good water repellency and high solvent power.

LOW TEMPERATURE PERFORMANCE

A characteristic of mineral oil products that describes cloudiness, filterability, fluidity, freezing point, crystallization points.

SCORING

Marks on metal in the form of grooves caused by machining or abrasion.

AUTO MANUFACTURERS APPROVALS

Automakers may have higher requirements for oils. Without waiting for the next international specifications, they declare their original test methods. After checking the effectiveness of the best oils receive “approvals” for use from a specific manufacturer:

  • for passenger cars: Mercedes-Benz, Renault, Peugeot, Volkswagen, Citroen, Ford, Fiat, Porsche, BMW, etc.
  • for trucks: MAN, MB, Volvo, RVI, etc. For example, MB-APPROVAL 229.1, BMW Longlife-04, VW 500.00 and VW 505.01.
SCALE

Solid product, consisting mainly of oxides and formed on the surface of metal products when heated in an oxidizing (eg atmospheric) environment.

OIL OXIDATION

The natural change in the properties of the lubricant under the influence of atmospheric oxygen, high temperatures, loads and the catalytic action of metals. This leads to destruction, polymerization and a number of other chemical transformations. At the same time, due to the formation and accumulation of oxygen-containing compounds (alcohols, aldehydes, ketones, etc.) and carbonaceous compaction products, the composition of the oil changes, and its performance characteristics deteriorate. Typical signs of oxidation are a change in color, odor, an increase in viscosity, the appearance of substances that precipitate. Significantly slow down the oxidation process is possible with the use of antioxidants.

OCCLUSION

1. Capture of the substance of the medium by crystals growing in it.

2. Sorption of gases by melts, usually metals.

RESIDUE COMPONENT (BRIGHTSTOCK)

High viscosity oil base that is temperature stable and produces a strong lubricating film, particularly under high temperature conditions.

SAMPLE SELECTION

Methods for sampling oil and oil products from tanks, underground storages, bulk carriers, railway and road tanks and pipelines, as well as barrels, cans, canisters and other shipping containers are established by GOST 2517. A combined sample of an oil product is taken by a stationary sampler in one step or is several point samples taken in compliance with the requirements of the standard from a certain level of the tank, transport tank or from one container (canister, barrel, etc.). In case of arbitration analysis, a control sample is retained, which is part of the pooled or incremental sample. Sample volumes of fuels, lubricants and special fluids for analysis are given in the regulatory documentation for specific types of products.

USED ​​PETROLEUM PRODUCTS

Waste oils, oil flushing liquids, as well as mixtures of oil and oil products formed during cleaning of storage, transportation facilities or extracted from oily waters. Must be collected by brands, varieties, groups or subgroups in accordance with GOST 21046.

CLEANING OF OILS BY ADSORPTION

The process of purification of oil distillates based on adsorption on adsorbents (natural bleaching earths or clays) from undesirable impurities present in oils (resins, naphthenic acid soaps, acid tar, sulfonic acids, mineral acid residues and selective solvents). In percolation adsorption purification, the distillate (in pure form or with a solvent) is filtered through a layer of granular adsorbent. In contact cleaning, it is mixed with a finely divided adsorbent (at low (80-90°C) or elevated (100-300°C) temperatures), followed by separation of the adsorbent by filtration.

OIL CLEANING ACID

It consists in the treatment of oil distillates with sulfuric acid or oleum (fuming sulfuric acid) with subsequent removal of the residue (acid tars). Oils after acid cleaning contain undesirable acidic products in small quantities, therefore, as a rule, they are subjected to subsequent treatment with alkalis and adsorbents (bleaching clays, etc.). Acid cleaning produces a large amount of acid tar, which is difficult to dispose of and pollutes the environment. It is used mainly in the production of white oils.

SELECTIVE OIL CLEANING

The process of treating oil distillates with selective (selective) solvents (sulfur dioxide, nitrobenzene, phenol, furfural, n-methylpyrrolidone, etc.) in order to remove unwanted components of oil distillates (aromatic hydrocarbons, resins, asphaltenes, etc.) by extracting liquid with liquid. A variety of selective purification is the “duosol process”, in which two solvents that do not mix with each other are used. The purified distillates are called selective raffinates.

ADDITIVE PACKAGE

A balanced mixture of additives for various functional purposes, which makes it possible to obtain a commercial oil product with the required properties and a given quality.

PARAFFIN OILS

Types of oil bases having a high molecular weight and containing oily waxes.

PARAFFIN HYDROCARBONS

MSDS

Or the Material Safety Data Sheet (MSDS) is a document designed to inform plant workers and emergency personnel about the safe handling procedures for specific substances or mixtures of substances. The safety certificate contains information about physical characteristics (melting point, boiling point, ignition point, etc.), toxicity, health effects, first aid methods, chemical activity, storage, processing conditions, use of protective equipment and special equipment, methods of disposal.

PASSIVATION

1. During friction, a thermodynamically inevitable process of interaction of mechanically activated friction surfaces with active components of the lubricating medium with the formation of secondary structures.

2. During corrosion - the formation of an oxide film on the surface, which prevents the development of the corrosion process.

PASTES

Lubricating and assembly pastes are, in fact, greases containing a higher amount of solid additives to improve their lubricating properties. Depending on the amount of filler, there are: lubricating pastes - from 10 to 40%, mounting pastes - over 40%. In mounting pastes, the filler can also act as a thickener. Pastes are used when conventional oils and greases cannot withstand harsh operating conditions. For example, often when operating at low speeds, the resulting lubricating film is not thick enough to separate the contact surfaces, which causes wear (seizure). The presence of solid additives in the lubricant solves this problem. Separately, it is worth mentioning pastes containing reactive white fillers, which in tribocontact under the action of loads and temperatures are able to form active layers on metal surfaces, reducing friction and protecting against wear even under extreme loads. White fillers are usually various inorganic compounds.

PENETRATION

A value that takes into account the depth of penetration into the lubricant, measured in 0.1 mm, of a standard cone under the influence of its own weight under certain environmental conditions. For example, a penetration of 26.5 mm is 265 x 0.1 mm. Typically, greases that have been in service for some time become softer, in connection with which a distinction is made between working and non-working penetration. The consistency of lubricants is determined by the value of the working penetration, which is reflected in the NLGI classes. It is generally accepted that penetration is a conditional empirical indicator that has no physical meaning and does not characterize the performance properties of lubricants, however, this indicator is used to assess volumetric and mechanical properties.

FOAMING

Oil captures air bubbles. Reduced with additives that inhibit foaming. Bubbles reduce lubricity and promote oxidation.

PEPTIZATION

Spontaneous dispersion, manifested in the form of a transition into a colloidal solution of the precipitate formed during coagulation.

DISTILLATION

Method and process for the separation of liquid mixtures, based on the difference in the composition of the liquid from the composition of the vapor formed from it; is carried out by partial evaporation of the mixture of liquids to be separated, followed by condensation of the resulting vapors.

GREASE

This is a lubricant, which includes a base oil - a base, a thickener - soaps, solid hydrocarbons, often a stabilizer to maintain the uniformity of the lubricant, sometimes a filler (for example, graphite). Lithium, calcium, sodium or mixed (lithium-calcium) soaps are commonly used as thickeners. A distinctive feature of greases is that, depending on the operating conditions, they are capable of possessing the properties of solid or liquid substances. Under the action of small forces, lubricants behave like a solid body, that is, they can be held on vertical and inclined planes. If there are large loads, lubricants work like a liquid (have fluidity). This property was the reason why lubricating greases are very widespread. They are used in friction units, to which it is impossible to continuously supply oil, as well as at high specific loads and low speeds, in difficult-to-seal units. Lubricants reduce friction and wear and protect surfaces from corrosion.

DENSITY

This is a physical quantity determined by the mass of a substance per unit volume (kg/m3, g/cm3). Density depends on temperature: with its increase, density decreases and vice versa. The ratio of the densities of two substances under certain standard physical conditions is called the relative density (dimensionless value).

POLYALPHAOLEFINS (PAO)

Synthetic oils based on PAO form the IV group of base oils according to the API classification. They make up about one third of all synthetic oils, are distinguished by universal lubricating properties, can operate in a wide temperature range, have a high viscosity index and stability of properties throughout the entire service life, do not cause corrosion of metals, do not form carbon deposits and deposits, do not adversely affect materials gaskets and seals, mix well with mineral oils.

SEMI-SYNTHETIC OIL

This is a mixture of mineral and synthetic base oils, and can contain from 20 to 40 percent "synthetics" in its composition. There are no special requirements for manufacturers of semi-synthetic lubricants regarding how much synthetic base oil (synthetic component) should be in the finished engine oil. There are also no regulations on which synthetic component (group III or group IV base oil) to use in the manufacture of a semi-synthetic lubricant. According to their characteristics, these oils occupy an intermediate position between mineral and synthetic oils, i.e. their properties are better than conventional mineral oils, but worse than synthetic ones. At a price, these oils are much cheaper than synthetic ones.

ADDITIVES

These are synthesized chemical compounds introduced into the base oil to improve properties during periods of operation and storage. Additives are used in concentrations from a few ppm (in the case of antifoam agents) and up to 20% wt. and more. They can both enhance each other's properties due to synergy and cause antagonistic effects. Some additives are multifunctional products that reduce the possibility of negative impact on each other. Additives may not affect all properties. For example, they cannot change air release, thermal stability, compressibility, boiling point, thermal conductivity, etc. Well balanced and optimized additive systems can dramatically improve lubricant performance.

WEAR PRODUCTS

These are particles of metals and alloys, as well as metal oxides or their compounds with sulfur, phosphorus and other elements that are part of oil additives that may be present in the operating oil. The size, shape, color of the particles depend on the nature of the wear process and the lubrication regime. Typically, particle sizes range from tenths of a micrometer to 10-15 microns. With intense abrasive wear or fatigue spalling, scuffing, larger particles are found in the oil. When operating on oils with different levels of performance properties and in engines of different designs, the content of metals in the oil corresponding to the normal and faulty state of friction parts can vary greatly.

ENGINE OIL PUMPABILITY

This is an indicator characterized by low-temperature dynamic viscosity of the oil at a low shear rate gradient, measured on an MRV viscometer according to the ASTM D 4684 method. C for the least viscous oils of class 0W to -15C for the most viscous oils of class 25W. Such values ​​of dynamic viscosity in the absence of shear stress during its measurement guarantee a stable oil pressure in the main line of the lubrication system and a rapid supply of oil to the most distant parts of the engine, lubricated under pressure, when the engine is turned by the starter during a cold start.

POIS

Unit of measure for dynamic viscosity. One poise is equal to the viscosity of a liquid that resists a force of 1 dyne to the mutual movement of two layers of liquid with an area of ​​​​1 cm², located at a distance of 1 cm from each other and mutually moving at a relative speed of 1 cm / s.

OIL CONSUMPTION

The sum of oil consumption for waste and oil consumption per shift. Oil consumption for waste is due to the transfer of oil by piston rings from the cylinder walls to the combustion chamber and the evaporation of light oil fractions during heating. Typically, leaks through the seals and from the turbocharger are also included in the waste oil consumption. Expressed in liters per 1000 km. mileage or as a percentage of fuel consumption. The oil consumption per shift is equal to the ratio of the capacity of the engine lubrication system to the assigned oil resource or engine operating time between oil changes according to its condition, i.e. from the moment the engine is filled with fresh oil until the oil fails.

REGENERATED OIL

This is a technical oil obtained by refining used oil by physical, chemical or physico-chemical methods, with performance properties restored to the requirements of regulatory and technical documentation.

GROWTH OF OIL VISCOSITY

During the operation of oil in a piston engine, an increase in viscosity occurs, which is due to the evaporation of the most volatile low-viscosity fractions from the oil film on the cylinder walls, the oxidation and nitration of base oil hydrocarbons with the formation of soluble and insoluble products that thicken the oil, external contamination of the oil with insoluble particles (mainly soot particles ). The increase in oil viscosity has a number of negative consequences. The pumpability of the oil deteriorates, the cold start of the engine becomes more difficult, friction losses increase during the hydrodynamic lubrication regime and fuel consumption increases, heat removal from parts cooled by oil and the efficiency of oil cleaners decrease. For these reasons, the upper limit of oil viscosity is always an indication of the limit state of the engine oil.

SOOT

This is practically pure carbon obtained by regular combustion of liquid or gaseous hydrocarbons in the presence of a given amount of air, which does not ensure complete combustion.

SEDIMENTATION

This is the settling or floating of particles of the dispersed phase (solid grains, liquid droplets, gas bubbles) in a liquid or gaseous dispersion medium in a gravitational field or in a field of centrifugal forces. The sedimentation rate depends on the mass, size and shape of the particles, the viscosity and density of the medium, as well as the acceleration that occurs when the particles are subjected to field forces.

SYNERGISM

This is the sum of the positive effects of two or more additives on the property or properties of the oil, which exceeds the sum of the effects of each additive separately. Synergism is more often manifested by additives that have different mechanisms of action or interact in such a way that the synergistic additives work slows down.

SYNTHETIC ENGINE OILS

These are oils made on the basis of synthetic base oils (synthetically obtained from liquid or gas chemical compounds) - PAO, ethers and dialkylbenzenes or mixtures thereof. Compositions of additives for synthetic oils are created taking into account the specifics of their acceptance to additives, as well as the solubility of the latter in synthetic oils.

LUBRICATION OF BALL BEARINGS

Greases for rolling bearings are often lithium saponified greases, as well as sodium soap greases for special applications, such as calcium soap greases for applications with very heavy water presence.

LUBRICANT AND COOLING LIQUIDS (COOLANTS)

This is a technical fluid introduced into the workpiece processing zone by cutting or pressure. They are divided into oil and water miscible. They are multicomponent systems. In addition to petroleum or synthetic oil and water used as a base (base component), they contain combinations of additives for various functional purposes. The contact of the cutting tool, die, matrix or roll with the material being processed and chips occurs at high pressures and temperatures. As a result, significant friction forces arise. Under these conditions, the main purpose of the coolant is to lubricate the friction surfaces, remove heat from them, facilitate the process of metal deformation, remove chips, metal filings and dirt from the cutting zone. Due to this, cutting forces or metal deformation forces and power consumption are reduced, increases tool life and improves product quality. In addition, the coolant temporarily protects the workpiece and equipment parts from corrosion.

LUBRICITY

This is the property of a lubricant to reduce wear and friction, regardless of its viscosity. Lubricity is of great importance in boundary lubrication. Under boundary lubrication conditions, oils having a higher lubricity provide the least friction and wear, and also prevent seizing of friction parts. The most common methods for assessing the lubricity of oils are mechanical tests on instruments and friction machines.

OIL CHANGE

This process must be carried out in accordance with the requirements of the equipment manufacturer in the established intervals of operating time or mileage. It is permissible to change the oil according to its condition indicators where regular sampling of the operating oil from the engine lubrication system and analysis are carried out according to the limit state indicator established for the oil of a particular brand during its operation in a given engine of a given technical object.

LUBRICANT COMPATIBILITY

This is the ability of two or more lubricants to mix with each other without deteriorating their performance properties and storage stability.

OIL AGING

This is a set of processes accompanied by a change in the composition and properties of the oil working in the engine, and most of the changes entail a decrease in the performance of the oil. the most significant aging processes are oil oxidation under the influence of high temperature, an oxidizing environment and catalysts - wear and corrosion products; pollution by products of incomplete combustion of fuel, dust; depletion of the effective action of additives consumed in neutralization reactions, dispersion of contaminants, inhibition of oxidative processes; dilution of oil by fuel; mechanical and thermal destruction of viscous additives; evaporation of light fractions of the base oil.

STOKES

This is the unit of kinematic viscosity. One stokes is equal to the kinematic viscosity at which the dynamic viscosity of a medium with a density of 1 g/cm³ is equal to 1 poise. Kinematic viscosity is equal to the ratio of dynamic viscosity to the density of the medium and gives the concept of the viscosity of the medium under certain conditions - under the influence of gravity. This is due to the method of measuring viscosity in a capillary viscometer, when the time of fluid flow from a calibrated container through a hole under the action of gravity is measured.

SULFATE ASH

This is the ash content of an oil or other lubricant, determined by treating the residue with sulfuric acid and then evaporating it to dryness. Expressed in % wt. During operation, ash deposits can form on the piston crown, valve tulips, spark plugs, and the cylinder head on the side of the combustion chamber. Ash deposits almost entirely consist of inorganic combustion products of oil containing poorly soluble organometallic substances (detergent and antioxidant additives, friction modifiers). To prevent the formation of ash deposits, the sulfate ash content of oils and their waste consumption are limited, and additives with metal combinations that are less prone to the formation of ash deposits are used.

SOLID LUBRICANTS

Solids that are injected between sliding surfaces to reduce friction and wear and prevent seizing, cold welding and galling.

FLASH TEMPERATURE

The fire hazard characteristic of an oil product is the temperature at which the product, heated under the conditions established by the standard, ignites when a flame is brought to it and burns for at least 5 s; determined according to GOST 12.1.044.

FLASH POINT

Characteristics of the fire hazard of an oil product - the minimum temperature at which a short-term ignition of an oil product vapor from a flame occurs under test conditions; t.v. is determined in devices with an open (GOST 4333) or closed (GOST 6356) crucible.

FREEZING POINT

The lowest temperature at which the oil will flow freely under test conditions. It is possible to achieve a lower freezing point with an additive.

POUR POINT

Characteristics of low-temperature properties (GOST 20287) - the temperature at which the oil product loses its mobility.

DROPPING POINT

The temperature at which a lubricating grease changes state from a ductile solid or semi-solid to a liquid and, under standard test conditions, begins to flow out of the tube.

BOILING TEMPERATURE

The temperature at which a chemically homogeneous substance boils.

CRYSTALLIZATION TEMPERATURE

The temperature at which a cloud of paraffin crystals appears in the product liquid under controlled test conditions according to DIN ISO 3015.

MELTING TEMPERATURE

The temperature at which a solid changes to a liquid state when heated.

TEMPERATURE STABILITY

Lubricant properties to resist oxidation at high operating temperatures.

THERMO-OXIDATIVE STABILITY

An indicator characterizing the antioxidant properties of oils (GOST 23175); determined by the time during which a thin layer of oil turns into a varnish film; the higher the t.s., the slower the oil will oxidize, the less the risk of burning the piston rings when the engine is running on this oil; in jet fuels t.s. is determined according to GOST 17751 and characterizes its antioxidant properties.

THIXOTROPY

This is a specific property of coagulation structures after their destruction as a result of mechanical action to spontaneously recover in time. The essence of thixotropy lies in the fact that bonds that have been destroyed by mechanical action. They are restored as a result of random successful collisions of particles in Brownian motion. Thixotropy is an important property of lubricating greases, gels and pastes, which manifests itself during the production of products and during their storage and use.

TITER

Number of grams of solute in 1 ml of solution.

TITRANT

A solution of a reagent, or a gas mixture containing it, at precisely known concentrations, used in titrimetric analysis.

TITRATION

Method and process for determining the concentration of a solution by gradually adding to it a controlled amount of a titrant that reacts with it until the end point of the titration is reached.

TOXICITY

Environmental indicator; reflects the impact of the oil product and products of its combustion and decomposition on humans and the environment.

BRAKE AND SHOCK ABSORBER FLUIDS

Group of liquid working media for hydraulic systems; the first ones are used as a working fluid for the hydraulic drive of the brake system of a car, the second ones - as a liquid medium in telescopic and lever-cam shock absorbers of cars; widespread brake fluids are mixed products BSK, GTZH-22, GTZH-22M, Neva, Tom, Rosa, etc.; shock absorber fluids - AZh-12T, AZh-170, MGP-10, etc.

TRANSMISSION OIL

Lubricating oils for industrial gears: DIN 51509, 51517-1/-2/-3 (C, CL, CLP lubricating oils), for vehicle gears in accordance with API GL 1 to 6 GL, SAE classes: DIN 51512.

FRICTION

Slip resistance of two surfaces relative to one another.

TRIBOLOGY

The science concerned with the study of the relationship between friction, wear and lubrication, as well as the properties of lubricants, and the implementation of the results of these studies in technology.

HYDROCARBONS

Individual organic compounds, consisting of carbon and hydrogen, with different structures and ratios between the elements. There are three classes of hydrocarbons: paraffinic, naphthenic, aromatic. Hydrocarbons of a mixed structure are widespread: naphtheno-paraffin, naphthene-aromatic, aromatic-paraffin. Almost the entire mass of oil consists of hydrocarbons.

UNIFICATION

Selection of the optimal number of varieties of products, processes, services, values ​​of their parameters and sizes.

ADHESION PROMOTIONERS

Tackifiers are additives added to oils and greases to improve adhesion (e.g. polyisobutene).

FIXANALS

Factory-sealed glass ampoules containing a strictly defined (usually 0.1 mol) amount of a chemical compound; intended for the preparation of titles.

FILTERABILITY

With regard to motor oils in the API and ILSAC classifications, it is customary to characterize the decrease in the filtration rate when the oil is watered. The determination method was developed by General Motors (GM 9099P). Permissible reduction in filtration rate can be no more than 50% (for oils used in gasoline engines of passenger cars).

REFLUX

Part of the distillate returned to the top plate of the distillation column for its irrigation.

FLOCCULATION

A type of coagulation in which the particles of the dispersed phase form loose flocculent aggregates (flocculi).

MOLDING OIL

An oil used in molds during casting or molding to keep the material from sticking to the mould.

FRACTION

Part of an oil or oil product that boils away within a certain temperature range.

FLUOROSILICONES

Silicones that contain fluorine atoms in the molecule.

CAPACITY CHARACTERISTICS

Rheological properties (flow ability) are associated with viscosity, viscosity-temperature, relaxation, adhesion and other characteristics of oils.

CHEMOSORPTION

Adsorption accompanied by chemical interaction between sorbate and sorbent molecules.

CHEMICALLY INERT

(lubricating agent) that does not enter into chemical reactions with certain substances.

COLOR OF PETROLEUM PRODUCTS AND LUBRICANTS

An indicator of oil products, determined either visually or using a colorimeter (GOST 20284); based on a comparison of the color of the test sample with the color of a reference glass or standard solution in colorimeters; leaded gasolines are painted in accordance with regulatory documentation; The color of pure mineral oils (without additives) is an indicator of the degree of refinement of the oil and its origin. The color of lubricating oils depends on the origin, processing and degree of oxidation. Most commercial oils are darker in color than base oils. Color has nothing to do with quality. Color determination with ASTM colorimeter: DIN ISO 2049, Sayboldt color number: DIN 51 411.

CENTRALIZED LUBRICATION SYSTEM

This is a method of dosed supply of lubricants (consistent or liquid) to the friction units of mechanisms, widely used in industry and production. The main parts of the CSS are the reservoir where the lubricant is placed, the pumping unit, system control devices, control units and other auxiliary devices. The centralized lubrication system is designed to reduce equipment wear, prevent premature wear of rubbing surfaces and overall control over the operation of all system components.

CHAIN ​​REACTIONS

Chemical reactions in which active particles participate - atoms, free radicals, etc., and as a result of the interaction of the active particle with the original molecule, new active particles are formed that react with the original molecules, which causes chains of transformations. C. r. in which, as a result of the interaction of an active particle with a molecule, one new active particle is formed, they are called unbranched (discovered by Bodenstein), if two or more active particles are formed, branched (discovered by N. N. Semenov).

CETAN NUMBER

Method for determining the ignitability of diesel fuel. The higher the cetane number, the better the quality of the fuel.

FOUR-BALL FRICTION MACHINE

It is one of the earliest known testing devices for liquid and grease lubricants. The device allows you to determine the wear rate and the coefficient of friction of the material. Despite its simple design, it also allows the critical loads of lubricants and oils to be determined through widely used weldability tests. This device is a ball fixed in a roller bearing, rotating at a constant speed and in contact with three fixed balls. A lubricant is applied to the contact surface. By gradually increasing the axial force, and with it the contact pressure, it is possible to determine the welding load, the wear rate and the coefficient of friction. In the process of increasing the axial load, a wear mark appears on the stationary balls, which characterizes the tested lubricant.

BASE NUMBER

Indicator (GOST 11362), which characterizes the ability to convert acidic products formed in the engine as a result of fuel combustion and oil oxidation into neutral compounds; in modern oils, the neutralizing ability is provided mainly by the introduction of ash detergent additives; usually set the lower limit of the h.h.; expressed in mg KOH/g.

ELASTO-HYDRODYNAMIC GREASE

Conditions under which the lubricant, subjected to high loads and at high operating speeds, increases viscosity and, due to its elasticity, takes on the deformation of rubbing surfaces.

ELECTROLYSIS

Chemical reactions occurring under the influence of electric current on electrodes in solutions and melts of electrolytes, as well as solid electrolytes.

ELECTROLYTES

Systems that have ionic conductivity in the liquid or solid state.

ELECTRONEGNATIVITY

A quantitative characteristic of the ability of atoms of a chemical element to polarize the covalent bonds they form.

EMULSIFIER

A substance that promotes the formation of a stable emulsion (for example, oil with water).

EMULSION

(novolat. emulsio; from lat. emulgeo - milking, milking) - a dispersed system consisting of microscopic drops of a liquid (dispersed phase) distributed in another liquid (dispersion medium). Emulsions can be formed by any two immiscible liquids; in most cases, one of the phases of emulsions is water, and the other is a substance consisting of weakly polar molecules (for example, liquid hydrocarbons, fats). One of the first emulsions studied was milk. In it, drops of milk fat are distributed in the aquatic environment. Emulsions usually belong to coarse systems, since the droplets of the dispersed phase have sizes from 1 to 50 μm. Low concentration emulsions are unstructured liquids. Highly concentrated emulsions are structured systems. The type of emulsion depends on the composition and ratio of its liquid phases, on the amount and chemical nature of the emulsifier, on the method of emulsification, and some other factors.

  • Direct, with drops of a non-polar liquid in a polar medium (such as "oil in water"). For oil-in-water emulsions, water-soluble soaps (sodium and potassium salts of fatty acids) can serve as good emulsifiers. The molecules of these compounds, being adsorbed on the interface, not only reduce the surface tension on it, but due to the regular orientation in the surface layer create a film in it that has mechanical strength and protects the emulsion from destruction.
  • Reverse, or invert (such as "water in oil"). For a water-in-oil emulsion, water-insoluble soaps (calcium, magnesium and aluminum salts of fatty acids) can be good emulsifiers.

A change in the composition of emulsions or external influences can lead to the transformation of a direct emulsion into an inverse one or vice versa. Also, emulsions are divided into lyophilic and lyophobic.

  • Lyophilic emulsions form spontaneously and are thermodynamically stable. These include the so-called. critical emulsions formed near the critical temperature of mixing of two liquid phases, as well as some cutting fluids.
  • Lyophobic emulsions arise during mechanical, acoustic or electrical emulsification (dispersion), as well as due to the condensation formation of droplets of the dispersed phase in supersaturated solutions or melts. They are thermodynamically unstable and exist for a long time only in the presence of emulsifiers - substances that facilitate dispersion and prevent coalescence (fusion). Effective emulsifiers are micelle-forming surfactants, soluble macromolecular substances, some highly dispersed solids.

Emulsions are formed in two ways.

  • By crushing drops. This method is carried out by slowly adding the dispersant to the dispersion system in the presence of an emulsifier with continuous and strong stirring. The main factors that determine the degree of dispersion of the particles of the resulting emulsion and its stability are the speed of mixing, the rate of introduction of the dispersed substance, its amount, the nature of the emulsifier and its concentration, temperature and pH of the medium.
  • By the formation of films and their rupture into small drops. The mechanism of education is as follows. The liquid forming the dispersed phase (eg oil) forms a film when slowly added to the dispersion medium. This film is torn by air bubbles emerging from the opening of the tube, which are located at the bottom of the vessel. Small single drops are formed. At the same time, the air bubbles vigorously stir the entire liquid and thereby further emulsify. Currently, to obtain a concentrated oil-water emulsion, it is subjected to ultrasound.
ESSENTIAL OILS

Compounds of acids and alcohols used for lubrication and the production of greases.