V. L. Lashkhi's research while affiliated with Gubkin Russian State University of Oil and Gas and other places
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Publications (90)
The possibility to predict the tendency of an oil to form high-temperature deposits in internal combustion engines on the basis of the analysis of an oil that have operated is considered. A dimensionless criterion (M) for the evaluation of this tendency is introduced. It was found that the combination of the gain in the acid number and the content...
Etude des possibilites de caracterisation des huiles lubrifiantes usagees dans un moteur diesel a l'aide d'indicateurs calculables a partir de mesures telles que la variation de viscosite par exemple. L'utilisation des ces indicateurs permettrait de remplacer l'huile moteur en fonction de son degre de degradation reel ce qui induirait des reduction...
The basic principles of formal chemical kinetics are used for an unbiased information content analysis of both the conventional and newly developed methods for evaluating the operational properties of lubricating oils. The principle proposed for enhancing the reliability of laboratory testing is based on the synthesis of sets from individual indice...
The level of theoretical elaborations in chemmotology is analyzed, in general form and their role in the formation of the science is assessed. Analysis of development of theoretical bases of chemmotological studies is restricted by the most representative areas. They include surface and volumetric properties of the systems, on which service indices...
Specific features of colloid structure of petroleum oils are considered. Motor oils are the most complex colloid systems. Efficiency of diverse additives is shown. It is pointed out that depressor and viscous, detergent-dispersive, antiwear and anticorrosion additives in optimal concentrations are modifiers of oil colloid structure, they regulate t...
The most characteristic examples, indicating relation between service properties of an oil and its viscosity, were considered. The influence of viscosity on reliable operation of friction units was considered. It is shown that viscosity is the most important and objective characteristic of oils, determining their choice for the given friction unit,...
The role of detergent additives on the basis of stabilized dispersions of calcium carbonate in lubricating effect of oils on petroleum (I-20A, M-11) and synthetic bases (poly-α-olefin oil) was shown. Results of evaluation of lubricating properties of the oils with different additives - alkaline sulfonate (A), alkaline alkylsalicylate (B) and zinc d...
New paths have been mapped out for the improvement of lubricity, in connection with the departure from the use of friction modifiers in motor oils based on molybdenum dithiophosphates and the traditional antiwear additives such as zinc dithiophosphates, trend that probably reflects the need for improving the ecological cleanliness of commericial lu...
An attempt to substantiate theoretically the principles of corrosion inhibitors (CI) efficiency determination and to optimize their choice was made, using as an example plastic lubricants, making allowances for the latter employment peculiarities. Their efficiency is mainly determined by the difference in interaction energies in the CI-metal and lu...
Analysis of the process of carbon deposit formation - typical variety of high-temperature deposits - in the area of cylinder-piston block of internal combustion engine from the viewpoint of coagulation theory was carried out. An expression is presented, which permits prediction of carbon deposit formation in an engine at a preset moment of time by...
Functional association of oil state factors and its information value was defined on the basis of analysis of statistical data of tests of native motor oils. Combination of the factors was presented by P product. P≈Δν × ΔA÷ΔB × Dr ×Db, where ν - viscosity, ΔA and ΔB were changes of acid and alkali numbers. Dr and Db were shown to be light absorptio...
Spent lubricants play a very important role in the aggravation of ecological crisis. The experimental studies conducted permitted development of a complex scheme of reprocessing spent petroleum oils and plastic lubricants with manufacture of a broad spectrum of marketable products: oils, lubricants, preservatives. The scheme was developed as applie...
The main ways of hypothetical contamination of the environment by lubricant oils (LO) at all the stages of their application: during transportation to consumer, long-term storage in tanks, service in machines and mechanisms, as well as gathering and utilization in the end of service life, were considered. It is pointed out that at all the stages th...
Surface phenomena in liquid - solid (metal) systems were considered in detail. It was emphasized that processes occuring on solid - liquid interface, as applied to chemmotological systems, determine to a considerable extent the lubricating ability, anticorrosion and detergent properties of the oils. Their qualitative and, whenever possible, quantit...
An attempt of widening the idea on lubricating oils as complex colloid systems and connect of the features of colloid structure with the degree of the operation properties of the oils was undertaken.
An attempt was made to show the necessity and ways for improvement of research principles in oil chemmotology. Special attention was paid to the categorizing of the objects studied as to their complexity into levels, ranks and hierarchies. It permits within the framework of one category to determine quite strictly the possibility of oil behaviour p...
The authors attempt to show the need for and the ways of improving the principles of study in the chemmotology of oils with a view to making such a study more objective and productive and to eliminating the ineffective conventional methods which have been developed during the last few decades. It is shown that, mathematical modeling with elements o...
An extremely urgent problem exists in the use of commercial petroleum products - fuels, lubricants, working fluids - in all types of transport. Therefore, ecological requirements must be taken into account in the stage of developing these products, along with the need to optimize the service properties of the products. These requirements pertain pr...
The micellar structure of 5% solutions of sulfonate and salicylate additives in isooctane was studied by small-angle x-ray scattering. The distributions of the micelles by size in solutions of additives which differed due to the value of the initial alkaline number were obtained by integral transformation of the scattering intensity.
The lube oils used in the operation of vehicles and equipment are produced from various sources and manufacturing methods, and hence they differ significantly in properties and chemical composition. Mineral oils produced by petroleum refining have particularly broad service applications. These oils are liquid mixtures of high-boiling hydrocarbons (...
While the oil is functioning in the motor, indicators of its state of saturation and indicators of malfunction are taken for examination. Such a partition, although defining the importance and applicability of indicators, requires precision. The state of the oil (including the initial state) at each moment of time while the motor runs is characteri...
The micelle size of detergents with different compositions was studied. The sizes were determined by small-angle x-ray scattering. In a series of calcium sulfonates with different alkali numbers, the coating-forming ability as a whole decreases with increasing micelle size. The dispersing ability has an extremal nature. In a comparison of detergent...
The use of polymers as viscosity index improver additives is discussed. The influence of the molecular structure of the polymer on its thickening abilities are discussed. For the maximum thickening effect, the polymers should have a narrow molecular-weight distribution. The physicochemical properties of thickened oils are discussed and the breakdow...
Trouble-free engine operation is achieved at low temperatures by an uninterrupted supply of oil to points of friction, i.e., by the oil pumpability. It is proposed to assess the pumpability in readily available laboratory instruments such as the Hoeppler and Rheotest-2 viscometers, using as criteria the activation energy of viscous flow or the visc...
Improvements in the fuel economy of internal combustion engines is achieved by various means, including reduction of the frictional power losses. The authors examine a method of improving the antifriction properties of motor oil in the example of M-10Gâ oil by the incorporation of additives that influence the frictional force and wear. The additive...
The colloidal stability of additive solutions is a major factor determining the quality level of commercial petroleum products. This is particularly true for motor oils containing large quantities of additive with different functions (20-25%, including additives of three to six types). Colloidal stability is regarded as the capability of an additiv...
An investigation is made of motor oils with different quality levels: M-6z/10V, M-6z/10Gâ, and M-4z/8G-RK. Their oxidation susceptibility (OS) was evaluated according to the quantity of oxygen absorbed in an RSL unit at 165 C in a 5-h test; the dispersancy was evaluated according to the detergent potential at 250 C; the true detergency was evaluat...
Since many engine parts may be made of nonferrous metals, the authors investigate the corrosivity of synthetic products under motor oil service conditions. The materials for investigation were poly-alpha-olefins (PAO), diisooctyl sebacate (DOS), an isoparaffinic oil (IPO), and MS-20 petroleum oil (aviation brightstock). PAO-DOS and PAO-IPO blends w...
The anomalous nature of the pressure dependence of the wear intensity in oils with friction modifiers is explained on the basis of the concepts of solid state thermodynamics and molecular-mechanical theory. Considering the importance and promise of the friction modifiers, specifically MCM, the authors examined some aspects of their antifriction and...
The basic principles of solid-body thermodynamics are used to describe the effectiveness of the antifriction action of an oil containing oil-soluble molybdenum compounds. It is found that one of the possible indexes characterizing the thermodynamic state of such a tribosystem is the oil film critical temperature. It is shown theoretically and confi...
In connection with the need for rational utilization of petroleum products, an extensive search is being made for methods to lower the consumption of fuel in internal combustion engines. One of the possible means for improvements of engine efficiency is a reduction of the frictional power loss, as this would automatically lower the fuel consumption...
Because high-temperature antifriction additives in motor oils must have low ash content, certain ashless thiophosphates were evaluated for their antifriction properties. The ashless thiophosphates were on the whole better in antiwear and antifriction properties than corresponding dithiophosphates. The replacement of diethylenetriamine by triethylen...
Investigates the antiwear and antifriction properties of friction modifiers under moderate frictional conditions in a PF-1 tester and a ChShM (4-ball) tester, so as to obtain an idea of whether these compounds could be used in motor oils. Compares certain amidothiophosphates (obtained by the interaction of dialkyl- and bis(alkylaryl)thiophosphoryl...
This paper is concerned with properties and performance of oil-soluble high-temperature antifriction additives (OHAA) for motor oils. These additives tend to reduce the engine power lost to friction and to lower the fuel consumption. Since the processes of friction and wear are very closely interrelated, it is of interest to evaluate the effect of...
vehicles traveled over distances from 2,000 to 10,000 km during this period. The buses were fueled with emulsion containing 10-13% water. The spark advance angle was increased by 2-3 ~ over the setting used for operation on the straight gasoline. During this time of operation, there were none of the complaints of engine overheating that are usual d...
Thiodivaleriansäure (I) wird in Gegenwart des sauren Kationenaustauschers KU-3/8 mit Gemischen primärer Alkohole (II) zu den Estern (III) umgesetzt.
Water, which accumulates in additive oils during prolonged storage or service, can produce significant changes in the service properties of the oils. The lubricating properties of oils containing extreme-pressure additives are subject to the most severe changes when quantities of water up to 2% enter the oil. This paper presents results of a contin...
One of the important advantages of synthetic motor oils over petroleum oils is their lower volatility, which gives lower oil consumption in the engine. A synthetic oil based on isoparaffins, when tested at 200-250 degree C under a vacuum of about 2 kPa, shows only one-half to one-third the evaporation loss given by a polymer-compounded motor oil wi...
used today as antiwear additives for lubricating oils. These additives are multifunctional since along with their antiwear properties, they act as antioxidants and corrosion inhibitors. Many years of experience in the use of these additives has shown that they have a definitely favorable effect in engine and transmission oils. However, the use of z...
These plant tests showed that the power and economy indices of the engines after running-in were essentially the same with the ALP-2 and ALP-3 additives. When the SMD-62 engines were run-in on either additive, the developed power was 121.3 kW, and the specific fuel consumption 69.9 ~g/J. Inspection of the parts in the liner/piston group established...
A large number of methods are used in current laboratory practice to investigate the detergency of lubricating oils. But the results obtained by these methods do not always agree with those obtained from determinations of oil detergency in engines. This is explained by the fact that the laboratory methods are generally intended for the evaluation o...
In laboratory practice in the evaluation of antiwear and antiscoring (extreme-pressure) properties, friction testers are widely used in preliminary screening of lubricants with minimum expenditure of time and testing costs. Among such testers, the most widely used is the four-ball friction tester. Gear simulator rigs represent one of the subsequent...
Organotin compounds have found their widest application as fungicides and insecticides, microbiocides for wood, and additives for plastics. In view of the relatively high level of surface activity of organotin compounds, it has appeared advisable to test the feasibility of using these materials as lube oil additives. The present work was aimed at s...
The antifriction and antiwear or extreme-pressure properties of oils containing active additives depend to a considerable extent on chemical activation of the additives. The use of additives in oils leads to the development of a chemical reaction in the friction zone and a modification of the surface layers of the metal. The ability of additives to...
In a thermographic study of the thermal stability of metal-containing and ashless detergent additives for motor oils, it has been established that the best thermal stability is shown by metal sulfonates and certain succinimides, in particular a boron-containing succinimide; the poorest thermal stability is shown by detergent additives of the metal...
1.
Sulfur-, phosphorus-, and metal-containing succinimides have been synthesized, and the adsorptivity, corrosivity, and detergent-dispetsant properties of these materials have been investigated.
2.
The modification of succinimide chemical structure is accompanied by a decrease in adsorptivity with respect to metals, in the order LZ-325>LZ-325S>LZ-...
Die Oberfächenaktivität einer Reihe von phosphororganischen Schmieröladditiven (I) bis (V), ihre Benetzungseigenschaften an Metallen und ihre chemische Aktivität gegenüber diesen Metallen werden untersucht.
1.
The synergistic effect in solubilization that can be observed when a succinimide is combined with a zinc dialkyl- or diaryldithiophosphate in optimum proportions is manifested in an increase in the quantity of asphaltenes transferred by the given additive package from the sediment into colloidal solution and is also manifested in a decrease in t...
A STUDY WAS MADE OF THE LUBRICATING PROPERTIES OF SYMMETRICALLY SUBSTITUTED DIALKYL SULPHIDES HAVING THE GENERAL FORMULA S((CH/SUB 2/)/SUB N/COOR)/SUB 2/ AND THEIR DERIVATIVES.IT WAS FOUND THAT THE SUBSTITUTIONAL DIALKYL SULPHIDES HAVE BETTER LUBRICATING PROPERTIES THAN THE NONSUBSTITUTED COMPOUNDS.THE MOST EFFECTIVE COMPOUNDS WERE THOSE IN WHICH T...
1.
A study has been made of surface activity for certain esters of phosphonic acids that have been recommended as antiwear (extreme-pressure) additives for lubricating oils.
2.
Phosphonates or chlorophosphonates with low chemical activities relative to the metals that have been studied are not suitable for use as antiwear additives.
3.
The effectiv...
1.1. Oil additives of various structures (trichloromethylphosphonic acid esters, metal dialkyldithiophosphates) differ as regards heat of absorption by metals, determined microcalorimetrically.2.2. With an increase in the heat of adsorption of oil additives on metal, anti-wear properties improve on testing in a friction testing machine under low co...
The effect of esters of phosphonic acids on frictional wear under diverse loads and sliding speeds has been investigated. The efficiency of such phosphonates as anti-wear additives depends on their structure and varies with the frictional modes. Principal groups of phosphonates have been grouped as esters which are ineffective under both high and l...
From a comparison of these results with those reported in [2, 3], it will be seen that the jump in adsorption it noted for the range of concentrations coinciding with the range of critical micelle concentrations for the succinimide additive. This coincidence has been the reason for studying the adsorption of various types of additives on metal, the...
1.
By means of NMR spectroscopy, the structure of commercial samples of polyisobutenes has been defined more precisely, and the influence of this structure on the properties of polymer-compounded oils has been demonstrated.
2.
A relationship has been established between the nature of the spectrum and the molecular weight of the polyisobutene. A gra...
1.
It has been established that polymer-thickened oils are better than ordinary mineral oils in antipitting properties over the range of viscosities that were investigated.
2.
The curve relating antipitting properties to viscosity passes through a maximum both for mineral oils and thickened oils; the maximum is sharper for thickened oils.
3.
The an...
1.1. When determining the adsorption capacity of succinimide and zinc dithiophosphate type additives by the method of contact potential difference it was established that the formation of adsorption layer of succinimide is complete at a concentration of 0·1% wt., which corresponds to the upper critical concentration of micelle formation of this add...
1.The high degree of adsorptivity of a succinimide additive and the effects of zinc dithiophosphates and bisphenols on the surface activity of the succinimide have been established by measurements of interfacial tension (ring method) and electron work function (contact potential difference method).2.The characterizations of surface activity of succ...
On the basis of our experiments it was established:1.
Polyisobutylene can have a negative influence on the effectiveness of the action of antiabrasion additives (especially sulfur-containing).
2.
In repurified (highly purified) thickened oils, sulfur-containing antiabrasion additives are incompatible with polyisobutylene.
3.
Variation of the chemic...
A method has been described for evaluating the adsorption properties of oils by measuring electron work function.Using a series of oils containing additives, a connection has been shown between their adsorption properties, as determined by measuring the electron work function, and antiwear properties. A method has been described for evaluating the...
1.
It is shown that polyisobutylene of molecular weight 8000 or more is unsuitable for obtaining thickened transmission oils; the polymer should have a molecular weight of 3000–5000 for this purpose.
2.
It has been established that, with the exception of the viscosity, during operation in an automobile gear box the physicochemical properties of the...
The principal use of the ultrasonic generator UZG-0.1, one of a series of generators being manufactured, for evaluating the mechanical degradation of polymers in solution, especially highly polymerized additives, has been demonstrated.
The ultrasonic apparatus developed in this work, equipped with the catenoid concentrator, makes it possible to gr...
Citations
... To decrease the negative environmental impact of the cutting fluid, lubricants were improved either by introducing biodegradable fluids or by reducing the quantity of the biodegradable fluid used [2]. In spite of that reduction, the remaining biodegradable fluids can also be a highly subject to bacterial contamination, which is the most severe and difficult to correct type of contamination. ...
... The existence of molybdenum in a spectrochemical analysis for the MO (Table 3) suggests that the additive could be from molybdenum dithiophosphate (MoDTP) as this additive can reduce the friction in motor oil. 50 . In addition to this, the value of COF for MO (0.093) in this study is close to the COF of MoDTP additive in hydrocarbon base oil (COF ¼ 0.08). ...
... Measurements of electrophysical parameters were carried out using a constant temperature three-electrode cell and an alternating current bridge E8-2 as described in (Lashkhi et al., 1974). A 15cm 3 cell having an initial capacitance of 15.390 pF was used. ...
... This study examines the nature o[ these chemical reac-tions and their relationship to wear. A four-ball wear tester Presented as an American Society ot Lubrlcaflon Engineers paper at the ASLSASME Lubrlcation Conterence in Kansas City, ilissouri, October g-5, 1927 Voruvr 22,2,[135][136][137][138][139][140][141][142][143][144][145] is used to generate the reaction products between a superrefined paraffinic mineral oil and 52 100 steel ball bearings. ...
... The alignment of the chains in these FM layers makes compression difficult while the ease at which the bonds between these layers are broken makes shearing of the chains occur when surfaces move parallel to the layer. The layers are also easily reformed meaning that there is always a protective, sacrificial FM layer upon the surface of the metal which can provide lower friction and prevent wear [54,57]. A study by Castle and Bovington [58], where carboxylic acid based FMs with saturated, straight chain hydrocarbon are to be used to lubricate surfaces, it was found that the length of the hydrocarbon chain has a direct effect on the molecules friction reducing properties. ...
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... Metal-free ashless lubricant additives have been synthesized and proposed as a promising replacement of ZDDP with better or comparable antifriction (AF), AW, AO, and EP properties in several studies [28,[31][32][33][34][35][36][37][38][39][40][41]. Commonly recognized ashless chemistries as lubricant additive are phosphorous-and sulfur-based compounds, that is, phosphate esters [38], thiophosphates, and dithiophosphates [27,29,39,42], alkyl/aryl mono and/or di-hydrocarbyl phosphates, amine salts of aryl/alkyl-aryl or aliphatic di-hydrocarbyl thiophosphates [34], diether polysulfides [36], dithiocarbamic [33], amidothiophosphates [42], benzotriazole-thiadiazol [35], and most recently alkylthioperoxydiphosphates and alkylphosphorofluoridothioates [31,32]. ...
... Organotins derived from carboxylic acid, phosphoric group, N, S donating groups have been studied as corrosion inhibitors [11][12][13][14][15][16][17][18][19][20][21][22]. Organotins are known for their friction and wear reducing properties [23][24][25]. Organotin derivatives of alkylphenols have been successfully used as antiwear additives for lubricating oils [26]. Since organotins and dithiohydrazodicarbonamides both are well known for their biocidal behavior, friction and wear reducing properties and anticorrosive properties, synthesis of organotin complexes with dithiohydrazodicarbonamides was undertaken with intent to explore their applicability as corrosion inhibitors. ...
... A polymer with higher molecular weight and narrower molecular weight distribution usually possesses stronger thickening powers. 3 In addition to the viscosity thickening power, the shear stability (often revealed by using the shear stability index, SSI, determined by the Kurt Orbahn (KO) test of the formulated lubricants) is the other primary characteristic of a polymer-based VI improver. It reflects the polymer's ability to resist shear-induced macromolecular degradation under high-shear conditions ubiquitous in most mechanical systems. ...
... This treatment can be coupled with both distillation or solvent extraction for improving the deasphalting. In fact, WLO is considered a colloidal system comprising the base oil, the additives, and the impurities accumulated during service time (Lashkhi et al., 1992). The stability of these constituents is mainly due to electrostatic repulsive forces between the particles. ...
... In the simplest sense, it is clear that low temperatures have a thickening effect on the condition of oils. Viscosity is a property of a substance to resist external influences that cause its flow [1]. Consequently, at a low temperature mode, the oil flow and pump ability through the channels of the lubrication system slow down. ...
