bluuebunny/crossref_metadata_2025_split huggingface dataset:
Frictional behaviour of experimental synthetic and semi‐synthetic gear oils
Authors: Godet A. , Roussel G. , Thebault M. 
Published: July 2006

AbstractThe use of synthetic and semisynthetic lubricants combined with a proper selection of additives, can help reduce friction between gear teeth, as shown on a tribometer simulating gear tooth contact. Accurate efficiency measurements on a loaded industrial power divider show good agreement with friction measurements on the tribometer, except for the viscosity effects that appear not to be significant in the simulated gear tooth contact and are an influencing parameter in the gear box. Changing the viscosity grade from 320 to 100 can reduce the friction losses by about 20%, but such an improvement has been found with a fully synthetic lubricant with a very high performance additive treatment, without any risk since the viscosity grade was 220. The effect of the additive was assumed to be about 5%; the overall friction reduction was about 20%. In worm gears, significant improvements are also achieved with the synthetic oil (about 8% efficiency increase), but the best energy saving fluids appear to be polyglycol base lubricants (with a measured efficiency improvement of about 17%).
Physical properties and testing of organosilicon esters for their applicability as synthetic lubricants
Authors: Čermák J. , Sasíh M. , Kolář D. , Dobeš P. 
Published: July 2006

AbstractThe constantly growing needs of the operational parameters of machines and engines, especially for aeronautical use, have brought about greater demands on lubricating oils. Various synthetic materials have been used since the Second World War,1 in increasing quantity, as substitutes for mineral based oil: esters from organic alcohols and mono‐ or dicarboxyl acids are among the most widespread. Quite a different type of synthetic oil is organosilicon compounds, known as ‘silicones’.This paper reports experimental data for a group of silicon compounds examined in comparison with other materials normally used as bases for synthetic lubricants.
The relationship between the chemical structure of ester base fluids and their influence on elastomer seals, and wear characteristics
Authors: van der Waal G. 
Published: July 2006

AbstractThe intention of this paper is to examine the relationship between the chemical structure of ester base fluids and their influence on elastomer seals and wear characteristics. It presents background information about esters, some of which can be considered as blending components for mineral oil and/or polyalphaolefins, while others have properties so similar to mineral oil that in principle substitution is possible. It examines the effects of ester base fluids on a number of properties of elastomers, including modulus, tensile strength, elongation at break, hardness, and volume changes. It also explains a method of selecting synthetic base fluids for performance upgrading or viscosity purposes, using a ‘non‐polarity index’ which allows more speedy comparison and selection of ester base fluids.
The influence of molecular structure on the frictional behaviour of lubricating fluids
Authors: Hentschel K.‐H. 
Published: July 2006

AbstractIn order to establish correlations between the chemical structure or constitution of fluid lubricants and their friction characteristics under elastohydro dynamic conditions, a number of model test fluids were tested in a twin‐disk machine. As test fluids, special saturated mono‐, bi‐, and tricyclic compounds, alkanes and polyethers were selected. The traction coefficients were shown to be strongly dependent on the chemical structure of the lubricants and on operational parameters. High coefficient values mostly arise from lubricant molecules that are shaped unregularly, with indentations and teeth as seen with Stuart‐Briegleb models, and allowing only heavily hampered rotational intramolecular motions along single bond axes. Low traction coefficients derive from lubricant molecules with a thread‐like shape and a minimum of structural subunits or functional groups involved in significant intermolecular interactions. In order to account for the results obtained, several paradigms and hypotheses are established and discussed in detail.
Commercial developments in synthetic lubricants — a European overview
Authors: Williamson E. I. 
Published: July 2006

AbstractMany useful papers are published about the technical development and testing of synthetic lubricants and functional fluids, yet it is also important to appreciate the market environment in which these products are used. However, hard data on market shares and producers' intentions are difficult to obtain, because of the obvious demands of commercial secrecy. This paper represents the author's assessment of the European commercial context, examines recent demand for different classes of synthetic lubricant and functional fluid, and their applications, and offers a considered assessment of the situation in the 1990s.
The characteristics and applications of synthetic lubricating greases
Authors: Schateva M. , Ficko M. , Kostić S. 
Published: July 2006

AbstractBased on the need to develop indigenous synthetic base greases, the authors' organisation produced candidate greases based on polyesters of adipic acid, thickened with modified bentonites. The formulation and performance of these greases are presented, demonstrating their lubricity and stability characteristics, and conclusions are drawn as to their suitability, according to these characteristics, for various applications, including those in a petroleum‐origin fuel environment.
Silicone fluids: Synthesis, properties and applications
Authors: Huber P. , Kaiser W. 
Published: July 2006

AbstractThis paper describes the structure and derivation of ‘classical’ silicone fluids, giving the reactions for the production of dimethyl fluids by Miiller‐Rochow synthesis, polymerisation, direct synthesis, hydrosilylation, and transesterification. The properties of siloxanes are described, and the applications of silicone fluids and compounds are discussed in relation to their properties, particularly insolubility in water, viscosity‐temperature characteristics, and dielectric properties.
Antioxidant kinetics in synthetic lubricants field testing
Authors: Bigarre I. , Légeron J.‐P. 
Published: July 2006

AbstractWith the increases in engine performance, lubricants technology has quickly made great strides. The selection of mineral base oils has become more stringent, and the use of synthetic lubricants has been an important feature, allowing better perfonnance characteristics, among which is longer drain periods.1,2.These evolutions have not led to the elimination of performance additives, which must be included in the composition of every engine lubricant. Among these, antioxidants play a prominent part: they participate in the protection of the lubricant against degradation b y oxidative agents. The ways in which they act are complicated and not entirely understood even today: essentially the initiator, ie oxygen from air, reacts with the lubricant to form peroxides, and then radicals which are themselves secondary oxidative agents.According to the chemical structure of the antioxidant additives, a break in these chain reactions can occur. Thus it is important to select the best compounds for each lubricant: this can be achieved by experimentation and by specific identification of the antioxidant agents which are used.
DSC‐cell ‐ A versatile tool to study thermo‐oxidation of aviation lubricants
Authors: Zeman Alfred 
Published: July 2006

AbstractThe versatility of a differential scanning calorimetry (DSC) cell in studying thermal and/or thermal‐oxidative degradation of lubricants is shown using ester‐based aviation turbine oils as an example.The following applications are discussed: 1. quality control of fresh and used oils by pressure differential scanning calorimetry; 2. influence of metal catalysis on oil degradation; 3. identification of volatile degradation products by PDSC gas chromatography‐mass spectrometry via a TENAX trap; 4. determination of spontaneous ignition temperatures; 5. influence of metall metal oxides, wear debris and oil degradation products on ignition behaviour; 6. inhibition of spontaneous ignition by antioxidants.
Process variables in the manufacture of polyalphaolefins
Authors: James B. D. , Dain C. J. 
Published: July 2006

AbstractThe production of polyalphaolefins is described, including three catalyst systems — free radical, Ziegler‐type, and cationic polymerization. The mechanism of oligomerization is given, and the distribution of products according to temperature, time and promoter type. As this reaction is incomplete, and monomer remains, product distillation is necessary to remove this.
Lubrication of hydroelectric turbine thrust bearings with a diester‐based synthetic lubricant
Authors: Boehringer R. H. , Neff F. 
Published: July 2006

AbstractA diester‐based lubricant was found to reduce friction substantially in the thrust bearings of a hydroelectric turbine, compared with a conventional petroleum oil. Bearing temperatures were immediately reduced by 10–11 °C and bearing failures were eliminated. Revenue savings estimated at $10,000,000 per year have been made due to an increase in power production, and the elimination of repair work and downtime costs.1
Current and future polyalphaolefins
Authors: Blackwell J. W. , Bullen J. V. , Shubkin R. L. 
Published: July 2006

AbstractPolyalphaolefins currently have a market share of less than 1 per cent in Europe, but this is expected to double in the next 5 years. This paper looks at additive response, rheology, volatility, and oxidation resistance of PAOs; of particular importance are their low temperature capabilities. The results of various tests are given, in comparison with mineral‐based oils. In conclusion, research is under way to investigate the possibilities of ‘tailor‐making’ PAOs by varying production process variables and using a variety of starting olefin streams.
Viscosity properties of base lubricating oils containing mineral oil, synthetic ester oil and polymeric additives
Authors: Luksa Adam 
Published: July 2006

AbstractThis paper presents the results of investigations into the physical properties, in terms of volatility, pour point and viscosity, of a composition base oil, whose components included mineral‐and ester‐based oils, and a polymeric thickener. The presence of the ester had limited effect, and this was improved by addition of the thickener.
Development and testing of a screw compressor fluid based on two‐stage hydrotreated base oils, and comparison with a synthetic fluid
Authors: Cohen Stephen C. 
Published: July 2006

AbstractThis paper reports the development and testing of a rotary screw compressor lubricant based on two‐stage severely hydrotreated petroleum base oil, and compares the fluid's performance with that of a synthetic polyalphaolefinbased compressor fluid. It was found that performance was in most respects the same for both fluids. Laboratory and performance testing also shows equivalent extended service life greater than one year, with reduced maintenance and energy savings.
Influence of reinforcement and lubrication on abrasive wear performance of polyamide
Authors: Bijwe J. , Mathur J. N. , Tewari U. S. 
Published: July 2006

AbstractThis paper presents the results of studies on the wear performance of various composites of polyamide (nylon 6,6) reinforced with short carbon fibres and lubricated with a solid lubricant, PTFE, under adverse sliding conditions (abrasive wear). The effects of increasing amounts of fillers, fibre orientation, and experimental parameters such as load, and abrading particle size were investigated. The studies revealed that fillers that are very much suitable for adhesive wear applications are detrimental for the abrasive wear mode. Moreover, wear performance showed deterioration with increasing amount of filler concentration. The combination of heterogeneous fillers proved to be detrimental for wear performance. Efforts were made to correlate these investigations with appropriate mechanical properties. It was found that wear performance was greatly influenced by selected experimental parameters. Worn surfaces were examined with SEM to have better insight of the wear mechanism.
Environmentally considerate ester lubricants for the automotive and engineering industries
Authors: Randles S. J. 
Published: July 2006

AbstractConcern at the amount of lubricants lost in the environment has prompted the search for environmentally considerate lubricants, i.e. lubricants which biodegrade as a result of the biological action of living organisms. Various test procedures and parameters are discussed, and the performance of various lubricants, including synthetics, is presented.
Rheological properties of lithium, lithium complex, and sodium greases
Authors: Åkröm H. , Höglund E. 
Published: July 2006

AbstractThe rheological properties of two lithium, two lithium complex, and two sodium greases, all with the most common NLGI grade two, have been investigated. The greases are based on a mineral and a synthetic oil. The apparatus used was a cone‐and‐plate rheometer and an impacting‐ball apparatus.The impacting‐ball apparatus used a steel ball, which impacted a lubricated sintered carbide plate, to measure the shear stress‐pressure coefficient, γ, of the lubricant. At pressures found in elastohydrodynamic contacts this coefficient determined the limiting shear stress. The γ‐value thus affects the coefficient of friction and consequently, lower γ‐value means less friction.The results from the impacting‐ball apparatus showed that the γ‐value was lower for the greases with a synthetic base oil and that the lithium greases gave a lower γ‐value than the corresponding base oils.Results from the cone‐and‐plate rheometer showed the characteristic shear thinning behaviour of the greases and the influence of shear history and temperature. The results from the cone‐and‐plate rheometer have also been fitted to a four parameter rheological model.
A new high‐stability synthetic phosphate ester
Authors: Shankwalkar Sundeep G. , Placek Douglas G. 
Published: July 2006

AbstractNeutral phosphate esters are used as fire‐resistant basestocks in several applications including hydraulic systems, turbines, and compressors. They are also used as grease basestocks, and in hydrocarbon‐based lubricants and synthetic fluids as antiwear additives.Development aspects of a new synthetic triaryl phosphate ester is presented in this paper. This product provides superior hydrolytic stability and lower volatility than existing commercial phosphate esters. Additionally, it has excellent oxidative stability and is fire resistant. The performance characteristics of the fluid suggest use of this phosphate ester as a high stability antiwear additive or lubricant basestock, and in any application where stability is of primary importance.
Polymer‐polymer friction: Adhesion dependence
Authors: Lavielle L. , Lamouri S. 
Published: July 2006

AbstractThe friction of pure polyethylene and acrylate grafted films or mixtures of polyethylene and a poly (ethylene‐butylacrylate‐maleic anhydride) terpolymer is examined at low speed for sliding on a poly(methylmethacrylate)(PMMA) or polyvinylchloride (PVC) substrate. In all cases, the friction coefficient μ at equilibrium is proportional to the adhesion energy of the same films as determined by a peel test. This study shows how much for smooth surfaces, interfacial and mechanical properties intervene simultaneously in polymer‐polymer friction.
Role of synthetic esters in the overall performance of cold rolling oil for steel
Authors: Mahanti S. , Datta N. , Pandey N. , Barman S. , Maiti N. , Nambiar P. R. 
Published: July 2006

AbstractCold rolling mill productivity and product quality depend on the lubricant chemistry and composition, as well as on such physical factors as operation and maintenance. This paper discusses new requirements for rolling mill oils. Ester‐based rolling oil formulations have been developed and their performance is evaluated, notably in respect of lubricity, strip cleanliness, and emulsion stability. Changes in these properties during operation and storage are also considered. It is found that the properties are greatly influenced by chemical constitution and the fat‐to‐ester ratio.
Synthetics basics: Polyalphaolefins — base fluids for high‐performance lubricants
Authors: Benda R. , Bullen J. , Plomer A. 
Published: July 2006

AbstractPolyalphaolefins or PAOs are saturated oligomers manufactured via the catalytic oligomerisation of alphaolefins. An oligomeric mixture is obtained which is then hydrogenated and distilled to produce a range of PAOs. These synthetic fluids are differentiated and graded by their viscosities at 100°C. PAOs are mainly used as high‐performance functional base fluids in engine lubricants, gear oils, hydraulic oils, automatic transmission oils, compressor/pump oils, and greases.Automotive engine (crankcase) lubricants represent the biggest market for PAOs and here they compete with petroleum‐based oils. When compared to mineral oils, PAOs exhibit a number of inherently superior physical and chemical properties, such as greater fluidity at low temperature, lower volatility, a higher viscosity index, a lower pour point, better oxidative/thermal stability, low toxicity, and biodegradable low viscosity grades.This combination of properties means that PAOs enhance the formulator's ability to produce high‐performance lubricant oils. Some examples of performance benefits obtained from PAO‐based formulations have been shown to match and even exceed the performance of higher cost traditional ester‐based oils when tested under the new Japanese Automobile Standards Organisation (JASO) FC two‐stroke specifications. Low viscosity automotive engine oils, which can only be formulated with PAOs, can produce a fuel saving of >2% when tested under US Federal Test Procedure (USFTP) 75.
Thermal‐oxidative characteristics of some high‐temperature diesel lubricants
Authors: Li H. , Hsu S. M. , Wang J. C. 
Published: July 2006

AbstractMany advanced engine concepts require lubricants that function in a hightemperature environment. The thermal‐oxidative characteristics of some lubricants formulated for such purposes have been studied by a new thermogravimetric analysis (TGA) procedure. Factors affecting the stability of lubricants at elevated temperatures were incorporated into the experimental design. Information extracted from the TGA was able to provide insights into the thermal stability, oxidative stability, and oxidative volatility of lubricants. The merits of the technique were demonstrated by examining data obtained from engine tests simulating the operating conditions of the low‐heat‐rejection (LHR) engine. These engine test data confirmed that the NIST TGA is a useful tool in studying or formulating lubricants designed for high‐temperature applications.
High viscosity polymer esters as an alternative to PAO 100
Authors: Wallfahrer U. 
Published: July 2006

AbstractHigh viscosity polymer esters were studied as an alternative to PAO 100. High viscosity polyalphaolefins have the disadvantage of poor compatibility with additives. High viscosity polymer esters have now been developed which are compatible with polar and non‐polar elements. The properties of the base oils were tested, as were trial formulations of automotive gear oil and industrial gear oil.
A comparison of fire‐resistant hydraulic fluids for hazardous industrial environments. Part I. Fire resistance and lubrication properties
Authors: Phillips W. D. 
Published: July 2006

AbstractFire‐resistant hydraulic fluids have been developed since the Second World War. In addition to phosphate esters, there are various other fluids (e.g. oil‐in‐water emulsions, water glycols) available. This paper provides a technical comparison of the different fluid types, in terms of fire resistance, lubricating properties, and viscosity. The second part of the study examines the corrosion properties, thermal and oxidative stability, shear stability, materials compatibility, and other physical properties.
Investigation into the scuffing load capacity of environmentally‐friendly lubricating oils
Authors: Kozma M. 
Published: July 2006

AbstractThe present paper looks at the nature of scuffing, and the factors influencing it, for both hot scuffing and cold scuffing. The influence of surface layers and finishes in relation to this phenomenon are discussed, and some preliminary results are presented for cold scuffing tests, with various steels, for a mineral oil, a rapeseed oil, and a vegetable‐based oil.
A comparison of fire‐resistant hydraulic fluids for hazardous industrial environments. Part II. Stability, fluid life, and environment
Authors: Phillips W. D. 
Published: July 2006

AbstractFire‐resistant hydraulic fluids have been developed since the Second World War. In addition to phosphate esters, there are various other fluids (e.g. oil‐in‐water emulsions, water glycols) available. This paper provides a technical comparison of the different fluid types, in terms of fire resistance, lubricating properties, and viscosity. The second part of the study examines the corrosion properties, thermal and oxidative stability, shear stability, materials compatibility, and other physical properties.
Gas chromatography with an atomic emission detector for turbine engine lubricant analysis
Authors: Keller Michael A. , Saba Costandy S. 
Published: July 2006

AbstractLubricants and/or additives may need characterisation, or detection of contaminants and their identification. Analysis of turbine engine lubricants using Gas Chromatography with an Atomic Emission Detector (GC‐AED) is shown to be a function of the versatility of its multi‐element detection ability, and to offer advantages over previously used chromatographic detectors. GC‐AED can reveal identity of elements, and this paper presents GC‐AED results for MIL‐L‐7808 turbine‐engine lubricants, and for some thermally stable hightemperature candidate organic compounds — polyphenyl ether, phenyl thioethers, and cyclotriphosphazenes.
Cram be abyssinica oil and its derivatives as renewable lubricants: Synthesis and characterisation of different esters based on crambe fatty acids
Authors: Bondioli P. , Inzaghi L. , Postorino G. , Quartuccio P. 
Published: July 2006

AbstractThe authors have studied the possibility of using Crambe abyssinica oil as a starting material for synthetic lubricants, and in this paper the procedures for the preparation of monoesters from methyl, ethyl, isopropyl, and 2‐ethylhexyl alcohol, as well as diesters from neopentylglycol, triesters from trimethylolpropane and tetraesters from pentaerythritol, are described. The different reactions were set up using free fatty acids, methyl esters, and Crambe oil as starting materials. All reactions were carried out in a solvent‐free medium, using normally available catalysts and under experimental conditions which could easily be scaled up to industrial level. All the products obtained, along with the refined Crambe abyssinica oil used as a reference, were analysed for viscosity, viscosity index, low‐temperature behaviour and oxidative and hydrolytic stability. Results of tests, such as four‐ball machine and Noack, are reported. The results show that several products covering a wide range of different applications can be obtained from the basic Crambe abyssinica oil, and, furthermore, the chemical modification of the Crambe abyssinica oil can, in some cases, improve thermal and hydrolytic sensitivity and even the tribological properties.