bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of temperature on the friction and wear of heat‐resistant polymer‐based composites
Authors: Tanaka Kyuichiro , Yamada Yoshinori , Ueda Seiichi 
Published: July 2006

AbstractThe friction and wear of polyether sulphone (PES: ‘Victrex’‐ICI), polyether etherketone (PEEK: ICI), polyamide‐imide (PAI: Torlon'‐Amoco) and Polytetrafluoroethylene (PTFE) composites were measured at a constant sliding speed and under a constant load at various temperatures up to 300 °C by rubbing against a steel disc. The frictions of the composites, except for some PAI composites, were generally little dependent upon temperature over a wide range of temperature. PTFE filler was effective in reducing the wear of composites at high temperatures. However, the addition of various fibres to the composites was not effective at high temperatures. The wear of PAI composites increased rapidly with increasing temperature and thus their temperature variations were considerably greater than those of the other composites. The wear of PTFE containing ‘Econol’ E–1 OI, a polyoxybenzylene nomo‐polymer (Sumitomo Chemical Co.) and graphite was similar to that of the PEEK composite containing PTFE, and their wear rates were remarkably low over a wide range of temperature. The wear‐reducing mechanisms of PTFE and ‘Econol’ fillers are discussed on the basis of microscopic examinations of the frictional surfaces.
Some experimental studies of lubricants in a two‐stroke methanol engine
Authors: Chadha B. R. , Gupta Mukesh , Gupta L. R. , Maji S. , Singhal S. 
Published: July 2006

AbstractA two‐stroke cycle scooter engine modified to operate on methanol fuel has been tested. Castor and synthetic oil formulations were identified as potential lubricants. A formulation based on polypropylene glycol (PPG) has demonstrated excellent miscibility in methanol fuel. It also performed well in engine tests, especially with reference to piston tightening and deposit forming tendencies.
A mechanism of thermo‐oxidative degradation of polyol ester lubricants
Authors: Bakunin V. N. , Parenago O. P. 
Published: July 2006

AbstractPolyol ester lubricants are used in a wide range of temperature conditions, normally from −54 up to +220 °C, and their application can be limited by high temperature oxidation leading to viscosity increase, sludge, and/or formation of deposits. This paper is concerned with the chemical processes which take place during the oxidation of esters, particularly polyol esters, and discusses the selectivity of oxygen attack on ester molecules, and the formation and decomposition of hydroperoxides as well as other products formed as a result of ester oxidation. Proposed mechanisms of polyol ester lubricant oxidation are discussed, and unresolved problems which require additional research efforts are revealed.
Perfluoropolyether lubricants
Authors: Corti C. , Savelli P. 
Published: July 2006

AbstractThis work reports the physico‐chemical characteristics, the tribological characteristics and additive susceptibility of two series of perfluoropolyether fluids and greases, one obtained from hexafluoropropene, the other from tetrafluoroethene. Some applications of perfluoropolyether lubricants are considered.
Testing, application, and future development of environmentally friendly ester base fluids
Authors: van der Waal G. , Kenbeek D. 
Published: July 2006

AbstractBiodegradation test methods have been compared with regard to test conditions and test parameters. It has been shown that three methods are, in principle, suitable for non‐water soluble products. These are the Sturm test (OECD no. 301B), the MITI test (OECD 301 C), and the CEC L‐33‐T‐82 test method. A comparison in an actual test showed that the CEC test gives the highest biodegradation values, while the Sturm test and the MITI test give lower values. It is noted that the CEC test measures the amount of material used for both energy production and growth of the biomass, while the other methods measure only the material used for energy production. A possible explanation for the difference between the Sturm and the MITI test results is given. The CEC test is shown to be more suitable for the lubricant industry. Applications of biodegradable lubricants are reviewed, particularly hydraulic fluids. It is shown that rape seed oil (natural ester) and synthetic polyol esters have similarities regarding structure but also significant differences. This results in much better thermal and oxidative stability for the synthetic esters. These also offer the possibility of making a range of products of different ISO grades with similar properties.Brief consideration is given to future potential, notably for biodegradable four‐stroke lubricants. Finally, there is a timely reminder that, owing to the present limited availability of natural oils and fats and their cost, only 19% of the market for mineral oil base fluids could be replaced by natural oils and fats and their derivatives.
Magnetic fluids in sealing and lubrication – a state of the art review
Authors: Säynätjoki M. , Holmberg K. 
Published: July 2006

AbstractThe paper is a review of the properties and functions of magnetic fluids and their potential use in tribological applications, such as seals and bearings. They offer new possibilities for achieving low friction, low wear, and no leak‐ age.Magnetic fluids or ferrofluids consist of magnetic particles suspended in a carrier fluid and a coating on the particles. The coating prevents the agglomeration of the particles through magnetic and molecular attraction by keeping the distance between them sufficiently large. The magnetic fluids have the basic properties of liquids and they act like ferromagnetic materials in the presence of an external magnetic field.Shaft sealing is the most promising potential application for ferrofluids. Magnetic seals have zero‐leakage and low friction, they are non‐stick and they have high‐performance properties. Lubrication is another important application of ferrofluids. The advantage over conventional lubricants is the possibility of keeping the lubricant exactly and only where it is needed. They provide the possibility of increasing the life of components. Furthermore, because they do not contaminate, ferrofluids are also used as lubricants in clean environments.
A polyalphaolefin with exceptional low‐temperature properties
Authors: Theriot K. J. , Shubki R. L. 
Published: July 2006

AbstractA new process has been discovered for the production of low‐viscosity PAO fluids in high yield. In particular, the new process can be used to produce a mixture of decene dimers that has low‐temperature properties which are superior to the properties of decene dimers produced by the conventional PAO process.
Soluble additives for perfluorinated lubricants
Authors: Srinivasan P. , Corti C. , Montagna L. , Savelli P. 
Published: July 2006

AbstractHigh‐performance aerospace systems make severe demands on lubricants. Among the potential candidates, perfluorinated fluids, especially perfluoropolyethers (PFPEs), lead the list. PFPEs are unique in that several of the properties required for the lubrication of these systems, such as thermalloxidation stability, chemical inertness, compatibility with materials of construction, high viscosity index, etc., are inherent to them. However, there is a need to add other characteristics or to improve some of the inherent properties. Research programme to find a solution by preparing PFPEs with different structures as well as developing soluble anticorrosion, antiwear, and stabilising additives has been undertaken. The present paper describes the preliminary results obtained with a few additives and suggests possible action mechanisms.
Effect of testing conditions on friction and wear of a polyetheretherketone‐based composite
Authors: Guo Qiang , Friedrich Klaus 
Published: July 2006

AbstractFriction and wear characteristics of a type of polyetheretherketone (PEEK)‐ based composite were evaluated under two different loading pressures and sliding speeds (P = 1.0 MPa, V = 1.0 m/s and P=2.0 Mpa, V=3.3 m/s). The material was in contact with steel surfaces of two different roughnesses (Ra=0.15 μm and Ra=0.33 μm). Interface temperature, coefficient offriction, depth wear rate, and specific wear rate of the polymer composite changed considerably with the PV value and the counterface roughness. The interface temperature increased with increasing PV value, whereas the friction coefficient decreased. The depth wear rate at the higher PV value was much higher than that at lower PV. In addition, the rougher counterface resulted in a higher friction coefficient, depth wear rate, and specific wear rate, when the PV value was fixed. The effect of counterface roughness on the specific wear rate at the higher PV value was smaller than that at the lower PV. Further variations in friction and wear with testing conditions are discussed along with the corresponding microscopic observations of the worn polymer surfaces and the polymer transferred counterfaces.
Use of a non‐conventional synthetic basestock in the formulation of high‐quality engine oils
Authors: Fisicaro G. , Fattori S. 
Published: July 2006

AbstractResearch has been undertaken to identify new synthetic basestocks, to be used alone or with polyalphaolefins, for the formulation of high‐quality engine oils.Basestock selection was limited to products not normally used in the synthesis of ester‐type basestocks. A non‐conventional product was identified: a carbonic ester of synthetic alcohols. A complete engine oil has been formulated using this basestock and submitted to a full test programme. The results are reported.
Low pour point polyalkyl benzene oils for refrigeration compressors
Authors: Cvengroš Ján , Faberová Anna , Lazar Ľubomír 
Published: July 2006

AbstractIn this paper, the results of fractionation of polyalkyl benzene residues from monoalkyl benzene production, using a molecular evaporator to obtain fractions which are usable as lubrication oils for refrigeration compressors with a non‐polar refrigerant, are presented. Two of the distillion fractions pre‐pared correspond to international viscosity classes I S 0 VG 22 and 46. Their yields of 45 and 15% respectively from the original residues are economically interesting and they are of a higher quality than the previously used mineral oil based lubricants. The polyalkyl benzenes have improved properties, such as viscosity index, flash point temperature, and pour point. The lower thermo‐oxidative stability of the fractions is compensated for formulations with appropriate antioxidants.
Synthetic fluids between synthetic hydrocarbons and ester fluids: Co‐oligomers of alphaolefins and alkylmethacrylates
Authors: Jelitte Rüdiger , Beyer Claudia 
Published: July 2006

AbstractThrough co‐oligomerisation of alphaolefins with alkylmethacrylates, fluids are obtained with a unique chemical combination of non‐polar PAO and polar ester oil in one molecule. The polarity of these co‐oligomers between P A 0 on the one hand and ester oil on the other helps to avoid the typical disadvantages of these common synthetic base oils. Thus, co‐oligomers offer superior solvency for DI packages, neutral elastomer behaviour, the hydrolytic stability of sterically hindered esters, a thermal and oxidative stability close to PAO, and free miscibility with mineral oil and synthetic base stocks. Co‐oligomers are Newtonian fluids of high purity and with a viscosity range between 50 and 600 mm2/s at 100°C. Both viscosity level and purity open up a range of applications. Even without high molecular weight VI improver, gear oils, and hydraulic oils with outstanding viscometric performance can be formulated. The purity has a positive influence on properties such as demulsibility, de‐aeration, and foaming behaviour. The present paper compares co‐oligomers with common base fluids and gives examples of typical applications.
Tribological characteristics of Perfluoropolyether liquid lubricants under sliding conditions in high vacuum
Authors: Masuko Masabumi , Jones William R. , Helmick Larry S. 
Published: July 2006

AbstractTribological characteristics of three PFPEs (Fomblin Z, Demnum, and Krytox) were studied under high vacuum using a four‐ball apparatus with 440C steel specimens. Fomblin Z and Demnum exhibited initial scuffing‐like high friction whereas Krytox did not. Steady state friction with Fomblin Z was the lowest among the three oils and that with Demnum and Krytox was almost the same. The lowest wear rates in air were provided by Krytox regardless of load and low wear rates in vacuum at high load were achieved with Krytox and Demnum. Results are explained by reactivity and pressure‐viscosity characteristics of the oils.
Improvement of the wear behaviour of the couple UHMWPE–Ti6A14V through surface treatments
Authors: Martinella R. , Giovanardi S. , Palombarini Lg. , Giorgi R. 
Published: July 2006

AbstractOwing to the great interest in the medical field in the tribological couple UHMWPE–Ti6Al4V, its wear behaviour was studied and compared to that displayed by the more typical couples of UHMWPE–AISI 316 and UHMWPE–Vitallium.The Ti6Al4V alloy was given three different surface treatments: (a) a conventional lapping procedure; (b) a special lapping procedure; (c) nitrogen ion‐implantation at 873°K. The last two samples induced, on a UHMWPE countetace, a wear rate lower than a factor of 10 compared to diamond lapped specimens; their behaviour was also better than the couples UHMWPE–AISI and UHMWPE–Vitallium.Wear improvement was attributed to the reduction of polymer transfer and adhesion on the metal counterface, due to the reduction of adhesive affinity between UHMWPE and the metal following surface treatment of the metal. The results are interpreted on the grounds of TEM and AES analyses.
Performance testing of lubricants based on high oleic vegetable oils
Authors: Lal Kasturi , Carrick Virginia 
Published: July 2006

AbstractOwing to growing environmental concerns, vegetable oils are finding their way into lubricants for industrial and transportation applications. Vegetable oils can of Ser significant environmental advantages with respect to resource renewability and biodegradability, as well as offering satisfactory performance in a variety of applications. Synthetic ester‐based fluids may also offer these advantages, however their cost can be prohibitively high. Formulating with vegetable oil does, however, present unique challenges. These are, most notably, the oxidative and hydrolytic instability and low temperature problems associated with the triglyceride. However, through advanced plant breeding techniques, vegetable oils are becoming available which exhibit excellent thermal and oxidative stability and other improved performance properties. The cost of these oils is much lower than synthetic esters, thereby making them attractive ‘environmental’ base fluids.
Biodegradability and toxicity of polyalphaolefin base stocks
Authors: Carpenter Joel F. 
Published: July 2006

AbstractLow viscosity polyalphaolefin fluids (2 and 4 cSt ® 100°C) are significantly biodegraded under the conditions of the CEC‐L‐33‐T‐82 test procedure. This is contrary to the widespread, but inaccurate, perception that polyalphaolefin (PAO)fluids are generally not biodegradable. In a time‐extended CEC‐L‐33‐T‐82 test, the 2, 4, and 8 cSt fluids were shown to continue biodegrading well past the 21 ‐day span prescribed in the standard method. PAO fluids are considered non‐toxic and non‐irritating to mammals. Moreover, they are not expected to be toxic to aquatic organisms: in the Microtox® test with bioluminescent bacteria, no observable effects were detected for concentrations of 49,500 ppm of the water‐soluble fraction.
Thermo‐oxidative behaviour of perfluoropolyalkylethers
Authors: Koch B. , Jantzen E. 
Published: July 2006

AbstractFor high‐temperature aircraft turbine engines in the next century, new, extremely stable lubricants will be required. The chemical class known as perfluoropolyalkylethers is well known for its good and wide range of temperature behaviour. This paper reports on investigations into the thermo‐oxidative stability of these fluids at high temperatures. The work includes the influence of metals on the stability, and corrosion tests, of selected PFPAE oils. The results show the large influence of the chemical structure and of certain metals.
Die‐less wire drawing using polymer fluids
Authors: Symmons G. R. , Stokes M. R. 
Published: July 2006

AbstractA die‐less wire drawing process has been developed in order to investigate the performance on the reduction of wire size of polymer coating on steel wire. Previous experimental investigations have shown significant reductions in area particularly using nylon and borosiloxane on copper wire. The present investigation shows that satisfactory reductions can also be obtained using these polymers on steel wire. A smooth adhered coating of the wire was produced with the nylon; however, drawing speed limitations were observed where break up of the coatings occurred.
Biodegradable lubricants — Analysis of metalworking oils and hydraulic fluids by mass spectroscopy
Authors: Zeman Alfred 
Published: July 2006

AbstractBiodegradable metalworking oils and hydraulic fluids were screened for their base oil composition using a special mass spectrometric technique — direct exposure probe chemical ionisation mass spectrometry (CI(NH3)‐MS). All but one of the hydraulic fluid samples were rapeseed oil or trimethylolpropane trioleate based, the other sample being a neopentylglycol ester trimethylolpropane ester mixture. Ethylhexyl ester of rapeseed oil fatty acids (or similar) was present in some of the metalworking fluids in addition to rapeseed oil, whilst other samples were pure rapeseed oil. In several cases a trimethylolpropane/neopentylglycol ester base was found. Preliminary results for additive isolation/identification show the usefulness of preparative gel permeation chromatography.
Evaluation of potassium trifluoroacetylacetonate as a synergist for arylamine antioxidant in synthetic lubricants
Authors: Yao Junbin , Dong Junxiu 
Published: July 2006

AbstractDifferential scanning calorimetry (DSC) was employed to evaluate the performance of an ester lubricant containing potassium trifluoroacetylacetonate. In the isothermal DSC oxidation test, potassium trifluoroacetylacetonate is an effective synergist for arylamine antioxidants such as p, p'‐dioctyldiphenylamine (DODPA). In combining with arylamine antioxidants, potassium trifluoroacetylacetonate can also effectively reduce the increase in viscosity and acid number of the ester oil in oxidation‐corrosion tests. The electron paramagnetic resonance (EPR) results indicated that potassium trifluoroacetylacetonate can reduce the free radical content in the oxidised oil when arylamine antioxidants are present.
Sulphurised vegetable oils as EP additives for industrial gear oil formulations
Authors: Bisht R. P. S. , Bhatia V. K. 
Published: July 2006

AbstractRenewable sources can provide, besides fuel, a wide range of feed stocks for the organic chemicals industry. Utilisation of non‐edible vegetable oils and speciality chemicals has, therefore, become relevant in recent times. Sulphurisation of three triglyceride oils (karanja, rapeseed, and castor oils) and liquid wax (jojoba) has been investigated in detail in order to examine the potential of sulphurised vegetable oils for use as extreme‐pressure (EP) additives for developing formulations for industrial gear oils. The capacity of these oils with respect to the uptake of sulphur, the limitations of some of the sulphurised products for use as EP additives, and the problems in developing such formulations for industrial gear oils, are discussed.
Development of ecologically responsive lubricants
Authors: Adamczewska J. Z. , Wilson D. 
Published: July 2006

AbstractAs a result of growing environmental concerns, vegetable oils are finding their way into lubricants for both industrial and transportation applications. These oils can offer significant environmental advantages with respect to resource renewability and biodegradability, as well as offering satisfactory performance in various applications. Formulating with vegetable oils does, however, present unique challenges. These are, most notably, the oxidative and hydrolytic instability, and low temperature rheological problems associated with triglycerides. However, through advanced plant breeding techniques, vegetable oils are becoming available which exhibit good thermal and oxidative stability and other improved performance properties. An overview comparing the physical and chemical characteristics of vegetable oils with those of mineral oils, with particular emphasis on their oxidative stability and wear performance, is presented. Development of lubricant formulations for, in particular, farm tractors and hydraulic fluids, using combinations of vegetable oils and additives, will be discussed in comparison with field trial data.
The optical EHD method applied to the study of ageing of biodegradable oils
Authors: Cloesen C. , Kabuya A. , Bozet J. L. 
Published: July 2006

AbstractIn the present study, modifications of the lubricating properties of vegetable oils, which had undergone accelerated ageing, were quantified, using the optical EHD method. Each oil sample was examined in an optical viscometer in order to measure film thickness vs. contact speed. From these results the pressure—viscosity coefficient was calculated, by adjusting theoretical values. The modifications were related to molecular changes, which were observed with various tools of chemical analysis, including gel permeation chromatography (GPC).
Determination of spontaneous ignition temperatures of ester‐based aviation lubricants using pressure differential scanning calorimetry (PDSC)
Authors: Basken A. , Zeman A. , Maier K. 
Published: July 2006

AbstractThe usefulness of pressure differential scanning calorimetry (PDSC) in the determination of spontaneous ignition temperatures (SITs) of newly developed ester‐based aviation turbine engine oils is shown. Data on the reproducibility of measurements on aluminium and steel surfaces is given.
Lubricant components from vegetable oils of indian origin
Authors: Anand O. N. , Mehta J. , Prasada T. S. R. Rao 
Published: July 2006

AbstractA number of transesterified and alkarylated derivatives have been synthesised from available vegetable oils of Indian origin. The viscosity, viscosity index, freezing points, load‐carrying characteristics, friction coefficient, and thermo‐oxidative stability of these derivatives as compared to highly refined hydrorefined hydrocarbon oils have been studied.It has been found that several esters of fatty acids of these vegetable oils have a high natural viscosity index, low pour points, and high thermooxidative stability, and can meet the requirements as base fluid components for energy‐efficient, eco‐friendly, long‐drain interval, multigrade oils. These oils have markedly lower viscosities at 40°C, higher load‐carrying characteristics, and lower friction coefficients than the base fluids of currently marketed multigrade oils. A 50% blend with hydrorefined hydrocarbon oils could prove highly viable.The above results clearly establish the potential for utilising these esters, either alone, or in combination with mineral oils, for formulating cost‐effective high‐performance, energy‐efficient, and environmentally friendly lubricants. Performance characteristics of these oils as engine oils, automotive gear oils, and 2 stroke oil with conventional additives and with alternative additives are under investigation in comparison to the most advanced hydrocarbon based multigrade oil formulations of long‐drain interval.