摘要:

AbstractUsing dimethyl adipate, dimethyl sebacate, and neopentyl glycol as starting materials, oligomeric esters with different ranges of molecular mass were synthesised. The transesterification reactions were catalysed with calcium methoxide. The esters have the physicochemical properties appropriate for use as synthetic lubricants. Both the adipic acid esters and sebacic acid esters are characterised by high biodegradability. The esters studied are considered to be environmentally friendly high‐performance functional fluid

ISSN:0265-6582    

DOI:10.1002/jsl.3000200202

出版商:John Wiley&Sons, Ltd    

年代:2003

数据来源: WILEY

摘要:

AbstractThe physical and chemical properties for a series of structurally well‐defined, alkylated naphthalenes have been compared. Structural characteristics, such as the alkyl chain length, alkyl chain branching, and number of alkyl groups on the naphthalene ring, have been correlated with physical properties, such as viscosity, viscosity index, pour point, and aniline point. The thermo‐oxidative stability of the alkylated naphthalenes was evaluated by the rotating pressure vessel oxidation test (RPVOT), a bulk oxidation test (BOT), and pressure differential scanning calorimetry (PDSC). Although all of the alkylated naphthalenes showed better thermo‐oxidative stability than other traditional hydrocarbon‐based fluids, the relative performance of the structurally different alkylated naphthalenes was found to be test dependent. Initial RPVOT studies with a linear polyalkylated naphthalene show that it gives good additive response to the incorporation of traditional antio

ISSN:0265-6582    

DOI:10.1002/jsl.3000200203

出版商:John Wiley&Sons, Ltd    

年代:2003

数据来源: WILEY

摘要:

AbstractThe main advantages of lubricants based on synthetic esters are their good biodegradability and low toxicity. Most of them are classified as non‐water polluting. Also, the lubricants should be stable for a long time, while operating under varying conditions. In the work presented here ‐ part of a research projectSFB 442, University of Aachen, see acknowledgement.to improve the ecological and technical properties of these types of lubricant by chemical modification of the base fluids, variation of the type and concentration of additives, and application of new coating technologies for tools with which the lubricants are used ‐ the effects of different operating conditions on toxicity, biodegradability, and chemical characteristics are assessed using biological and chemical methods. Water‐extractable toxicity is determined using a modified extraction technique and several bioassays, which allow one to distinguish between the toxic potential of the base fluids and that of the base fluids with additives. Biodegradability is determined using an optimised test system, changes in the chemical composition of the lubricants are quantified, and it is shown how the addition of additives, and the changes in the lubricants during use, affect the ecological characte

ISSN:0265-6582    

DOI:10.1002/jsl.3000200204

出版商:John Wiley&Sons, Ltd    

年代:2003

数据来源: WILEY

摘要:

AbstractIn Parti I the results of an extensive experimental investigation of the performance of environmentally adapted oils in the hydrodynamic regime were reported. Four oils were tested in a tilting‐pad thrust bearing for different combinations of load, shaft speed, and supply oil temperature. In this second part, details of a generalisation procedure are described. A number of parameters representing the physical properties of an oil, such as viscosity and viscosity‐temperature coefficient, are adopted. The influence of each of these parameters on minimum oil film thickness, maximum temperature rise, and bearing power loss is then analysed. It is shown that viscosity measured at the supply oil temperature is the most important parameter. The effects of the viscosity‐temperature coefficient and oil thermal conductivity are less pronounced and yet significant. It is also shown that it is not possible to select an optimum oil that yields maximised oil film thickness, minimised temperature rise, and minimised power loss at the same

ISSN:0265-6582    

DOI:10.1002/jsl.3000200205

出版商:John Wiley&Sons, Ltd    

年代:2003

数据来源: WILEY

摘要:

AbstractWith the growing concern about environmental pollution, vegetable oils have begun to be applied as base oils for environmentally friendly lubricants. Additives containing phosphorus can be used for their excellent antiwear properties and low toxicity. In view of this, a study of a series of phosphate esters as additives in rape seed oil (RSO) was carried out using a four‐ball tester. The results indicate that phosphate esters possess very good load‐carrying capacity and good antiwear and friction‐reducing properties compared with RSO by itself. Surface analysis of the worn balls was carried out using X‐ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The tribological mechanism of the additives is discussed on the basis of the experimental

ISSN:0265-6582    

DOI:10.1002/jsl.3000200206

出版商:John Wiley&Sons, Ltd    

年代:2003

数据来源: WILEY

ISSN:0265-6582    

DOI:10.1002/jsl.3000200207

出版商:John Wiley&Sons, Ltd    

年代:2003

数据来源: WILEY

ISSN:0265-6582    

DOI:10.1002/jsl.3000200208

出版商:John Wiley&Sons, Ltd    

年代:2003

数据来源: WILEY

ISSN:0265-6582    

DOI:10.1002/jsl.3000200209

出版商:John Wiley&Sons, Ltd    

年代:2003

数据来源: WILEY

ISSN:0265-6582    

DOI:10.1002/jsl.3000200201

出版商:John Wiley&Sons, Ltd    

年代:2003

数据来源: WILEY