ISSN:0265-6582    

DOI:10.1002/jsl.3000170102

出版商:John Wiley&Sons, Ltd    

年代:2000

数据来源: WILEY

摘要:

AbstractThe film thicknesses of two polyolester degraded oils were measured over a wide range of temperatures to investigate the influence of degradation on film‐forming properties. The results have been interpreted in the light of the idea that degradation of an ester lubricant can produce two different types of product which have opposing influences on film‐forming properties. One is the formation of smaller, polar molecules, such as acids, which may result in a decrease in effective pressure—viscosity coefficient. The other is the formation of larger, bulky molecules such as sludge, which result in increased pressure—viscosity coefficient. The effective pressure—viscosity coefficient decrease with degradation of the oil thus is made up of an earlier stage involving a series of reactions, followed in a later stage by an

ISSN:0265-6582    

DOI:10.1002/jsl.3000170103

出版商:John Wiley&Sons, Ltd    

年代:2000

数据来源: WILEY

摘要:

AbstractThe aim of the present work was to produce inexpensive synthetic lubricants, compatible with R‐134a, using waste carboxylic acids as the starting point. After initial synthesisation of some candidate materials, the suitability of the synthesised products was first evaluated by their chemical and physical properties including thermostability. Two ester bases were selected for further testing — a pentaerythritol esterified with monocarboxylic acids, and a polyalkyleneglycol similarly esterified with monocarboxylic acids C4—C6. The oil bases selected were tested for their corrosion effect on metals. The pentaerythritol ester offered the most advantageous properties in these tests. The results of the laboratory tests have been corroborated by trials conducted on real refrigerating compressor systems. In addition, the synthesis of base oils by methyl ester transesterification in the presence of basic catalysts has been exa

ISSN:0265-6582    

DOI:10.1002/jsl.3000170104

出版商:John Wiley&Sons, Ltd    

年代:2000

数据来源: WILEY

摘要:

AbstractThe present paper deals with the synthesis of some tetraesters with a mixed structure of pyromellitic dianhydride, and with their characterisation as potential base oils. These esters are made on the basis of a long branched aliphatic alcohol, such as isotridecanol, and an alcohol with aromatic content, such as 2‐phenoxy‐ethanol. The variation of the principal properties as a function of both the length of the aliphatic chain introduced by the aliphatic alcohol, and the aromatic content introduced by the aryl‐alkyl alcohol has been assessed and the potential for viable products with a wide range of viscosity values has been examined. The enhanced aryl content is shown to induce superior thermal behaviour. These products present good test results and, thereby, demonstrate their versat

ISSN:0265-6582    

DOI:10.1002/jsl.3000170105

出版商:John Wiley&Sons, Ltd    

年代:2000

数据来源: WILEY

摘要:

AbstractIn this paper, the results of a characterisation of heavy alkylated benzenes (HAB) using multipulse NMR spectroscopy are presented. Four commercial samples of heavy alkylated benzene have been characterised in detail in terms of various structural parameters, such as percentage aromatic carbon (Ca), degree of aromatic substitution, average alkyl chain length, type of alkyl chain and their proportions. Three of the HAB samples were very similar in structure, whereas, in the fourth, the structures present were entirely different. The latter had an abundance of 2‐phenyl alkane‐type structures, and did not contain methyl substituted tetralin or naphthalene type molecules. The influence of the structures on lubricating oil properties, including viscosity index, pour point, and viscosity, as well as FreonTMfloc point, are also discus

ISSN:0265-6582    

DOI:10.1002/jsl.3000170106

出版商:John Wiley&Sons, Ltd    

年代:2000

数据来源: WILEY

摘要:

AbstractThis paper reports on work by the authors to develop a series of heterocyclic compounds for use in turbine aviation oils as antioxidant and anticorrosion additives. First, the new compounds were synthesised, and twenty‐eight candidate additives were developed. These were tested for their antioxidant and anticorrosion properties, and from these results three were found to exhibit better behaviour than the others. These three were then tested against DODPA, an existing aviation fluid additive, and were found to offer comparable behaviour in initial test

ISSN:0265-6582    

DOI:10.1002/jsl.3000170107

出版商:John Wiley&Sons, Ltd    

年代:2000

数据来源: WILEY

ISSN:0265-6582    

DOI:10.1002/jsl.3000170108

出版商:John Wiley&Sons, Ltd    

年代:2000

数据来源: WILEY

ISSN:0265-6582    

DOI:10.1002/jsl.3000170109

出版商:John Wiley&Sons, Ltd    

年代:2000

数据来源: WILEY

ISSN:0265-6582    

DOI:10.1002/jsl.3000170110

出版商:John Wiley&Sons, Ltd    

年代:2000

数据来源: WILEY

ISSN:0265-6582    

DOI:10.1002/jsl.3000170101

出版商:John Wiley&Sons, Ltd    

年代:2000

数据来源: WILEY