摘要:

AbstractThree commercially available hydraulic/transmission lubricants based on rapeseed oil have been investigated for their lubricating properties. The coefficient of friction, scuffing‐load capacity, and pitting resistance were evaluated, and the results compared with a corresponding commercial mineral‐based oil.The results showed in general a substantially lower coefficient of friction and better pitting resistance for rapeseed‐based oils than for the mineral oil. Scuffing load capacity was, with one exception, the same for all oils. As a result of lower shear stresses during contact, and a higher viscosity index, the temperatures in the gearbox were lower for the rapeseed oils tested than for the mineral oil. Insufficient antiwear behaviour at high loads was found to be a major drawback of these vegetable

ISSN:0265-6582    

DOI:10.1002/jsl.3000160402

出版商:John Wiley&Sons, Ltd    

年代:2000

数据来源: WILEY

摘要:

AbstractThis paper looks in detail at hydrolysis of esters. While this is not normally a problem, hydrolytic stability can be an important consideration, e.g., in air compressors. The paper looks first at the synthesis of esters, which is a reversible reaction of acid + alcohol ↔ ester + water, usually involving a catalyst. Two mechanisms of ester hydrolysis, namely base‐catalysed and acid‐catalysed, are described as being most relevant to lubricant esters, the former being less likely than the latter. Two extended tests are described which have been used in the author's laboratory, a beverage‐bottle test (modified ASTM D‐2619), and a sealed‐tube test, for hydrolytic measurement. The paper goes on to look in detail at the effect of ester structure on rate of hydrolysis, in terms of resonance effects and steric effects, on the effect of impurities, and of acidic and acid catche

ISSN:0265-6582    

DOI:10.1002/jsl.3000160403

出版商:John Wiley&Sons, Ltd    

年代:2000

数据来源: WILEY

摘要:

AbstractPolyglycols are used in a wide range of applications, including lubrication. Many advantageous properties can be obtained for lubricant applications by manipulating the four variables in polyglycol preparation: the initiator, the alkylene oxides, the molecular build‐up, and the mole weight. However, it has long been believed that it would not be possible to combine these properties with a good environmental profile of high biodegradability and low aqueous toxicity. Development work at the authors' laboratory has resulted in polyglycol‐chemistry‐based products that fulfil the application requirements and are also environmentally friendly. Assessment by the Umwelt Bundes Amt has led to a statement of suitability for Blue Angel formulations for two water‐soluble polyglycol grades (ISO 22 and IS0 46). Environmentally‐friendly watersoluble polyglycol base stocks currently includes the range ISO 10 to ISO 100. The development of environmentally friendly water‐insoluble and oil‐soluble polyglycols

ISSN:0265-6582    

DOI:10.1002/jsl.3000160404

出版商:John Wiley&Sons, Ltd    

年代:2000

数据来源: WILEY

摘要:

AbstractThis paper reports on some work concerned with the synthesis and characterisation of three lubricating greases based on animal bone fat, cottonseed soapstock, and a mixture of them both. The physico‐chemical properties of these fats were established and showed them to be good thickeners in the preparation of different types of greases. It was shown that the growth of the soap structure and grease consistency depend on the type of fat as well as on the viscosity of the lubricating oil in the grease formulation. The greases so synthesised were assessed in accordance with standard NLGI grades and Egyptian standards. Their rheological and thermal behaviour was studied, which revealed that the synthesised greases have significant yield stress at normal operating temperature and good flow properties. It was concluded that the above mentioned fat by‐products are suitable for producing grea

ISSN:0265-6582    

DOI:10.1002/jsl.3000160405

出版商:John Wiley&Sons, Ltd    

年代:2000

数据来源: WILEY

摘要:

AbstractA brief review of the oils, fuels, additives, and other industrial products being derived from non‐food crops in France, and the potential market for the

ISSN:0265-6582    

DOI:10.1002/jsl.3000160406

出版商:John Wiley&Sons, Ltd    

年代:2000

数据来源: WILEY

ISSN:0265-6582    

DOI:10.1002/jsl.3000160407

出版商:John Wiley&Sons, Ltd    

年代:2000

数据来源: WILEY

ISSN:0265-6582    

DOI:10.1002/jsl.3000160408

出版商:John Wiley&Sons, Ltd    

年代:2000

数据来源: WILEY

ISSN:0265-6582    

DOI:10.1002/jsl.3000160409

出版商:John Wiley&Sons, Ltd    

年代:2000

数据来源: WILEY

ISSN:0265-6582    

DOI:10.1002/jsl.3000160401

出版商:John Wiley&Sons, Ltd    

年代:2000

数据来源: WILEY