摘要:

AbstractThe main products of the thermal‐oxidative degradation of p, p'‐di‐tert‐ octyldiphenylamine, phenothiazine and 3,7‐di‐tert‐octylphenothiazine (DODPA/PTZ/DOPTZ) in pentaerythritol ester at 200°C were isolated and identified. Recombination o f aminyl radicals giving various dehydrodimers and dehydro‐trimers is obviously the dominating reaction in the primary stage of antioxidant depletion during ageing of inhibited ester oils. Minor degradation products include quinone imines, quinones, sulphoxides, phenoxazine and phenoxazone derivatives. Because of the complexity of the reactions product analyses are inevi

ISSN:0265-6582    

DOI:10.1002/jsl.3000040302

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

摘要:

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.

ISSN:0265-6582    

DOI:10.1002/jsl.3000040303

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractPolyphenylene sulphide is a polymer with good thermal stability and high crystallinity. This paper summarizes the results of friction and wear studies of polyphenylene sulphide and its composites made with conventional solid lubricants to ascertain the suitability of the material as a matrix for solid lubricant additives. The polymer itself has a high coefficient of friction. Wear rate increases with load and speed. Addition of solid lubricant additives helps in improving the friction and wear of the polymer. Composites with MoS2‐Sb2O3and PTFE gave better results than composites made by the addition of graphite and MoS2graphite. Wear rate of these composites increased with load and speed; but load and speed had little effect on frictio

ISSN:0265-6582    

DOI:10.1002/jsl.3000040304

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractThere is increasing demand for high temperature greases capable of operating in the range of 175–235°C. In this paper, one type of grease, polyurea, is described, and its preparation given, in terms of raw materials, temperature, solvents, base fluids including synthetics, catalysts, additives and thickeners. Two typical preparation procedures are described. The properties of polyurea greases are then reviewed, with detailed tabular matter giv

ISSN:0265-6582    

DOI:10.1002/jsl.3000040305

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

ISSN:0265-6582    

DOI:10.1002/jsl.3000040306

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

ISSN:0265-6582    

DOI:10.1002/jsl.3000040307

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

ISSN:0265-6582    

DOI:10.1002/jsl.3000040308

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

ISSN:0265-6582    

DOI:10.1002/jsl.3000040309

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

ISSN:0265-6582    

DOI:10.1002/jsl.3000040301

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY