摘要:

AbstractOverbased detergents are commonly used in automotive and marine lubricants. Their main functions are to neutralise potentially corrosive acids and to contribute to engine cleanliness. The major types of overbased detergents that are produced commercially are phenates, sulphonates and salicylates. This paper describes the chemistry of these additive classes and reviews their properties and performance in bench and engine tests. The paper also describes a new class of overbased detergents, where novel chemistry has been used to produce new types of highly overbased phenate, sulphonate, and salicylate. These new products exhibit significant improvements in properties and performance over conventional detergents. Evidence from bench and engine tests is presented to demonstrate the benefits of the new detergent types. An appendix gives more detail on the results of tribological tests on these new detergents.

ISSN:0954-0075    

DOI:10.1002/ls.3010060402

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractIn this paper is described the role of molecular simulation as a useful quasi‐‘experimental’ tool to help in understanding the interplay between molecular structure under shear flow and the manifested tribology/rheology. The development of non‐equilibrium molecular simulation techniques are discussed, from the molecular dynamics approach through to the modelling of dispersions by brownian dynamics. Recent advances and extensions of the technique to weakly flocculated systems, such as electro‐rheological fluids, are

ISSN:0954-0075    

DOI:10.1002/ls.3010060403

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractAntiwear and extreme‐pressure additives labelled with35S were synthesised by reacting35S2Cl2with isobutylene and treating the adduct with potassium xanthate, or by labelling the unlabelled compound with elemental35S in boiling carbon di‐sulphide. Static adsorption tests of the labelled additives on iron or copper specimens show an adsorption increase with temperature. The data are in good agreement with the results of thermal analysis of the additive as such or mixed with iron or copper powder. The behaviour of the oil solutions containing labelled additives on a friction machine emphasised the formation of superficial layers on a metallic surface containing the reaction products of the additive decomposition compounds with the metal. The thickness of these layers remains nearly constant during the test but increases with normal load. Pyridine washing of the specimens removes adsorbed layers whereas chemisorbed layers remain on the metallic surf

ISSN:0954-0075    

DOI:10.1002/ls.3010060404

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractSuccinimide phosphoric acid esters have been synthesised and evaluated as antioxidants and ashless dispersant additives for crankcase lubricating oils. The synthesis is based on reacting succinimides (as prepared by the reaction of polyisobutylene, maleic anhydride and tetraethylene pentamine) with phosphorus pentoxide in the presence of alcohols with different carbon numbers Results showed that the magnitude of the oils' oxidation stability, as well as their dispersive power, are both highly related to the chemical structure of the alcohol used.

ISSN:0954-0075    

DOI:10.1002/ls.3010060405

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractA steady hydrodynamic lubrication model that includes the pressure viscosity factor has been developed for the deep‐drawing process. Equations for lubricant film thickness, radial and drawing stresses are presented. Analysis reveals that the pressure viscosity factor has a significant influence on estimating lubricant film thickness and radial and drawing stresse

ISSN:0954-0075    

DOI:10.1002/ls.3010060406

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

ISSN:0954-0075    

DOI:10.1002/ls.3010060407

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

ISSN:0954-0075    

DOI:10.1002/ls.3010060401

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY