摘要:

AbstractOverbased and neutral magnesium and calcium salts of sulphonic acids were prepared, these salts having a very complex micellar structure when added to a lubricant oil. Using solutions in isooctane, the authors studied this structure by ultracentrifugation. The following results were obtained: a correlation between the alkaline reserve of additives and the size of the micelle; a difference in the size of the micelle in relation to the earth metal used; and the influence of the solvent used in the evolution of the micellar structure in the solution.

ISSN:0954-0075    

DOI:10.1002/ls.3010010302

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractDifferential thermal analysis (DTA) and thermogravimetry (TG) methods have been developed to evaluate the thermal and thermooxidation stability of different lubricating oils. Measurements are carried out either by heating the oil sample at a constant rate (direct programme) or by keeping it at a fixed high temperature (isothermal programme). Oxygen at a constant flow rate is used for thermooxidation measurements. Tested samples included different viscosity grades: neutral base oils, unadditivated lubricating oil blends, and industrial oils. The mechanism of thermal decomposition for ZDDP and the estimation of its optimum concentration was also considered.

ISSN:0954-0075    

DOI:10.1002/ls.3010010303

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractOlefin copolymers and terpolymers (OCPs) are used as viscosity modifiers in a large proportion of the European and world multigrade oil market. The polymer properties of the basic ethylene propylene polymers are critical to the physical characteristics of the final lubricant and its engine performance. The important parameters are discussed. Ethylene propylene polymers intended for use in other industrial applications should be checked thoroughly to avoid potential field problems. Modifications of these speciality OCPs to dispersant polymers enhance diesel and dispersant lubricant properties, enabling the most severe lubricant performance requirements to be met. The paper also reviews developments reported in the literature on the production and handling of the products together with their application, particularly with reference to their effect on low temperature properties, engine cleanliness, wear and fuel economy of the lubricant.

ISSN:0954-0075    

DOI:10.1002/ls.3010010304

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractWork in the author's laboratory has shown that certain specially designed overbased sulphonate‐compounds function as extreme pressure agents in heavy duty metalworking operations. Depending upon the application, these materials may be used individually or in combination with conventional EP agents; they have also shown a synergism with active sulphur compounds. Film strength tests, controlled tool life evaluations, and field trials confirm that high load‐bearing properties are imparted to metalworking fluid formulations. In addition, we have seen dramatic effects on the quality of machined metal surfaces. As an extremely important benefit, these unconventional extreme pressure agents are environmentally accepta

ISSN:0954-0075    

DOI:10.1002/ls.3010010305

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

ISSN:0954-0075    

DOI:10.1002/ls.3010010301

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY