Evaluating automobile fuel/propulsion system technologies

Review of the lubrication of metallic surfaces by zinc dialkyl-dithiophosphates

Mobile sources critical review 1998 narsto assessment

Modern engine lubricant specifications include compositional constraints in terms of the permitted level of sulphated ash, phosphorus and sulphur (SAPS). This necessitates a reduction in the concentration of the additive zinc dialkyldithiophosphate (ZDDP) used in engine oils, and there is currently great interest in identifying anti-wear additives that contain low or zero SAPS to partially or wholly replace ZDDP.

This paper reviews the main chemical classes that are reported in the literature as potential low- or zero-SAPS anti-wear agents. There are many such possible additives, although none appears to be quite as versatile as ZDDP. Instead, combinations of anti-wear and extreme pressure additives are likely to be employed in the future. The literature reveals a strong imbalance in the amount and depth of research carried out on the various additive types, with a great deal of research on a few classes of additives and very little recent work on most others. Copyright © 2007 John Wiley & Sons, Ltd.

Low- and zero-sulphated ash, phosphorus and sulphur anti-wear additives for engine oils

Investigation of Mixing and Temperature Effects on HC/CO Emissions for Highly Dilute Low Temperature Combustion in a Light Duty Diesel Engine

Direct infrared spectrophotometric evidence of interactions between lubricating oil dispersants and a zinc dialkylphosphorodithioate (ZDP) is presented. Increasing the concentration of the dispersants polyamino monoalkenylsuccinimide, barium thiophosphonate, and basic barium dinonylbenzene sulfonate in a mineral oil containing 1.2% by weight of a ZDP decreased the intensity of the phosphorus-oxygen-carbon and phosphorus-sulfur infrared bands, and caused the appearance of a new band at 668 cm−1. The dispersants barium dinonylnaphthalene sulfonate, calcium petroleum sulfonate, and alkaline petroleum sulfonate decreased the intensity of the phosphorus-sulfur bands only after the solutions had aged, and independently of dispersant concentration. It is speculated that chemical reactions cause these interactions between the ZDP and the dispersants, and that ionic metal phosphorodithioates are formed. The possibility of association, isomeric, and complexation effects is also explored. Regardless of the exact mec...

Interactions Between a Zinc Dialkylphosphorodithioate and Lubricating Oil Dispersants

Diesel Engines: One Option to Power Future Personal Transportation Vehicles

Thermal decomposition temperatures of oil blends of the sine, nickel, and cadmium salts of the same dialkyldithiophosphoric acid were determined by the use of the isoteniscope. It was observed that the ease of decomposition and the order of stability of these metal dialkyldilhiophosphales were affected by: (a) the nature of the base oil used for the blends, (b) the presence of basic barium sulfonate in the blends, (c) the presence of air in the isoteniscope, and (d) the pressure in the isoteniscope. The relationship of the experimental results to performance studies of the metal dialkyldilhiophosphates is discussed, and a critical evaluation of the decomposition mechanisms proposed to date is presented. It is concluded that the mechanism of the thermal decomposition of the metal organodilhiophosphates is not known, and that the relationship between thermal stability and anti-scuff performance is not completely understood. Presented as an American Society of Lubrication Engineers paper at the Lubrication C...

Thermal Decomposition of Metal Dialkyldithiophosphate Oil Blends

The effects of automatic transmission fluid additives on the friction characteristics of a mineral oil are presented. Some common viscosity-index improvers, chain-breaking oxidation inhibitors, and ashless dispersants have little or no effect on the friction characteristics of the mineral oil. Conversely, some metal-organic dispersants as well as a zinc 0,0′-dialkylphosphorodithioate oxidation inhibitor alter the friction characteristics of the mineral oil. The results indicate that some of the additives are multifunctional and will render the friction characteristics of the mineral oil satisfactory. Relationships between molecular structure of the additives and friction characteristics are discussed, but general conclusions are not formulated. Presented as an American Society of Lubrication Engineers Paper at the Lubrication Conference held in Minneapolis. Minnesota, October 18–20, 1966.

Nicholas E. Gallopoulos

Papers

Interactions Between a Zinc Dialkylphosphorodithioate and Lubricating Oil Dispersants

Diesel Engines: One Option to Power Future Personal Transportation Vehicles

Thermal Decomposition of Metal Dialkyldithiophosphate Oil Blends

Friction Characteristics of Some Automatic Transmission Fluid Components

Concentrations of Nitrogen Oxides in Crankcase Gases