Lubricants ordinarily operate by keeping two sliding surfaces separated. The efficiency of a lubricant may be expressed by equations of hydrodynamics where the mechanical properties of the films of lubricants are adequately defined by the properties of bulk lubricant. In the case of water lubrication of black rubber at slow speeds and low pressures the lubricating ability of water is shown to b...

Growing demands from industry for the use of eco-friendly lubricants led research towards finding environmentally friendly products with superior lubricating characteristics. Vegetable oils and synthetic ester oils are competitive base oils used to obtain lubricants with good physico-chemical, rheological and tribotechnical properties, biodegradable lubricants without negative environmental imp...

The application of mass spectrometric techniques for the analysis of the complex mix‐ tures inherent in fuel and lubricant samples will be examined. These samples because they are naturally complex mixtures, typically requires either very high resolution mass spectrometry or one of the hyphenated techniques gas chromatography‐mass spectrometry(GC‐MS) or liquid chromatography‐mass spectrometry (...

This paper presents simulation results corresponding with the theoretical Morton effect model explained in Part I, where the 3D finite element models of bearing, shaft, and fluid film are adopted. In addition, it explains how thermal bow induced imbalance force develops in the spinning journal with time and how the vibration level is affected by the thermal bow vector. Shaft asymmetric thermal ...

New lubricants have been developed to meet the performance demands of modem refrigerants and system components. A brief review of current refrigeration oil developments is presented. It is well known that the new lubricants used with polar refrigerants tend to absorb water. The ester hydrolysis process and the effect on the essential lubricant properties are described. The effect of increased w...

The effects caused upon the physicochemical behavior of high-density polyethylene pipes by exposure to a diesel lubricant were investigated, as a function of time and temperature, by thermogravimetric and gravimetric analysis and by FTIR. The gravimetric data were satisfactorily described using Fick’s law. The fitting of the experimental points showed that diesel, which can be regarded as a mod...

In view of the rising global problems of environment pollution and degradation, the present process provides a 'green solution' to the synthesis of higher esters of lubricant range, more specifically in the range C12-C36, using different combinations of acids and alcohols, in a single step reaction. The esters produced are biodegradable in nature and have a plethora of uses, such as in additive...

The properties of butane (C4H10) lubricants confined between two approaching solids are investigated by a model that accounts for the curvature and elastic properties of the solid surfaces. We consider the linear n-butane and the branched isobutane. For the linear molecule, well defined molecular layers develop in the lubricant film when the width is of the order of a few atomic diameters. The ...

Brazil, like many emerging countries, has experienced a fast growth in the demand for automobiles in recent decades. This has produced a significant increase in the amount of hazardous waste to be disposed of, including used lubricant oil. Restrictive regulations are being used by many nations to deal with this problem, focusing on treatments, such as recycling, to avoid resource depletion. Spe...