A triphenylamine-based aggregation-enhanced emission probe for viscosity and polarity analysis of lubricating oils

Lubricating oil offers abundant information about the operating state of machine. In this work, a donor-acceptor aggregation-enhanced emission fluorescent molecule, (Z)-4-(1-cyano-2-(4-(diphenylamino)phenyl)vinyl)benzonitrile (CPA-TPA), was synthesized to investigate its function to sense...

A Comparative Study on Chemical Characterization and Properties of Surface Active Compounds From Gram-positive Bacillus and Gram-negative Ochrobactrum Strains Utilizing Pure Hydrocarbons and Waste Mineral Lubricating Oils

Mineral lubricating oils are widely used in various industrial sectors for their applications in maintenance and functioning of machineries. However, indiscriminate dumping of these used oils has resulted in polluting the natural reservoirs which subsequently destroys ecological balance. Bacteria can emulsify or lower surface tension between phases of immiscible substrates and can acquire them as their carbon and energy sources. Such a phenomenon is mediated by synthesis of extracellular polymeric substances which can function as eminent surface active compounds based on their surfactant or emulsifying nature. The comparison between bacterial strains (Gram-positive Bacillus stratosphericus A15 and Gram-negative Ochrobactrum pseudintermedium C1) on utilisation of pure straight chain hydrocarbons, waste mineral lubricating oils as sole carbon source and chemical characterization of the synthesized surface active compounds is studied. Characterization analysis by Ultraviolet Visible spectrophotometry, Fourier-transform infrared spectroscopy, Nuclear Magnetic Resonance spectroscopy, Carbon-Hydrogen-Nitrogen analysis has given detailed structural elucidation of surface active compounds. The contrasting nature of bacterial strains in utilisation of different hydrocarbons of spindle oil was observed in Gas Chromatography-Mass Spectroscopy. The variation between both strains in utilisation of hydrocarbons can be manifested in a difference in chemical structure and properties of the synthesized surface active compounds. Scanning Electron Microscopy gives detailed insight into the difference in morphological nature of the compounds. The utilisation of these lubricating oils can address waste disposal problem and offer an economical feasible approach for bacterial synthesis of surface active compounds. Additionally, their distinctive nature and properties can maneuver applications in bioremediation of toxic environmental pollutants and as biomaterials in pharmaceutics.

AN ANALYSIS OF THE INFLUENCE OF CARBON NANOPARTICLES ADDITIVE ON SELECTED PROPERTIES OF LUBRICATING OILS

This paper presents the results of an analysis of the influence of the addition of various types of carbon nanoparticles on selected essential physical and operational properties of lubricating oils. Two selected oils, i.e. the mineral base oil without additives and the typical marine lubricating circulating oil Marinol RG 1240, were modified with the addition of shungite nanoparticles, graphite nanotubes, and C60 fullerenes. The mass fraction of modifiers was 0.2% wt for each of the additives. As part of the experimental tests, measurements were made of the impact of the above-mentioned modifiers on the change in the value of the ignition temperature of oils, the effect on the changes in the value of the dynamic viscosity coefficient in the aspect of changes of temperature and shear rate, as well as the impact on the changes in the friction coefficient and the size of the wear size scar. These tests were carried out on an EraFlash automatic apparatus for determining ignition temperature using the closed cup method, with a Haake Mars III research rheometer, and a T-02U tribometer with a four-ball head.

NEW TEST RIG FOR MEASURING THE FRICTION TORQUE OF GEARBOXES IN EXTREME THERMAL CONDITIONS

A new test rig for tribological tests was developed and manufactured. It consists of a mobile device for measurement of the start-up friction torque of transmissions, in particular planetary gearboxes, and the friction torque in dynamically steady conditions, as well as a climatic chamber to stabilize the temperature of the tested gearbox in its extreme range: from -50 to +50°C. In the series of devices for tribological tests, developed and manufactured at the Institute, the new test rig is marked with the symbol T-34. The verification results correspond with the churning losses related to the viscosity characteristics of the lubricating oils. As the temperature increases, both the start-up friction torque and the friction torque under dynamically steady conditions decrease.

Lubricating oils impact crankshaft rotation speed in outboard motors

The most effective assessment of the quality of transmission and motor lubricating oils for marine engines in general and of outboard motors in particular can be given by practical tests on real engines. An important factor for improving the technical characteristics of outboard motors by reducing friction in the movable joints of the internal combustion engine and gearbox is the right choice of a lubricating oil. The stability of the engine crankshaft rotating speed, reducing noise and vibration during the outboard motor operation indicate good lubricating properties of the engine and transmission oil used. There are shown the results of comparative tests of outboard motors SEA-PRO T2.5 (two-stroke) and YAMAHA F4B (four-stroke) using the most common on the market lubricating oil and the oil produced by KUPPER, LLC (Russia). There are presented the illustrations of outboard motors SEA-PRO T2.5 and YAMAHA F4B. The tests were carried out in the laboratory conditions in a small experimental pool by specialists from the Outboard Motors Research and Production Laboratory of Astrakhan State Technical University. The control and measuring devices used were: a tachometer SEA-PRO TSP-02, a gas analyzer “Infrakar-A-02” with a built-in tachometer. It has been inferred that there is a direct dependence of the crankshaft rotation speed during long-term operation of the outboard motor on the quality and characteristics of the lubricating oil. The probability of the research on stationary propulsion systems in water transport is indicated.

Low-Temperature Rheology and Thermoanalytical Investigation of Lubricating Oils: Comparison of Phase Transition, Viscosity, and Pour Point

According to the ASTM D97, the pour point is the temperature below which petroleum products cease to flow. To evaluate the relevance of pour point measurements for synthetic lubricating oils, we investigated the crystallization, melting temperature and low-temperature flow behavior of one mineral and five synthetic lubricating oils. The classification of three groups emerged from this process. The formation of paraffin crystals in mineral oils (I) below the crystallization temperature causes shear-thinning behavior and a yield point. The crystallization temperature determined in the thermal analysis and rheology correlates well with the pour point. Synthetic lubricating oils, which solidify glass-like (II), exhibit a steady viscosity increase with falling temperature. The temperature at which viscosity reaches 1000 Pas corresponds well to the pour point. Synthetic oils, especially esters, with complex crystallization behavior (III), exhibit supercooling depending on the shear rate and cooling conditions. For these lubricating oils, the pour point provides no information for low-temperature applicability.

A novel method for the evaluation of the contamination dispersing ability of lubricants (CONTA-DISP)

Water and solid particulate contamination are the two most common contaminants of lubricated systems and may be highly problematic for these systems. To reduce downtime and prevent failure, lubricant formulations contain detergent and dispersant additives that play an important role in terms of contamination tolerance. In lack of a practical procedure for the determination of the relevant properties, a novel method for the evaluation of the dispersing ability of lubricating oils is introduced. Following and combining established lubricant analysis methods, a procedure with optimum parameters was found. An assessment of the method using fresh and artificially altered lubricating oils allowed a differentiation concerning their dispersing ability.