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The purpose of this paper is to study a novel Mannich adduct of benztriazole-containing diphenylamine (coded as BD) and its anti-oxidation properties as an additive in two typical synthetic ester-based oils.

The anti-oxidation properties in two typical synthetic ester-based oils were evaluated in detail, using rotating pressure vessel oxidation test. The tribological properties of BD in synthetic ester-based oil (A51) were also tested with Optimal SRV-I oscillating friction and wear tester at atmosphere.

The results of tests demonstrated that the novel BD compound is, indeed, a high-performance anti-oxidation additive that was able to remarkably improve the oxidation stability of synthetic ester-based oils, when it was added at only 0.5 per cent concentration and compared with the base oils containing 0.5 per cent of the commercial available antioxidant additives such as 2, 6-di-tert-butyl-4-methylphenol and octyl-butyl diphenylamine. A plausible mechanism of exceptional synergistic anti-oxidation was proposed.

This paper first investigated the anti-oxidation properties and mechanisms of the compound with the structure of BD, which can be very useful and would promote the application of BD antioxidant in the lubricant industry.

Focuses on oleochemicals, a natural alternative to mineral oils for use in liquid lubricants, metal working coolants, quenchants and hydraulic fluids. Natural oil based products generally have many advantages over mineral oils, including lower volatility, better inherent lubricity, higher viscosity index, higher bulk modulus, better fire resistance and better solvency. Details the manufacturing process.

The aim of this work is to synthesize neopentyl glycol oligoesters based on adipic acid and rapeseed oil (NOAR) which may be used as the renewable and environmentally acceptable base fluids to replace mineral oils in the future.

Oligomeric intermediates were synthesized in the first esterification of neopentyl glycol with adipic acid and characterized by Gas Chromatography-Mass Spectrometer (GC-MS) to calculate the average oligomerisation degree. NOAR were synthesized in the second esterification of oligomeric intermediates with rapeseed oil fatty acid. The effects of average oligomerisation degree on the viscosity, viscosity index, pour point, oxidative stability and biodegradability of NOAR were investigated; the tribological properties and thermal stability of NOAR were evaluated by four-ball tribometer and TGA, respectively.

Results show that with the increase of average oligomerisation degree from 2.10 to 4.34, the viscosity of NOAR increased from 101.1 to 182.0 (mm2/s) at 40°C and 18.3 to 30.1 (mm2/s) at 100°, respectively, and their oxidation stability can be improved as well. The yields of NOAR were 83.3-89.4 per cent, and the evaluated properties were as follows: viscosity index of over 200, pour point of below −43°C, biodegradation rate of more than 96 per cent, maximum non-seizure load (PB value) of 784 N, wear scar diameters of 0.40 mm and thermal decomposition temperature of higher than 300°C.

This work provides a method to synthesize rapeseed oil-based oligoesters which can serve as the renewable and environmentally acceptable base fluids with tunable viscosity by controlling the oligomerisation degree of esterification.

The purpose of this paper is to synthesize amines/phenolic antioxidants by a new method and to characterize the influence of antioxidants on thermo-oxidative degradation in trimethylolpropane trioleate (TMPTO) base oil.

The molecule structures of antioxidants and lubricants were confirmed using Fourier transform infrared spectroscopy (FTIR). The oxidative stability of antioxidants and lubricants was evaluated by pressurized differential scanning calorimetry (PDSC).

These findings suggested that butyl-octyl-diphenylamine has obvious advantage on kinematic viscosity inhibition, and amine-phenol combination antioxidant has a slightly better suppression of total acid in TMPTO under thermal oxidation at 200°C for 96 h. The FTIR characterizations showed that all antioxidants could protect the basic structure of TMPTO in the early stage of thermal degradation.

Under the action of butyl-octyl-diphenylamine, the dehydrogenation of TMPTO is easily met with the alkenyl hydrogen = C–H bond in the unsaturated C = C. Meanwhile, as octadecyl 3-(3, 5-di-tert-butyl-4-hydroxyphenyl)propionate protects TMPTO, the unsaturated C = C bond in the base oil molecule easily breaks down during transition.

The purpose of this paper is to examine the preparation of asymmetric mixed esters of methylolcyclohexanols in order to decrease the pour point and increase the thermal stability of base oils.

The aldol condensation reaction of cyclohexanone with paraformaldehyde is modified to give mixture of alicyclic polyols. The obtained mixture was subsequently esterified by different pure and mixed linear mono carboxylic acids to give asymmetric mixture of esters of methylolcyclohexanols/ones.

The obtained base lubricants showed better wear preventive characteristcs (four‐ball rolling contact test) compared with previously reported and commercially available ester base lubricants.

Because of the complexity of the obtained mixture, it was impossible to study the structure and composition of the obtained products by modern techniques such as high field NMR spectroscopy.

The obtained materials are slightly acidic and should be neutralized before use or formulation.

The paper presents a new process for obtaining synthetic ester base lubricants from mixed polyols of neo structure, which was obtained from aldol condensation reaction of cyclohexanone and paraformaldehyde, and linear aliphatic monocarboxylic acids. The key step in this process is modifying the reaction condition for obtaining mixture of polyols, and not pure 2,2,6,6‐tetramethylolcyclohexanol. This allows one to obtain asymmetrical and complex mixture of esterification products, which is favored in the production of synthetic ester base stocks, having excellent viscosity‐temperature properties, decreased pour point, and increased thermal stability. The synthesized ester base lubricants also show excellent viscosity‐temperature properties compared with ester base lubricants of the same family.

This paper seeks to outline the technical characteristics of certain biodegradable lubricants which can lead to potential energy savings.

Reviews the reasons for introduction of biodegradable lubricants, and describes the outcome of development and establishment of suitable range of lubricants for almost all applications.

Plant‐based lubricants have low toxicity, they are derived from crop resources, they are recognised as safer to use, and are rapidly biodegradable when spilled on to open land or into water. As such they break down to reduce pollution burden and are favoured by the Environment Agency when used near watercourses. Products have been developed now for almost all applications including hydraulics, engines, transmissions, compressors, metalworking, turbines, and for use in all industry sectors. Latest generation biolubricants, however, give additional advantages above and beyond the original concept to reduce pollution: the latest products have high levels of performance in terms of both loading and temperature. In particular, their frictional characteristics have been shown to be considerably more favourable than those for mineral oil, offering energy reduction during use.

The paper is restricted to findings based on ester‐based synthetic lubricants where the esters have been derived principally from renewable resources.

Quite apart from their environmental attributes, reduced energy consumption and therefore lower variable costs are now possible, and the concept of use of these oils to give distinct savings is becoming recognised.

This study emphasises that distinct advantages for synthetic lubricants, particularly for biodegradable synthetic ester lubricants derived from renewable resources, are now being realised.

The aim of this paper is to focus on the production of mixed‐synthetic diester base oils from the waste of electrochemical production of sebacic acid (mixtures of methyl esters of dicarboxylic acids, HOOC(CH₂)nCOOH, n=4, 6, 8).

The mixtures of methyl esters of dicarboxylic acids ((CH₂)n, n=4, 6, 8) are transesterified by pure alcohols and also different mixtures of aliphatic monohydric alcohols, C6‐C10 of iso‐ and normal structure, in the presence of a new catalyst system (tetra‐n‐butyl orthotitanate, Ti(O‐n‐Bu)₄). The effects of starting materials ratios on the reaction progress and characteristic features of the obtained diester oils have been studied.

The obtained mixed diester oils showed similar thermal properties and low pour point (minimum −70°C), and improved viscosity‐temperature properties compared with commercially available dioctyl sebacate (DOS) and dioctyl adipate (DOA) diester oils.

Because of the complexity of the obtained mixture, it was impossible to study the structure and composition of the obtained products by modern techniques such as high field NMR spectroscopy.

The mixtures of methyl esters of dicarboxylic acids obtained from different batches of sebacic acid production have different molar ratios and must be analyzed before use. The process is based on transesterification reactions of methyl esters of mixture of the aliphatic dicarboxylic acids ((CH₂)n, n=4, 6, 8) by mixture of aliphatic alcohols having iso‐ and normal structure in the presence of a new transesterification catalyst (mixture of p‐toluene sulfonic acid and tetra‐n‐butyl orthotitanate). The obtained mixed diester oils showed similar thermal properties, low pour point (minimum −70°C) and improved viscosity‐temperature properties compared with commercially available DOS and DOA diester oils.

The paper illustrates a new process for the production of mixed‐synthetic diester base oils.

To develop a new, biodegradable hydraulic fluid, numerous standard and in‐house screening tests are necessary to verify the lubricating properties. It was further determined that evaluation within a hydrostatic transmission, simulating field operating conditions, as a final test is critical but needed, as new fluids will occasionally fail this test, although all prior tests were passed. This paper describes recent experiences at the authors’ institute with ester based hydraulic fluids run in a heavily loaded hydrostatic transmission under laboratory conditions on the so‐called “flywheel test rig”. Change of fluid properties and wear behavior of the hydrostatic components are compared to derive statements about the fluids’ behavior to be expected in the field application.

The paper aims to study the effects of introducing oxypropyl segments into the trimethylolpropane (TMP) esters along with lowering the linear chain length from C₅‐C₉ to C₅‐C₆ on the properties of base lubricants.

Various amounts of oxypropylene segments were introduced into the TMP skeleton and obtained polyols subsequently esterified by pure C₅‐, C₆‐, and mixture of C₅‐C₆‐ aliphatic monocarboxylic acids of normal structure (SFAc mixture).

Introducing oxypropylene segments into TMP skeleton, along with lowering the carboxylic acid chain length from C₅‐C₉ to C₅‐C₆, ester base lubricants obtained improved mechanical and wear preventive characteristics.

Because of complexity of obtained mixture, it was impossible to study the structure and composition of the obtained products by modern techniques such as high field NMR spectroscopy.

The obtained materials have high boiling points under reduced pressure (2 mmHg). Producing higher vacuums will make the distillation process easier.

This paper fulfils detail information on the experimentally preparation of oxypropylated TMPs as synthetic base lubricants. The synthesized compounds showed improved properties such as high viscosity at 100°C, low pour point, high flash point, and totally excellent viscosity‐temperature properties than simple TMP esters and some literature reported ester base lubricants.