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To prepare semi‐synthetic oils satisfying the classification API SF/CC and SAE 10W30 from mineral base oils derived from high paraffinic petroleum, synthetic alkylbenzenes base oils, and suitable additives.

The mixtures of base mineral oils of deep hydro‐isomerization derived from high‐paraffinic petroleum (viscosity at 100°C is 12.5 cSt) and the mixtures of the synthetic alkyl aromatics oils with the naphthenic components (viscosity at 100°C of 8.0 cSt) were used as base oil. viscosity‐temperature properties, pour points, and flash points were modified by mixing of suitable additives. Octan M‐1, Octan M‐2, Octan M‐3, and Octan M‐4 oils were obtained by application of suitable additives into the prepared base oils B‐C. In order to get the SAE 10W30 requirements the viscous additive was added (0.4‐0.6 mass percent) to prepared base oils. For obtaining the API/SF/CC grade oils, package additive (Hitec 9229) additive was added (4.7 mass percent) to the mixture. The oil (Octan M‐1) was tested in the engine of Mercedes‐Benz model 230 car and positive results over 20,000 km running.

It was observed that, viscosities and pour points change linearly as the mass percent of alkylbenzenes the in the base oil mixture is changed. This realizes the possibility of the creation of semi‐synthetic motor oil of desired properties in the case of lack of other low‐viscosity synthetic component such as poly‐á‐olefins, diester and polyester oil. The obtained oils are useful for service in relatively mild climatic conditions (average temperature of the winter period −15 to −30°C).

The obtained oils cannot fully satisfy the requirements of the engines by pour point and low‐temperature characteristics in the absence of additives.

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.

Details practical information on preparation of four semi‐synthetic oils satisfying the classification API SF/CC are reported.

The purpose of this paper is to investigate alternatives for four stroke 10w40 motorcycle engine oils. Today, mineral and synthetic‐based lubricants are widely used but because of ecological aspects, which are gaining in importance nowadays and limited resources of mineral oils, environmentally‐friendly biobased lubricants are gaining in importance. Biobased lubricants are also important for using national resources rather than importing crude oils which are limited. The main consumption of lubricant market is motor oils. In this study, starting from mineral, synthetic and biobased lubricants; mineral, synthetic, biomineral and biosynthetic based four stroke motorcycle engine oils (10w40) are prepared, then lubricity properties of the motor oils are determined.

The lubricity tests of the samples are done in a fixed forced lubricity test rig and the motorcycle motor oil preparation are conducted according to ASTM test methods.

The results show that 5 per cent of biobased lubricants will be suitable for preparing 10w40 motor oils in both mineral and synthetic based motor oils. Also improvements in the lubricity properties with the blend with biobased lubricants are seen.

The paper presents biomineral and biosynthetic 10w40 motor oils as alternative candidates for motorcycle motor oils.

Economic pressures are driving fleets to substantially increase their maintenance intervals. To meet this challenge, both the original equipment manufacturers (OEM) and the lubricant suppliers have developed new and better products to give users the benefits of extended service intervals while at the same time maintaining equipment life and reducing operating costs. This paper will examine the options available in formulating extended drain transmission and axle lubricants by comparing four products designed to meet the OEM extended service interval requirements. Bench test and field test data will be reviewed which show that by optimizing the base oil as well as the additive system, both synthetic as well as properly formulated mineral oil products can give excellent extended drain performance. With mounting economic pressures in the trucking industry, these new products will give maintenance personnel additional product choices as they move their fleets to extended drain transmission and axle lubricants in an effort to safely extend equipment life and reduce total maintenance costs.

“The properties of conventional coolants are limited by the natural characteristics of their hydrocarbon bases which can only be varied slightly by complex formulation, whereas a single synthetic coolant can be formulated to cover a wide range of machining operations”.

The paper presents the results of research carried out on esters of carbonic, adipic, and sebacic acids with respect to their use as components of fully synthetic lubricating oil produced from a polyalphaolefin base. Straight dicarboxylic acid esters were synthesized in a transesterification reaction of dimethyl carbonate, dimethyl adipate, and dimethyl sebacate with 2‐ethylhexanol and 3,5,5‐trimethylhexanol.

Oligomeric esters of adipic acid and sebacic acid were synthesized using neopentyl glycol, appropriate dimethyl adipate or dimethyl sebacate and 2‐ethylhexanol as the starting material. The basic physicochemical properties of esters were determined and their compatibility with synthetic oils were defined. They were also evaluated with respect to resistance under the influence of thermo‐oxidative factors, evaporation and susceptibility to hydrolytic decomposition. The selected esters were complemented with commercial additives to make up a fully synthetic lubricating oil with a polialphaolefin base. A special attention was paid to the effect of ester compounds on the physicochemical properties of the formulated oil.

The obtained results show that straight adipates and sebacates of 2‐ethylhexanol and 3,5,5‐trimethylhexanol as well as oligomeric esters in which molecules are terminated with 2‐ethylhexyl group can be used as component of lubricating oils. The addition of these esters reduced the pour point by a few degrees in comparison with the tested base oil. The temperature fell below 40°C. The presence of esters significantly improved the viscosity index. A positive influence of esters on the lubricating properties of the formulated oil was also observed. On the contrary, dialkyl carbonates show too low boiling point, which is indicated by the high amount of volatile components, 19‐22 percent, in final product. Adipic and sebacic oligomers containing methoxyl groups in their structures proved to be immiscible with polyalphaolefins.

The achievement of this work is the synthesis of new oligomeric esters of dicarboxylic acids, which can be excellent additives for improving properties of synthetic oils. Further studies will be focused on the use of esters as components of engine oils. This requires real motor tests.

SINCE the Second World War, no lubrication problem has offered a greater challenge to chemists than that posed by the aircraft gas turbine engine. Mineral oils, which for many years had provided satisfactory lubrication of piston‐engined aircraft, had obvious limitations when considering jet engines, and more than ten years ago the need for new lubricants was realized. The requirements were improved high temperature performance coupled with low volatility, fluidity at low temperatures, and high load‐carrying capacity. The requirements of satisfactory lubricants for aircraft gas turbine engines were discussed as long ago as 1947 by Williams, who proposed certain tentative test methods and pointed out the limitations of the mineral oils currently in use. At that time research on potential synthetic lubricants had begun both in the U.K. and in the U.S.A., and during the next four or five years bench engine tests were carried out, followed by flight trials in aircraft.

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.

SOME details of practical tests with synthetic lubricating oils, developed during war time in Germany, have recently been published, and the following is an abstract from an article by H. Külbel and A. Meusel, entitled Ueber die praktische Erprobung synthetischer Schmieröle, published in a recent issue of Konstruktion (1951, Vol. 3, No. 7). These tests relate to the use of these lubricants in automobile engines and also as steam cylinder lubricants. A preliminary note by the Editor also points out that these lubricants may prove useful in marine diesel engines burning heavy bunker oil, since they appear to possess the property of softening the hard carbon formed by these fuel oils.

Workmanship concerns lead to more focus on volatile materials, released by industrial lubricants. Typically, flash point test and thermo‐gravimetrical analysis (TGA) are used to investigate basestock volatility, but they do not address long‐term decomposition tendencies of lubricants. The extent of volatile losses due to chemical degradation (oxidation, hydrolysis, dissociation, etc.) remains unclear.

Vaporisation tendencies of eight additive‐free bio‐based, synthetic and mineral basestocks with similar viscosities were compared experimentally in a 30‐80 h degradation test. Thin films (30‐50 μm) of oils were placed on the steel surface and heated to 130‐140°C with periodic cooling to room temperatures for gravimetric measurement of volatile losses.

Mineral oils lost some fractions initially, but their evaporation subsided afterwards. To the contrary, PAO, polyglycol and polyol ester type oils showed low losses early into the test, but later they started producing high amounts of volatiles. After approx. 10‐15 h the evaporation from mineral oils was clearly lower than that from synthetic or bio‐based oils with substantially higher flash points.

Test results challenge the existing viewpoint that viscous oils with high flash points are non‐volatile. It was found that even fully synthetic and bio‐based oils lost more than 30 wt.% contents, despite being considered almost non‐volatile. Such extensive decomposition of oil films should be taken into account when making the equipment‐engineering or workmanship‐related decisions in the industry.