Diesters biolubricant base oil, oleyl 9(12)-hydroxy-10(13)-oleioxy-12(9)-octadecanoate (OLHYOOD) was synthesized based on the esterification reaction of 9,12-hydroxy-10,13-oleioxy-12-octadecanoic acid (HYOOA) with oleyl alcohol (OL) and catalyzed by sulfuric acid (SA). Optimum conditions of the experiment to obtain high yield % of OLHYOOD were predicted at ratio of OL/HYOOA of 2？:？1？mol/mol, ratio of SA/HYOOA of 0.7？:？1？mol/mol, reaction temperature 110°C, and 7？h of reaction time. At this condition, the yield of OLHYOOD was 88.7%. Disappearance of carboxylic acid (C=O) peak has been observed by FTIR with appearance of ester (C=O) peak at 1738？cm？1. 13C, and 1H？NMR spectra analyses confirmed the result of OLHYOOD with the appearance of carbon-ester (C=O) chemical shift at 173.93？ppm and at 4.05？ppm for 13C and 1H？NMR, respectively. The physicochemical characteristics of the OLHYOOD were also determined, which showed improved low temperature properties (PP) ？62°C, viscosity index (VI) at 192 and also increased oxidative stability (OT) up to 215.24°C. 1. Introduction Oleochemicals that are derived from natural fats and oils are referred to as natural oleochemicals . Industrially, most fatty acids are obtained from animal or vegetable sources. It is possible to produce several industrial products from fatty acids (saturated and unsaturated). Fatty acid products have different utilization as resins, plastics, perfumes, coatings, flavors, cosmetics, solvents, soaps, medicinals, biofuels, and biolubricants . Synthetic biolubricant based on renewable resources are important in developing environmentally acceptable lubricating oils . Currently, lubricant-based petroleum worldwide end up in the environment via total loss applications, spills, or major accidents. A fact remains that about 3 million tones are lost in the European environment every year originating from loss and high-risk lubricants mostly based on mineral oil. Emissions of mineral oil may appear to be negligible importance compared to an accident involving an oil tanker spill . And also, the emissions of mineral oil arising from lubricant applications in water make lubricants contribution to the pollution of water much more significant . In the last decade, a lot of interest was developed to use environmental friendly biolubricant fluids . The use of environmentally acceptable vegetable-oil-based product as biolubricants has many advantages. They are nontoxic, biodegradable, derived from renewable resource and have a reasonable cost when compared to other synthetic fluids .
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