A series of ester compounds derived from ricinoleic acid to be used as biolubricants base stock have been synthesized. The resulting products were confirmed by FTIR and NMR analyses. The synthesis was carried out in three stages: epoxidation of ricinoleic acid; synthesis of 10,12-dihydroxy-9-acyloxystearic acid from epoxidized ricinoleic acid with various fatty acids and esterification of the acyloxystearic acid products with octanol to yield octyl-10,12-dihydroxy-9-acyloxystearate. The viscosities, flash points and pour points (PP) behavior of the products were measured. The resulting esters had an increased in molar weight and viscosity and decreased in pour points as compared to ricinoleic acid.
Fats and oils in human diets are the main sources of essential fatty acids for the body. However, there is a mounting concern about the intake of foods containing trans fatty acids (TFAs) due to their deleterious effects on human. Thus, the accurate detection of fatty acids (FAs) and TFAs is needed to control and correct nutrition labeling in dietary fat samples. Accordingly, a method for the identification and quantification of FAs and TFAs in food fats by gas chromatography (GC) based on the extraction of lipids and derivatization using base catalyzed followed by trimethylsilyl-diazomethane (TMS-DM) was developed. The proposed method was evaluated to standard mixture of oleic acid (OA) (C18:1cis 9) and Elaidic acid (EA) (C18:1 trans 9) and its application to three samples of commercial margarines was demonstrated. Based on the results obtained, recovery values (R) from all the samples were close to 100%. Repeatability (RSD) values ranged between 0.78 and 2.47%, while Reproducibility (RSD) values ranged between 1.14 and 3.65%. Consequently, the proposed method is sensitive, accurate and suitable for FAs and TFAs analysis of food fats and oils and can be applied to nutritional, medicine and food studies.
1-(5-Mercapto-1,3,4-oxadiazol-2-yl)-2-(pyridine-2-ylamino)ethanone (3), has been synthesized from 2-(pyridine-2-ylamino)acetohydrazide (2). A yellow colored compound (2) was reacted with carbon disulfide and potassium hydroxide in absolute ethanol to obtain the 1-(5-mercapto-1,3,4-oxadiazol-2-yl)-2-(pyridine-2-ylamino)ethanone. Structures of the synthesized compounds were supported by means of IR, NMR, MS spectroscopic and elemental analysis. The synthesized compounds were evaluated for their antimicrobial activity and were expressed as the corresponding minimum inhibitory concentration (MIC). A brown colored compound (3) with 90% yield has been successfully synthesized. This compound was found to have significant antimicrobial activity with MIC value ranging from 30.2 - 43.2 μg cm-3. The findings of the present study indicate that cyclization of hydrazide acid group of 2-(pyridine-2-ylamino)acetohydrazide (2) into 1,3,4-oxadiazole nucleus resulted in increased antimicrobial activity.
Potassium hydroxide (KOH)-catalyzed reactions were utilized to hydrolyze Jatropha curcas seed oil. In this study, the effect of ethanolic KOH concentration, reaction temperature and reaction time to the free fatty acid (FFA) produced were investigated. D-Optimal Design was employed to study the significance of these factors and optimum conditions for the technique was predicted. The results showed that ethanolic KOH concentration was a significant variable for hydrolysis of J. curcas seed oil. In 18 experimental designs, FFA percentage of hydrolyzed J. curcas seed oil increased from 1.89% to 102.2%. The optimal conditions of response were found at 1.75M of ethanolic KOH, 65 °C and at 2 h reaction time. Fourier Transforms Infrared Spectroscopy (FTIR) spectrum analysis confirmed the concentration of ethanolic KOH i.e. at 1.00, 1.50 dan 1.75 M affect the percentage yields of J. curcas seed oil hydrolysis process.
Synthesis of new lubricants nowadays is increasing to improve the lubricity properties and the quality of lubricant. In
the current study, eight diesters with different chemical structures were tested in terms of their suitability as lubricants.
The esterification reaction was carried out using Dean-Stark distillation method with some modification. Fourier
transformation infra-red (FTIR), proton and carbon nuclear magnetic resonance (1
H-NMR and 13C-NMR), were used to
verify the chemical structure of the diesters. The results showed that the dioleyl pimelate (DOlP), dioleyl adipate (DOlA),
dioleyl glutarate (DOlG), and dioleyl succinate (DOlSuc) showed good low temperature properties with pour point values
at -10, -12, -16 and -20°C, respectively. The dioleyl dodecanedioate (DOlD) indicated remarkable flash point value at
305°C and had slightly high oxidative stability temperature (OT) at 183°C. The flash point increased with the number of
carbons for dicarboxylic acid used, while oxidative stability was affected by the unsaturated of oleyl alcohol. Tribological
study showed that the diesters were non-Newtonian except DOlD, which was Newtonian fluid. All the diesters were found
to be boundary lubricants with low coefficients of friction (COF). Overall, the results indicated that all the diesters studied
can be used as lubricating base oils.