Sintesis Metil Oleat Menggunakan Katalis Deep Eutectic Solvents Pada Variasi Waktu Reaksi dan Kecepatan Pengadukan Pendispersi Homogen

Abstract

Methyl oleate synthesis was carried out through an esterification reaction between oleic acid and methanol using a Deep Eutectic Solvent (DES) catalyst with a homogeneous disperser. The DES catalyst was obtained from a mixture of choline chloride and urea that was heated simultaneously until melted, and then analyzed using an FT-IR spectrophotometer. The reaction conditions varied in this study were reaction time (1, 5, 10, 15, 20 minutes) and stirring speed (3000, 4000, 5000, 6000, 7000 rpm) with a mole ratio of oleic acid:methanol of 1:3 and a catalyst concentration of 15% (w/w). The percentage conversion of methyl oleate was determined by alkalimetric titration, the methyl oleate content was analyzed by gas chromatography, and functional group changes were observed using an FT-IR spectrophotometer. The conversion and yield of methyl oleate were obtained at 97.7% ± 0.36% and 94.82% ± 0.08% under the optimum reaction conditions of 15% (w/w) catalyst weight, 1:3 mole ratio of oleic acid:methanol, 10 minutes reaction time, and 5000 rpm stirring speed. The results of gas chromatography analysis of methyl oleate showed that the conversion of methyl ester reached 97.5969%, and FT-IR spectrophotometric analysis showed functional group changes indicating the disappearance of OH stretching vibration of carboxylic acid at 3400-2400 cm-1, supported by the appearance of C-O-C stretching absorption band at 1300-1000 cm-1 with three peaks and the largest intensity on the rightmost peak.