Sintesis Galaktomanan Oleat Melalui Transesterifikasi Galaktomanan Biji Aren (Arenga Pinnata Merr.) dan Metil Oleat Menggunakan Katalis NaHCO3 dengan Radiasi Mikrowave

Abstract

Galactomannan oleate has been syhntesis through a transesterification reaction of galactomannan sugar palm (Arenga pinnata Merr.) with methyl oleate using NaHCO3 catalyst by heating using microwave. Galactomannan oleate were analyzed with FT-IR and SEM. Methyl oleate was first synthesized through the esterification reaction of oleate acid with methanol using H2SO4 as catalyst by heating using a microwave. Based on the monitoring of the reaction with TLC, the reaction for the formation of methyl oleate last for 30 minutes. The resulting methyl oleate was then esterified with galactomannan using NaHCO3 catalyst by heating using microwave. The synthesis was carried out with various variations mole of the addition of methyl oleate galactomannan with the ratio of 1:1, 1:2, and 1:3. The formation of galactomannan oleate is indicated by the presence of an absorption band at wave number 3410,15 cm -1 at mole variation 1:1, at 3421,72 cm -1 mole variation 1:2, at 3350,35 cm -1 mole variation 1:3, which indicates the presence of OH group and indicates presence of C=O at wave 1741,72 from the galactomannan oleate formation . The formation of methyl oleate is indicated by the presence of an absorption band at a wave number of 1742 cm-1 which indicates the presence of C=O ester. The resulting DS value increased with the increase in the amount of methyl oleate, where the highest DS value was obtained at a variation of 1:2 is 0,99. Emulsion stability on galactomannan and galactomannan oleate at a ratio of 1:1, 1:2, and 1:3 obtained that galactomannan oleat at aratio 1:1 had the stabilized ISE with a value of 0,94 ml. The results of the morphological analysis showed changes in the surface morphology of galactomannans which were not smooth and uneven and had many pores, while Galactomannan oleate had fewer pores.