Sintesis 2-Etilheksil Oleat dari Esterifikasi 2-Etilheksil Alkohol dan Asam Oleat pada Perbandingan Rasio Molar dan Berat Enzim Lipase Menggunakan Radiasi Mikrowave

Abstract

Synthesis of 2-Ethylhexyl Oleate from oleic acid and 2-ethylhexyl alcohol through esterification reaction using lipase enzyme as catalyst and microwave radiation has been conducted. The reaction conditions carried out in this study were variation of catalyst weight (0.5%; 1%; 3%; 5%; 7%; 9%; 11%) and variation of molar ratio of oleic acid to 2-ethylhexyl alcohol (1:1, 1:2, 1:3, 1:4, 1:5), with 20% microwave power and 10 minutes reaction time in each variation. The conversion of 2-Ethylhexyl Oleate was determined using alkalimetric titration. The formation of 2-Ethylhexyl Oleate was analyzed from the changes of its functional groups using FT-IR. The maximum conversion of 2-Ethylhexyl Oleate of 94.04 ± 0.40% was obtained for the catalyst weight parameter at 5% catalyst weight, 1:2 molar ratio, 20% microwave power and 10 minutes time. While for the molar ratio parameter obtained in the condition of 1:3 molar ratio, 5% catalyst weight, 20% microwave power and 10 minutes time, amounted to 99.02 ± 0.24%. The formation of ester group of 2-Etilhexyl Oleate was characterized by FT-IR spectrophotometer analysis which showed the presence of -C=O stretching ester absorption band at wave number 1710.86 and supported by -C-O-C- ester stretching vibration at wave number 1039.63 cm-1.