Sintesis dan Pencirian Ester dari Asam Oleat dan Poliol Berbasis- Onggok

Abstract

Onggok is a solid waste from tapioca industry that contains cellulose. Polyhydroxyl compounds (polyol) can be produced through liquefaction of cellulose. Cellulose liquefaction was carried out in ethylene glycol medium catalyzed by sulfuric acid, at 150 °C over 4 h, with 98.72% of yield. The polyol was esterified with oleic acid and sulfuric acid as catalyst to synthesize a nonionic surfactant. Esterification was carried out at 140 °C in 4 h, with oleic acid-polyol ratios of 1:2, 1:1, and 2:1. The free fatty acid contents and acid values of the esterification products were 23.07, 43.05, 60.97% and 32.67, 60.97, 86.34 mg KOH/g, respectively. Infrared spectrum of the ester products showed a C=O stretching band in wavenumber region of 1750–1715 cm-1, which was not present in polyol, but in oleic acid (1720–1680 cm-1). Intensity of O-H stretching band in ester products was weaker than in polyol spectrum (around 3400 cm-1) and C-H stretching band of the ester products in 2950–2800 cm-1 was originated from oleic acid.