Kinetika Reaksi Sintesis Karboksi Metil Glukomanan

Abstract

Cultivation of porang plants now has a promising prospect because it has a high economic value. Glucomannan content in porang is quite high (15-64% dry base). Glucomannan, the natural polymers contained in porang corms, can be modified by carboxymethylation. The synthesis of carboxy methyl glucomannan took place over two steps, alkalization and carboxymethylation. Alkalization was conduct using NaOH in ethanol 70% as the medium. The carboxymethylation steps was conducted by adding sodium chloroacetate as the reagent. The quality of carboxy methyl glucomannan was determined from its Degree of Substitution (DS). The results showed that the highest degree of substitution was 0.47 with 70% ethanol as medium and at temperature 65 o C for 150 minutes reaction time. From the data obtained, it can be seen that the reaction of glucomannan carboxymethylation proceeded at 1 st order reaction, with the collision factor value (A) of 491.227 J/mol.K and its activation energy (Ea) of 30,994.59 J/mol.K.