Preparation of Carboxymethyl Cellulose from Corncob

Abstract

In this paper, to find out the best technological conditions of extracting microcrystalline cellulose from corncob by using high pressure cooking method. The optimum concentration of NaOH of the extraction of microcrystalline cellulose is 50% with the method of high pressure cooking. Preparation of carboxymethyl cellulose (CMC) from microcrystalline cellulose was carried out by an etherification process, using NaOH and monochloroacetic acid (MCA), with ethanol and water as the supporting medium. The results indicated that the best reaction condition was that the microcrystalline cellulose were alkalizated at 30 °C for 50min and etherificated at 65 °C for 3h, 85% ethanol as solvent with the molar ratio of cellulose/NaOH/MCA was 1:1:1. NaOH is added in three batches with total amount the ratio is 6:2.5:1.5. Under the optimized reaction conditions, the substitution degree (DS) of CMC is 1.02 and the viscosity is 6 mPa's, which possessed special characteristics of low viscosity.