Optimization Study and Characterization of Microcrystalline Cellulose Isolated from Coconut Husk via Hydrolysis using Ionic Liquid

Abstract

This paper reports the optimization study and characterization of microcrystalline cellulose (MCC) isolated from coconut husk via hydrolysis using ionic liquid. Three process parameters, namely solvent concentration, temperature and reaction time were optimized using response surface methodology. The responses were measured in terms of percentage of solubility. Analysis of variance was carried out to obtain the most significant parameter influencing the solubility of MCC. It has been observed that the optimum solubility of MCC produced is 37.0±2.0% at optimum conditions of 90.9 °C, 92.3 minutes and solvent concentration of 65.6 wt %. Fourier transform infrared spectra have further confirmed the removal of lignin and hemicellulose from coconut husk, suggesting that almost pure MCC has been produced. Bulky form of MCC in micro‐size ranging from 10‐100 μm was observed from scanning electron microscopy micrographs, probably been caused by the inappropriate drying method. It is expected that a smaller size of crystalline cellulose could be prepared if a proper drying method such as freeze dryer was implemented.