Resumen
Bio renewable materials from different natural resources shows a great interest in exploration of new materials for advanced application. Among different materials, cellulose is the most important and common polymer available naturally. As an improvement for better properties, cellulose nanocrystal (CNC) which is derived from native cellulose has attracted many researchers due to its uniqueness. Significant advances in the preparation of CNC have been made previously including acid hydrolysis, mechanical isolation, ultrasonication and enzymatic method. Among these, acid hydrolysis method is simplest, well developed technique allowing precise control over the CNC physical and chemical characteristics. Previously, isolation via single acid shows some limitation on CNC produced. Thus, this study focusses on isolation of CNC via mixed acid (sulfuric and phosphoric) hydrolysis. In this study, two factors which affect CNC were studied which are temperature and reaction time. The results obtained has been analysed using FESEM to compare the morphology of raw material (MCC) and CNC produced from the hydrolysis process. Besides that, FTIR was used in the characterization of CNC. The spectra show significant difference between MCC and CNC which indicate the presence sulphate group on the surface of CNC. In thermal stability characterization using TGA, it shows an improvement of degradation temperature compared to CNC produced via single acid (sulfuric acid). While in dispersion stability, dispersion of CNC is decreasing in 1 hour compared to previous study as different method has been implemented. However, CNC at 90°C shows rapid sedimentation compared to other. Therefore, isolation of CNC can be accomplished by using mixed acid as it improves the limitation of CNC produced by single acid.