AbstractThe effects of chlorite bleaching on the properties of cellulose derived from oil palm empty fruit bunch (OPEFB) fiber were investigated in this work. Cellulose was extracted from oil palm empty fruit bunch fiber via chlorite bleaching, alkali treatment, and acid hydrolysis. Cellulose was extracted by varying the bleaching duration, which corresponded to 4, 8, or 12 h. Fourier transform infrared (FTIR) analysis showed that the lignin and hemicellulose were significant removed after the bleaching process, whereas no spectral differences were observed in the samples with the increase of bleaching durations. The main removal of the lignin and hemicellulose components had occurred during the bleaching process. There was only slight additional removal of lignin and hemicellulose during the further extraction process with alkali and acid hydrolysis. The peaks at 1740 cm-1 and 1246 cm-1 which represent hemicellulose and lignin, respectively, were not present in the final extracted cellulose.The cellulose yield contents did not increase with the increasing of bleaching duration from 4 h to 12 h. X-ray diffraction (XRD) analysis revealed that the crystallinity and the 200 peak of OPEFB had increased after the bleaching process. Analysis of the visible light transmittance of cellulose, after a bleaching duration of 12 h, demonstrated the highest transmittance due to the disintegration of the fibers. By increasing the bleaching duration, the temperature at 50% weight loss of OPEFB increased, suggesting that the thermal stability of cellulose had improved.