Optimization of Purified Cellulose Extraction From Corn Cob and Characterization of the Isolated Product

This study reported the isolation of cellulose from corn cob by using microwave-assisted alkaline treatment and bleaching. The Central Composite Design (CCD) approach of Response Surface Methodology (RSM) was applied to study the effect of sodium hydroxide (NaOH) concentrations (1.5-2.5M), duration of alkaline treatment (4-8 min), hydrogen peroxide (H2O2) concentrations (7-9 wt%) and bleaching time (3-7 min) on the removal percent of non-cellulosic components and impurities from corn cob. The optimized conditions obtained from this study were 2.37M NaOH, 9 wt% H2O2, alkaline treatment time of 4 min, and bleaching time – 4.20 min. The non-cellulosic part and the impurities removed under the optimized conditions in microwave-assisted alkaline treatment and bleaching amounted to 72.26 ± 0.15%. The cellulose content in the thus purified corn cob material was determined as 92.47%. The isolated corn cob cellulose was characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), and the thermogravimetric analysis (TGA). These characterizations confirmed that the alkaline treatment and microwave-assisted bleaching under the optimized conditions achieved the optimal removal percent of the non-cellulosic components and impurities from the corn cob biomass to achieve highly purified cellulose.