Synthesis and Structural Characterization of Cellulose Xanthate Obtained from Oil Bean Pod Biomass

Abstract

This study investigated the synthesis and structural characterisation of cellulose xanthate derived from oil bean pod biomass. Cellulose was first isolated from oil bean pods through dewaxing, alkaline treatment, bleaching, washing and drying, and the extracted cellulose was subsequently converted to cellulose xanthate by mercerisation with 18% sodium hydroxide and reaction with carbon disulphide under alkaline conditions. The synthesised material was characterised using Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, thermogravimetric/derivative thermogravimetric analysis and BET surface analysis. FTIR analysis indicated functional groups associated with cellulose and cellulose xanthate, including O-H, C-O-C, C=S, pyranose ring and β-glycosidic linkages. XRD analysis showed crystallinity indices of 63.4% for cellulose and 76.0% for cellulose xanthate, indicating a change in crystallinity after xanthation. Thermal analysis showed initial moisture-related mass losses of 0.90% and 0.84% for cellulose and cellulose xanthate, respectively, and the main degradation occurred between 300 and 400°C. The mass losses recorded for cellulose and cellulose xanthate were 33.75% and 29.68%, respectively. SEM micrographs showed porous structures with surface roughness and aggregation. BET analysis showed that isolated cellulose had higher surface area, pore volume and average pore diameter than cellulose xanthate. Overall, the results indicate that oil bean pod biomass can serve as a precursor for cellulose xanthate with distinct structural, thermal and surface characteristics.