Characterization of Carboxymethylcellulose (CMC) from Rice husk

Abstract

This study focuses on of conversion of cellulose isolated from rice husk to CMC material which has wide industrial applications especially in the drilling fluids of petroleum well. Alkaline extraction method was used for isolating the cellulose from rice husk then isolated cellulose was etherified onto sodium CMC (Na-CMC) by monochloro acetic acid (MCAA) in the presence of NaOH. Some reaction conditions were optimized, such as concentration of NaOH, solvent type, amount of MCAA and reaction time, for the production of CMC material of higher degree of substitution (DS). At optimum conditions, the as-synthesized CMC material was found to have a DS of 0.42. The isolated cellulose and the as-synthesized CMC were characterized by FT-IR spectrometer and XRD powder diffractometer and the results indicated successful introduction of carboxymethyl species to the isolated cellulose occurred. Further prove was obtained by comparison with the FT-IR spectra of pure commercial CMC material. Rheological studies were conducted for the as-synthesized CMC and some commercially available carboxy methylated cellulosic materials such as PAC-LV and PAC-RV. The results showed that, the viscosity of as-synthesized CMC material is higher than that of PAC-LV but lower than that of PAC-RV. The variation could be attributed to the lower value of DS (0.42) associated with the synthesized material. However, the results of apparent viscosity, plastic viscosity, yield points and filter loss together, demonstrated that the synthesized CMC material could be classified as viscosifier rather than fluid loss controller.