Carboxyethylated Microfibrillated Cellulose Fibers Prepared from Different Raw Materials

Carboxyethylation pretreatment was used to prepare microfibrillated cellulose(MFC) in this study. In order to evaluate the adaptability of this pretreatment method, carboxyethylated MFC was prepared from six different cellulosic materials. The carboxyl content, degree of polymerization, water retention value, charge density, chemical structure,size distribution, and micromorphology of the materials before and after pretreatment and grinding were studied and compared. The viscosity,ultraviolet(UV) transmittance, and thermal stability of the MFC samples at a certain concentration were determined. The results showed that the carboxyl content, water retention value, charge density, degree of polymerization, size distribution, and micromorphology of the pretreated and ground samples varied with those of the raw materials. The initial viscosity varied based on the type of raw material used. The MFC suspension prepared from cotton linter pulp had the highest UV transmittance, while the MFC prepared from bleached softwood kraft pulp had the highest viscosity at a low shear rate.After thermal degradation, the amount of residual char from the MFC prepared with the thermo-mechanical pulp was slightly higher than that of the other MFCs. This study demonstrates that carboxyethylation is an effective pretreatment method for different cellulosic materials.