Dissolution of cellulose in NaOH/thiourea/urea aqueous solution and Preparation of Regenerated Cellulose Fiber

摘要

It is first time that cellulose was dissolved in NaOH/Thiourea/Urea aqueous solution, in which cellulose can be dissolved quickly. The optimal composition of solvent was determined by solubility of cellulose in novel solvents. The process of dissolution was observed by polarized optical microscopy. The properties of this solution was characterized by ~(13)C NMR. It was found that cellulose was dissolved directly. Cellulose in novel solvent was extruded ,and regenerated by H_2SO_4 /Na_2SO_4 aqueous solution. The structure of the resulting celluloses fibers were characterized by SEM and Wide X-ray diffraction. The novel cellulose fiber possess circular cross-sections with few inconspicuous microvoids as well as relatively high molecular weight , and a typical family II cellulose structure with higher degrees of crystallinity, which lead to a good mechanical properties.