LAUSR

Abstract The dissolution evolution behavior and dissolution mechanism of cellulose in N -methylmorpholine- N -oxide (NMMO)/H 2 O solution, a typical aqueous solvent, were investigated. The dissolution evolution behaviors and hypothesis were characterized by polarizing microscope (POM) and Wide-angle X-ray diffraction (WAXD). Results showed that the concentration of the solvent penetrating into the native cellulose increases gradually, special swelling dissolution of different cellulose fibers is caused by the inconsistency of the structure and or composition of the fibers. The dissolving process of cellulose with the structure of amorphous regions co-existing with crystalline regions is that the solvent penetrates in the amorphous regions and weak regions where the structure is loose, causing the crystalline regions of compact structure gradual dispersing from outer to inner by the chain disentanglement of these regions, and further developed the model for the dissolving evolution behaviors of polymer with the structure of amorphous co-existing with crystalline regions and the solvent penetrating model for the swelling dissolution of cellulose fiber.