Dissolution behaviour and the solution property of cellulose in NaOH/Urea/Thiourea Aqueous Solvent

Untreated cellulose was directly and quickly dissolved in NaOH/thiourea/urea aqueous solvent at a 9/3/5/83 composition and pre-cooled at (-10 to +2)degrees C, and at a high shear force with 3500rpm agitating speed. The dissolving process was investigated by polarization microscope, XRD and rheometer. The result revealed that cellulose crystal forms was changed from cellulose I to cellulose II after dissolving and the crystallinity decreased. Moreover, the gel forming of cellulose has an obvious relationship with cellulose concentration and it's easy to form gel when the cellulose concentration was above 8wt%.