A rapid process for producing cellulose multi-filament fibers from a NaOH/thiourea solvent system

Cellulose was dissolved rapidly in 9.5 wt.-% NaOH and 4.5 wt.-% thiourea aqueous solution pre-cooled to -5 degrees C to prepare a transparent solution. Novel cellulose multi-filament fibers were spun successfully, for the first time, from the cellulose dope on an extended laboratory scale. The results from C-13 NMR, scanning electron microscopy and wide angle X-ray diffraction (WAXD) patterns indicated that the fibers exhibited cellulose H character and possessed a circular cross-section and smooth surface. The tensile strength of the novel fibers reached 1.9-2.2 cN . dtex(-1). 2D WAXD and SAXS patterns revealed that, with a drawing progress, the orientation factor increased and mechanical properties were improved.