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Preparation and Characterization of Regenerated Cellulose Fibers from a Novel Solvent System

Liquid crystalline solutions of cellulose were prepared by dissolving cellulose in the compound solvent of phosphoric acid/poly‐phosphoric acid. Influence of P2O5 concentration in the compound solvent on solubility and dissolution behavior of cellulose was evaluated. The experiment results indicated that the P2O5 concentration could play an important role in breaking the intra‐ and intermolecular hydrogen bonding of cellulose and increasing the expansion of random coil dimensions of cellulose molecules. Based on these experimental results, the dissolution process and mechanism were depicted. Moreover, novel regenerated cellulose fibers have been successfully spun from this cellulose dope. The tensile strength, elongation at break, and crystallinity of the resulting fibers were 5.35 cN/dtex, 3.97%, and 50%, respectively. The structure of the fibers and original pulps were analyzed by using nuclear magnetic resonance (13C NMR), wide‐angle X‐ray diffraction (WAXD), and Fourier transform infrared (FT‐IR) spectroscopy. The results indicated that the cellulose I crystalline structure was transferred into cellulose II crystalline structure during the regeneration process of the fibers.