Cellulose acetate fibers with improved mechanical strength prepared with aqueous NMMO as solvent

Cellulose diacetate (CA) was successfully dissolved in N-methylmorpholine N-oxide aqueous solution (NMMO·H 2 O). The CA degraded little during the dissolving process and the homogenous CA/NMMO·H 2 O solutions were obtained even when the concentration was up to 18%. From the rheological behavior of the CA/NMMO·H 2 O solution, it was found that the viscosity of the solution was lower than that of lyocell solution, which is due to the lower degree of polymerization and the substitute of acetyl group. Then CA fibers were prepared by dry-jet wet spinning process. The tenacity and the E-modulus of the regenerated CA fibers were up to 3.0 cN/dtex and 75 cN/dtex respectively, and the former was larger than that of industrial CA fibers prepared by dry spinning process. This is related to the structure of the CA fibers, because the crystallinity, crystal orientation of the fibers can be improved by high draw ratio during dry-jet wet spinning process. Otherwise, the CA fibers showed no fibrillation tendency, which showed improved wearing comfort compared to lyocell fibers. This work provided an effective way to produce new CA fibers with higher tensile strength. Graphical abstract