Swelling and dissolution mechanism of regenerated cellulosic fibers in aqueous alkaline solution containing ferric tartaric acid complex: Part I. Viscose fibers

Morphological studies of swollen viscose fibers in FeTNa (Fe–tartaric acid–NaOH complex solution) were investigated by means of microscopy. The molar ratio of Fe:tartaric acid:NaOH in FeTNa solutions was kept constant at 1:3.28:11.84 while Fe concentration ranged from 0.15 to 0.55 M and free NaOH concentration varied from 0.4 to 5 M. Fiber diameter measurements following 2 min of swelling and swelling rate of fibers up to 60 min were studied. Swelling, splitting and dissolution of viscose fibers were observed depending on concentration of Fe and free NaOH in FeTNa solutions and fiber swelling time. Splitting of a fiber into its fibrils was achieved by only swelling the fiber without a usage of any kind of force.