Mechanically Strong Multifilament Fibers Spun from Cellulose Solution via Inducing Formation of Nanofibers

Mechanically strong cellulose fibers spun with environmentally friendly technology have been under tremendous consideration in the textile industry. Here, by inducing the nanofibrous structure formation, a novel cellulose fiber with high strength has been designed and spun successfully on a lab-scale spinning machine. The cellulose–NaOH–urea solution containing 0.5 wt % LiOH was regenerated in 15 wt % phytic acid/5 wt % Na2SO4 aqueous solution at 5 °C, in which the alkali–urea complex as shell on the cellulose chain was destroyed, so the naked stiff macromolecules aggregated sufficiently in a parallel manner to form nanofibers with apparent average diameter of 25 nm. The cellulose fibers consisting of the nanofibers exhibited high degree of orientation with Herman’s parameter of 0.9 and excellent mechanical properties with tensile strength of 3.5 cN/dtex in the dry state and 2.5 cN/dtex in the wet state, as well as low fibrillation. This work provided a novel approach to produce high-quality cellulose multifilament with nanofibrous structure, showing a great potential in the material processing.