Effect of calcium chloride on the physical characteristics of cellulose fibers regenerated from zinc-cellulose complexes

High tensile strength cellulose fibers were made from zinc-cellulose complexes in zinc chloride solution. The formation of zinc-cellulose complex is a path-dependent process. There are many possible types of zinc-cellulose complexes that could be formed in the dissolution process of cellulose. Many metal ions were also shown to interfere with complex formation. Different zinc-cellulose complexes resulted in cellulose fibers with different physical properties. Calcium chloride can interact with zinc-cellulose complexes to produce rigid cellulose molecules that lead to cellulose fiber of high tensile strength. After examining, viscosity, Nuclear Magnetic Resonance (NMR), and Ultra-Violet (UV) spectra of cellulose solutions, it was concluded that zinc-cellulose complexes can be produced only in concentrated zinc chloride solutions. All zinc-cellulose complexes absorb UV light of wavelength at 290 nm. Calcium chloride enhanced this spectral effect. The optical density of zinc-cellulose complexes in cellulose solutions containing calcium chloride was highly correlated with the tensile strength of the regenerated cellulose fiber. This property promises to be useful for monitoring fiber formation