Wet Spinning and Structure Analysis of α-1,3-Glucan Regenerated Fibers

Because of the increasing concerns related to fiber wastes resulting from non-biodegradable plastics and their impact in terms of environmental pollution, the demand for the development of biodegradable fibers has increased. Regenerated fibers of polysaccharides are expected as biomass fibers because of their biodegradability and structural variety. In this study, a linear polysaccharide synthesized by in vitro enzymatic polymerization, alpha-1,3-glucan, was wet-spun using 8% (w/w) lithium chloride in a dimethylacetamide solution. When ethanol (EtOH) was used in the coagulation bath, the resulting fibers were transparent, flexible, and dense, whereas the fibers produced with water in the coagulation bath were translucent, brittle, and aggregated. The former regenerated fibers exhibited tensile strength (11 cN/tex, 138 MPa), elongation at break (12%), and Young's modulus (3.5 GPa). The X-ray fiber diagram of the regenerated fibers coagulated in EtOH showed that the fibers were well-oriented along the fiber axis. The crystalline structure was determined to consist of a twofold helix with crystal lattice parameters of a = 1.59 nm, b = 0.976 nm, and c (fiber axis) = 0.852 nm.