Chitosan: Aspects of fiber spinnability

The preparation of useful fibers from chitosan remains an interesting challenge. Chitosan is easily solubilized in aqueous acids, but these solutions generally have high solution viscosities because of the polyelectrolyte effect. The high viscosity affects the processibility of chitosan during extrusion by wet-spinning techniques. The coagulation rate, which also includes the regeneration of the free amine form of chitosan is also expected to be influenced by viscosity. In this study, the solution rheology of chitosan solutions was examined; our aim was to find the optimum compositions, in terms of chitosan, acid, and added salts, for spinnability. The diffusion of coagulants into chitosan spinning solutions is also reported. (c) 2006 Wiley Periodicals, Inc.