title: Spinning of hydroalcoholic chitosan solutions.
abstract: We investigated the spinning of hydroalcoholic chitosan solutions. The dope composition was optimized in order to obtain a continuous alcogel fiber by water evaporation on heating the extruded hydroalcoholic solution. This alcogel fiber was then neutralized in aqueous alkali baths and washed in water to eliminate the residual alcohol and salts before final drying. Depending on the alcohol content in the filament at the neutralization step, on specific alcohol-chitosan interactions and on the nature and concentration of the coagulation base, the process yielded semicrystalline chitosan fibers with different proportions of anhydrous and hydrated allomorphs. Contrarily to the classical annealing method, the formation of mainly anhydrous crystals was obtained without significant molecular weight decrease by neutralizing the polymer in hydrophobic conditions. The control of allomorph content was shown to be related to the hydrophobicity of the solvent (alcohol fraction) at the neutralization step.
authors.affiliation: Université de Lyon, Université Claude Bernard Lyon 1, UMR CNRS 5223, Ingénierie des Matériaux Polymères IMP@Lyon1, 15 bd Latarjet, 69622 Villeurbanne Cedex, France.
authors.forename: Mylène
authors.initials: M
authors.lastname: Desorme
authors.forename: Alexandra
authors.initials: A
authors.lastname: Montembault
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Lucas
authors.forename: Cyrille
authors.initials: C
authors.lastname: Rochas
authors.forename: Thierry
authors.initials: T
authors.lastname: Bouet
authors.forename: Laurent
authors.initials: L
authors.lastname: David
mesh_terms: D000438:Alcohols / Q000737:chemistry*; D048271:Chitosan / Q000737:chemistry*; D004548:Elasticity; D012996:Solutions; D013696:Temperature; D014783:Viscosity; D014867:Water / Q000737:chemistry
chemical_list: D000438:Alcohols; D012996:Solutions; D014867:Water; D048271:Chitosan
keywords: Chitosan fiber; Hydroalcoholic chitosan solution; Hydrophilic and hydrophobic interactions; Physical hydrogel; Semicrystalline microstructure