Université de Lyon, Université Claude Bernard Lyon 1, UMR CNRS 5223, Ingénierie des Matériaux Polymères IMP@Lyon1, 15 bd Latarjet, 69622 Villeurbanne Cedex, France.
Carbohydr Polym. 2013 Oct 15;98(1):50-63. doi: 10.1016/j.carbpol.2013.04.070. Epub 2013 May 4.
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.
我们研究了水醇壳聚糖溶液的纺丝。通过在加热挤出的水醇溶液时蒸发水，优化了纺丝液的组成，以获得连续的醇凝胶纤维。然后将该醇凝胶纤维在碱性水溶液中中和，并在水中洗涤以除去残余的酒精和盐，然后进行最终干燥。根据中和步骤中纤维中酒精的含量、特定的酒精-壳聚糖相互作用以及凝固碱的性质和浓度，该过程得到了不同无水和水合变体比例的半结晶壳聚糖纤维。与经典的退火方法相反，通过在疏水环境中中和聚合物，在不显著降低分子量的情况下，得到了主要为无水晶体的形成。控制变体含量与中和步骤中溶剂（酒精部分）的疏水性有关。
