制备非衍生化高相对分子质量水溶性壳聚糖对材料创新及应用具有重要的意义。采用真空强制渗透法,使浓碱强制渗透入甲壳素颗粒的微孔中,加速甲壳素的溶胀以及NaOH的传质,形成近似均相的脱乙酰环境。通过控制脱乙酰度在50%左右,即可获得水溶性壳聚糖。表观黏度、红外光谱、X-射线衍射、差示扫描量热分析表明:制备的水溶性壳聚糖与传统壳聚糖无本质差异;所不同的是,强制渗透法制备的产品呈非晶态,分子间氢键作用较弱,因而具有良好的水溶性。

Preparation of nonderived water-soluble chitosan with high molecular weight is of great significance to the innovation of materials and its application.In this paper,the forced penetration method for preparing a natural water-soluble chitosan have been investigated.Under the action of vacuum,the concentrated alkali was forced to infiltrate into the micropore of chitin particles.This has accelerated the swelling of chitin,as well as the mass transfer process of NaOH,and thus form an approximate homogeneous environment of deacetylation.By controlling the degree of deacetylation of about 50%,a water-soluble chitosan(WSC) can be obtained.The apparent viscosity,FT-IR,X-ray diffraction(XRD) and differential scanning calorimetry(DSC) were applied to estimate the structure and properties of WSC.The results showed that water-soluble chitosan and the traditional chitosan have no essential difference.The difference is that the WSC prepared with forced penetration method has more amorphous structure,weakened intermolecular hydrogen bonds and good water solubility.