中文摘要：

壳聚糖目前是天然可降解医用材料的研究热点,但因脱乙酰度（D.D.）为60%~80%的壳聚糖难于制备,国内外对不同脱乙酰度壳聚糖的生物相容性研究少见报导。探索了不同脱乙酰度壳聚糖的制备工艺及D.D.对壳聚糖结构和性能的影响,为进一步研究不同脱乙酰度壳聚糖降解产物对内皮细胞行为的影响做准备。方法：以高脱乙酰度壳聚糖为原料制备中、低脱乙酰度壳聚糖,用酸碱滴定法测定D.D.,粘度法测定分子量,傅利叶红外光谱和X射线衍射法分析晶体结构。结果：制备得到的壳聚糖D.D.分别为54%、61%、63%、70%、80%;D.D.降低使壳聚糖分子量增加,结晶度降低,水溶性和成膜性能改善。表明在乙酰化反应中控制均相条件和乙酸酐用量,能解决D.D.在60%~80%间的壳聚糖难制备的问题。

英文摘要：

The research on chitosan as the natural degradable medical material is popular. However,the research on the biocompatibility of chitosan with different Degree of Deacetylation （D. D. ） was little reported because of the difficult preparation of chitosan with D. D. from 60% to 80%. The preparation technique of chitosan with different D. D. and the effect of different D. D. on structure and ability of chitosan were studied in this article. This article is to support further research on the effect of degradation products from chitosan with different D. D. on the behavior of endodermis cell. The chitosan with middle and low D. D. was prepared by N-acetylated reaction of chitosan with high D. D. , the D. D. of chitosan was measured by acid-base titration method,the molecular weight was measured by viscosity method, and the crystallization was analyzed by FTIR and XRD. The result show that the D. D. of prepared chitosan was 54 %, 61%, 63 %, 70%, 80 % and the decrease in D. D. resulted in the increase in molecular weight, the decrease in crystallinity,the improvement in water-solubility and membrane ability. The problem on the preparation of chitosan with D. D. from 60% to 80 % can be solved by controlling the homogeneous condition and the dosage of acetic anhydride in N-acetylated reaction.