壳聚糖及丁二酸酐酰化壳聚糖双氧水降解行为的研究

在简单均相体系下．研究了壳聚糖及丁二酸酐酰化壳聚糖在双氧水中的降解特性。采用鸟氏粘度计，利用一点法测量了降解过程中壳聚糖及丁二酸酐酰化壳聚糖的分子量，讨论了该体系下壳聚糖及丁二酸酐酰化壳聚糖的降解速率．通过红外光谱分析了双氧水对低分子量壳聚糖和低分子量丁二酸酐酰化壳聚糖结构的影响。结果表明．在该体系下·壳聚糖及丁二酸酐酰化壳聚糖的降解主要发生在反应开始后的2～3h内．此后降解产物的分子量逐渐趋于20000；相同条件下，丁二酸酐酰化壳聚糖的降解程度高于壳聚糖；红外光谱表明．采用该降解体系制备的降解产物主链结构基本没有发生变化。

Study on Degradation of Chitosan and Butanedioic Anhydride Acetylated Chitosan by Hydrogen Peroxide

The low molecular weight chitosan and butanedioic anhydride acetylated chitosan under the sim- ple homogeneous system with the existence of hydrogen peroxide were prepared in this article. Ubbelohde vis- cometer and ＂one point theory＂ were used to determine the molecular weight of chitosan and butanedioic an- hydride acetylated chitosan, the degradation speeds of chitosan and butanedioic anhydride acetylated were dis- cussed,and FTIR was choosed to characterize the structure of the low molecular weight chitosan and butanedio- ic anhydride acetylated ehitosan. The results proved that the degradation of chitosan and butanedioic anhydride acetylated ehitosan under the hydrogen peroxide system mainly occured in the 2~3 h from the beginning,then the molecular weight of degraded products approached 20 000 at last. FTIR Result showed that the degraded ch- itosan and butanedioic anhydride acetylated chitosan had no apparent changes in structure compared with the one before degradation.