氧化降解壳聚糖铜配合物制备低聚壳聚糖  

Low Molecular Weight Chitosan Prepared from Oxidative Degradation of Chitosan-Cu(Ⅱ) Complex

作　　者：尹学琼[1] 袁文[2] 林强[1] 谭月鹏[2] 张岐[1] 

机构地区：[1]教育部热带生物资源重点实验室 [2]海南大学化工系

出　　处：《应用化学》2006年第7期729-733,共5页Chinese Journal of Applied Chemistry

基　　金：国家自然科学基金(20061001);海南省自然科学基金(20304)资助项目

摘　　要：经液态均相络合反应制得壳聚糖铜配合物,经IR、DTA及XRD检测,结果显示,N—H、C—N、C—O—C的红外特征峰发生移动;壳聚糖分子链断裂引起的放热峰由壳聚糖的358℃降至壳聚糖铜配合物的285℃,壳聚糖在2θ为9.83°、10.58°、19.78°、22.45°和27.71°的X射线衍射特征峰在壳聚糖铜配合物的WAXD中消失,证明壳聚糖与铜离子发生了配位作用,且配合物存在易与氧化剂作用的非晶相结构和易于断裂的壳聚糖高分子链结构。以H2O2对壳聚糖-Cu(Ⅱ)配合物及壳聚糖进行氧化降解,壳聚糖铜配合物的降解速度明显高于壳聚糖,反应2 h,壳聚糖铜配合物粘度下降率为82.9%,而壳聚糖体系粘度下降率为16.6%;且降解产物分子量分布较壳聚糖直接降解窄。壳聚糖铜配合物降解反应动力学研究表明,壳聚糖铜配合物对H2O2分解存在催化作用。降解产物脱金属处理后,所得低聚壳聚糖含铜量<1×10-6mol/L。Complex of chitosan and Cu （ Ⅱ ） （CTS-Cu） was prepared through homogenous liquid coordination. IR, DTA, and XRD analysis were utilized to determine the structure of the complex. IR peaks of N-H, C-N, and C-O-C are red shifted. The exothermal peak of chitosan chain fragmentation decreased from 358℃ of chitosan to 285℃ of CTS-Cu. XRD peaks of chitosan located at 9.83°, 10.58°, 19.78°, 22.45°, and 27.71° were absence in CTS-Cu＇s diffraction pattern. These results showed that there were coordinating bonds between chitosan and Cu （ Ⅱ ）, and CTS-Cu contained more amorphous domains which allowed a better accessibility to reactants and thus a better reactivity. On the other hand there are some coordinating bonds within CTS-Cu that are easy to be broken. H2O2 was used to degrade CTS-Cu and chitosan. Under the same conditions, the degradative velocity of CTS-Cu was faster than that of chitosan, and the degraded molecular distribution of the former case was much narrower than that of the latter. After chitosan degrading for 2 h, the viscocity of CTS-Cu decreased 82.9%, while chitosan just decreased 16.6% in terms of viscosity. Dynamics of CTS-Cu degradation showed CTS-Cu could catalyze H2O2 decomposition. After elimination, the content of copper in low molecular weight chitosan could be less than 1.0μmol/L.

关 键 词：壳聚糖铜配合物 壳聚糖 氧化降解 催化 

分 类 号：O636[理学—高分子化学]