用固体核磁共振研究热失水壳聚糖的结构变化  

A STUDY ON STRUCTURE OF THERMALLY DEHYDRATED CHITOSAN BY SOLID STATE NMR TECHNIQUES

作　　者：赵晓东[1] 孙平川[1] 马建标[1] 

机构地区：[1]南开大学高分子化学研究所吸附与分离功能高分子材料国家重点实验室,天津300071

出　　处：《南开大学学报（自然科学版）》2001年第3期81-85,共5页Acta Scientiarum Naturalium Universitatis Nankaiensis

基　　金：国家自然科学基金 (5 9773 0 2 1 )

摘　　要：用 1 3C CP/MASNMR方法通过测定 1 3C的弛豫时间 (T1 )和旋转坐标系下 1 H的弛豫时间 (T1ρ)研究了壳聚糖热处理前后的结构变化 ,结果发现与含水壳聚糖相比 ,热失水壳聚糖所有位置的碳的弛豫时间均延长 ,在三个无水壳聚糖样品中 C2 ,6 的 T1 值依次升高 ,表明了与 C2 相连的氨基和与 C6 相连的羟基的运动受到了束缚 ,这是由于氨基与羟基之间形成氢键所致 .分子链排列的规整性增加 ,大分子之间的作用力增强 ,导致了热处理后壳聚糖溶解速度下降 .Chitosan is a biocompatible biomaterial soluble in dilute acids. After Chitosan was thermally dehydrated, its solubility was diminished obviously, suggesting that structure of chitosan was changed. The relaxation time T 1 of 13 C NMR and T 1ρ of 1H NMR singles for thermally dehydrated chitosan samples were measured by solid state CP/MAS NMR techniques, To characterize the structure change of chitosan samples before and after thermal treatment. The results showed that the relaxation times of 13 C NMR singles at every position prolonged for all thermally dehydrated chitosan samples. T 1 value of C 2,6 increased of thermal treatment time, indicating that the motion of amino grop on C 2 and hydroxy group on C 6 was probilited because of hydrogen bonds. The more regular arrangement of polymeric chains in thermally dehydrated chitosan resulted in more interaction among polymeric chains so that solubility of chitosan samples deceased after thermal treatment.

关 键 词：固体核磁共振 壳聚糖 弛豫时间 热失水 分子结构 溶解速度 加热时间 

分 类 号：O636.1[理学—高分子化学]