壳聚糖不饱和羧酸盐聚集行为的研究  

AGGREGATION BEHAVIOR OF UNSATURATED CARBOXYLIC ACID SALTS OF CHITOSAN

作　　者：林宝凤[1,2] 黎演明[1] 周妤莲[1] 杜予民[2] 

机构地区：[1]广西大学化学化工学院,南宁530004 [2]武汉大学资源与环境科学学院,武汉430079

出　　处：《高分子学报》2011年第3期267-273,共7页Acta Polymerica Sinica

基　　金：国家自然科学基金(基金号50263001);广西南宁市科技攻关项目(项目号200901023A);科技部项目(项目号2009GJE10048)资助

摘　　要：以半干法制备了一系列壳聚糖不饱和羧酸盐———壳聚糖水杨酸盐(a1)、壳聚糖苯甲酸盐(a2)、壳聚糖肉桂酸盐(a3)壳聚糖丙烯酸盐(a4)和壳聚糖衣康酸盐(a5).用红外光谱和紫外光谱表征了该产品的结构,以凯氏定氮法测定了羧酸的结合量.结果表明壳聚糖和不饱和羧酸盐是通过壳聚糖上的氨基和羧酸中的羧基发生了成盐反应,羧酸的结合量在40%～70%之间.用偏光显微镜研究了壳聚糖不饱和羧酸盐的结晶形貌.结果发现,a2和a5的浓溶液浇铸膜在25℃和相对湿度为65%的环境下,可自然形成规整的分形晶体,晶体的形貌与壳聚糖羧酸盐的结构密切关联.对于a2的分形晶体,高分子链是沿着晶体的长轴方向排列,而对于a5的分形晶体,高分子链是垂直与长轴方向.研究了控制壳聚糖不饱和羧酸盐聚集行为的方法,实现了在聚集成膜与生长成为高度结晶体间的转换.用分形理论对壳聚糖不饱和羧酸盐的结晶过程进行了解释,说明其聚集行为遵循扩散限制聚集(diffusions-limited aggregation)模型.Five kinds of unsaturated carboxylic acid salts of chitosan were prepared by the semidry wayincluding chitosan salieylatc （ al ） , chitosan benzoate （a2） , ehitosan cinnamate （ a3 ） , ehitosan acrylate （a4） and chitosan itaconate （ a5 ）. The products were characterized via FTIR and UV,the content of earboxylic acid in the unsaturated carboxylic acid salt of chitosan was determinated by the Kjeldahl method. The results showed that unsaturated carboxylic acid salts of chitosan were combined with salt bond between amino and carboxyl, the content of earboxylic acid in the unsaturated carboxylic acid salts was ranged from 40% to 70%. The crystalline morphology of these unsaturated carboxylic acid salts of ehitosan were obtained by polarized optical microscopy. The results showed that the films of a2 and a5 obtained by a casting solvent vaporation technique had formed fractal crystal at 25℃ and RH = 65%. The crystalline morphology was closely related to the structures of unsaturated carboxylic acid salts of chitosan. The fractal crystal of a2 showed that the extended molecular chains were parallel to the long axis. The fractal crystal of a5 showed that the extended molecular chains were perpendicular to the long axis. The methods for controlling aggregation behavior of unsaturated carboxylic acid salts of chitosan had also been studied. It was feasible for the inter-conversion between aggregation and crystallization. The crystallization process of chitosan unsaturated carboxylic acid salts was explained by fractal theory, and the results showed that its aggregation behavior abide by the model of diffusions-limited aggregation.

关 键 词：壳聚糖不饱和羧酸盐 结晶形态 聚集行为 分形理论 

分 类 号：O631.3[理学—高分子化学]