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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.
A series of chitosan unsaturated carboxylates, chitosan salicylate (a1), chitosan benzoate (a2), chitosan cinnamate (a3) Polysaccharide acrylate (a4) and chitosan itaconate (a5). The structure of the product was characterized by FTIR and UV spectra and the amount of carboxylic acid was determined by Kjeldahl method.The results showed that the chitosan And unsaturated carboxylate salt is formed by the carboxyl group in the amino and chitosan on the chitosan, the binding amount of carboxylic acid is between 40% ~ 70% .Using a polarizing microscope, the chitosan is not saturated The results showed that the conformal fractal crystals naturally formed at 25 ℃ and relative humidity of 65% under the environment of 25 ℃ and a5, the morphologies of the crystals were similar to that of chitosan carboxylic acid Salt structure is closely related to a2 fractal crystals, polymer chains along the long axis of the crystal arrangement, and a5 fractal crystals, the polymer chain is the vertical and long axis direction.Studies on the control of unsaturated chitosan Carboxylate aggregation behavior of the method to achieve in the accumulation of film and growth to become a high degree of conversion between crystals.Using fractal theory of chitosan The crystallization process of the unsaturated carboxylates is explained, indicating that their aggregation behavior follows the diffusions-limited aggregation model.