柠檬酸交联处理对壳聚糖纤维的增强作用

Effect of cross-linking treatment with citric acid on enhancement of chitosan fiber

为解决纯壳聚糖纤维力学性能较差的问题,文章采用柠檬酸溶液进行交联处理,探讨了交联处理条件(柠檬酸溶液质量分数、pH值、温度、时间)对壳聚糖纤维力学性能的影响。结果表明,在柠檬酸溶液质量分数20%、pH 6、交联温度50℃、交联时间2.5 h时,纤维力学性能达到最佳,干态断裂强度提高了36.36%,干态断裂伸长率提高了31%;湿态断裂强度提高了39.81%,湿态断裂伸长率提高了31%。通过对处理前后壳聚糖纤维自由氨基量与红外吸收光谱图的变化分析,表明柠檬酸与壳聚糖上的氨基产生离子交联和化学交联,从而提高了壳聚糖纤维的力学性能。

In order to improve the mechanical properties of pure chitosan fiber,citric acid solution was used for cross-linking treatment,and the effects of cross-linking treatment conditions(including mass fraction of citric acid solution,pH,temperature,and time)on mechanical properties of chitosan fibers were studied.The results showed that the fiber had the best tensile properties under the following conditions:mass fraction of citric acid solution 20%,pH 6,cross-linking temperature 50℃and cross-linking time 2.5 h.Meanwhile,the dry breaking strength and breaking elongation increased by 36.36%and 31%respectively,while the wet breaking strength and breaking elongation of chitosan fiber increased by 39.81%and 31%respectively.By analyzing the changes of the free amino groups and FTIR spectra of chitosan fibers before and after the treatment,it was found that the ionic cross-linking and chemical cross-linking were generated between the amino groups of chitosan and citric acid,and therefore the mechanical properties of chitosan fibers improved.