壳聚糖-淀粉-苯甲酸钠三元共混膜的结构和性能

以溶液共混法制备了壳聚糖-淀粉-苯甲酸钠三元共混膜，通过红外光谱(FT-IR)，X-射线衍射(XRD)，扫描电镜(SEM)，透过率(T)表征了其结构，同时测试了其吸水率(Q)、力学性能及抗菌性能．结果表明，当壳聚糖含量为80％时，共混膜的湿态抗张强度(σw)和干态断裂伸长率(εd)均达到最大值；而壳聚糖含量为60％时，共混膜的干态抗张强度(σd)和湿态断裂伸长率(εw)均达到最大值．苯甲酸钠的加入仅对共混膜的σw有一定程度的增强，主要是提高了其抗菌性，且苯环的引入还可以降低膜的吸水性．同时也发现温度的升高对共混膜的σw的影响并不明显，但εw得到很显著的提高。

Structures and Properties of Chitosan-Starch-Sodium Benzoate Blend Films

The chitosan-starch-sodium benzoate blend films were prepared by solution method, and then characterized by FT-IR, XRD, transmittancy, percent water absorption, measurement of mechanical properties and antimicrobial activity. The results suggested that there was some strong interaction and good compatibility in the blend films. The starch content in the blend films can improve the mechanical properties of them, the tensile strength values increased by 31.9% in dry state and 26.4% in wet state when the chitosan content was 60%. The antimicrobial activity of blend films increased as sodium benzoate was added to the films, In one week, the antimicrobial activity against St.aureus and E.coli of the blend films increased by 10.4% and 31.2% each when the chitosan content was 80%.