醋酸酯淀粉/聚乙烯醇共混膜形态结构与性能

Morphological Structure and Mechanical Properties of an Acetylated Starch-PVA Blend Film

以溶液共混法制备了醋酸酯淀粉(SA)/聚乙烯醇(PVA)共混膜,通过扫描电镜(SEM)观测其表面形貌、X射线衍射仪(XRD)表征其结构、Zwick强力仪测试其力学性能.结果表明,醋酸酯化变性及SA与PVA之间的共混比对共混膜的形态结构及力学性能均有影响.随着淀粉醋酸酯化变性程度的增大,共混膜的断裂伸长率增大;当变性取代度达到0.035之后,断裂强度明显增大.增加SA的质量分数,共混膜的断裂伸长率减小,断裂强度先降低后增大;当共混比为50∶50时,断裂强度最小.

A novel starch acetate （SA）/polyvinyl alcohol （PVA） blend film was prepared by solution mixing. The morphology, structure, and mechanical properties of the blend film were characterized and measured with SEM, XRD and Zwick Material Tester. The acetylation as well as the blending ratio between SA and PVA shows evident influences on the morphological structure and mechanical properties of the blemd film. With the increase in the degree of substitution of starch acetate, the breaking elongation of the film increases. The tensile strength of the film enhanced evidently when the degree of substitution reaches and exceeds 0. 035. As the ratio increases, the breaking elongation decreases whereas the tensile strength initially decreases and then increases. The lowest strength is observed when the ratio is 50%.