磷酸酯淀粉／PVA共混浆膜的织态结构与性能

研究了淀粉磷酸酯化变性和聚乙烯醇(PVA)结构对磷酸酯淀粉(SPH)/PVA共混浆膜织态结构与力学性能的内在联系,探讨了SPH与PVA间的共混比对浆膜结构和力学性能的影响.实验结果表明,磷酸酯化变性深度、PVA分子结构及共混比对共混浆膜的织态结构及力学性能有显著影响.随着淀粉磷酸酯化变性深度的增大,共混浆膜的断裂伸长率增大,断裂强度先增大后减小;当取代度为0.016时,断裂强度达到最大值.随着SPH质量分数的增加,共混浆膜的断裂伸长率减小,断裂强度先减小后增大;当SPH/PVA的共混比为50/50时,断裂强度达到最小值.提高PVA相对分子质量,增大醇解度,都有利于改善共混浆膜的力学强度,提高耐屈曲性能.

The Mechanical Properties and Morphological Structure of the Phosphorylated Starch-PVA Blend Film for Warp Sizing

The dependences of molecular structure of polyvinyl alcohol(PVA),modification extent of phosphorylated starch(SPH),the blending ratio of SPH to PVA on the morphological structure and mechanical properties of SPH/PVA blend film were investigated.The experimental results demonstrate that the molecular structure,modification extent,and the blending ratio show evident influences on the morphological structure and mechanical properties of the film.As the degree of substitution increases,the breaking elongation increases,while the breaking strength of the film increases initially and then decreases.A maximal strength appears when the degree of substitution is 0.016.As the content of SPH in the film rises,the breaking elongation decreases,whereas the breaking strength initially decreases and then increases.Maximal breaking strength is obtained when the blending ratio of SPH/PVA is 50/50.Increasing the molecular weight and degree of hydrolysis of PVA favors enhancing the mechanical strength and bent-fatigue resistance of the film.