硼酸交联对挤出吹塑变性淀粉/聚乙烯醇复合膜性能的影响

摘要

为了提高淀粉基复合膜的阻水性,拓宽淀粉膜的应用范围,以羟丙基二淀粉磷酸酯与聚乙烯醇(PVA)为成膜原料,硼酸为交联剂,采用挤出吹塑工艺制备了淀粉/PVA复合膜.分析了粒料的流变性能,研究了淀粉膜的交联密度、力学性能、阻隔性能、疏水性能以及微观形貌等性质.结果表明,随着硼酸添加量的增加,淀粉/PVA复合材料的熔体流动性下降,淀粉/PVA复合膜的阻氧、阻水性能增强,而淀粉膜的抗拉强度和拉伸模量呈降低趋势,断裂伸长率先升高后降低.添加1％的硼酸,淀粉/PVA复合膜的表面更加均匀平整,疏水性最强,具有最小的溶胀度、最大的凝胶质量和最高的交联密度.%To improve the water vapor barrier properties of starch-based composite films,and further expand their application,hydroxypropyl distarch phosphate and polyvinyl alcohol (PVA) were selected as film forming materials,and boric acid as crosslinking agent.The starch/PVA composite films were prepared by extrusion film blowing in this study.The rheological properties of pellets were analyzed,and the crosslinking density,mechanical properties,barrier properties,hydrophobic properties and microstructure of the films were also studied.The results showed that the melt fluidity of starch/PVA composites decreased,while the oxygen and water vapor barrier properties enhanced,but the tensile strength and tensile modulus decreased and the elongation at break increased first and then decreased accompanied with the increase of boric acid content.The starch/PVA composite film with 1％ boric acid had more uniform and smooth surface,the strongest hydrophobic property as well as the smallest swelling degree,the largest gel mass and the highest crosslinking density.