中文摘要：

采用溶液成膜的方法制备了不同Mg（NO3）2含量的聚乙烯醇（PVA）/Mg（NO3）2复合薄膜。考察了PVA/Mg（NO3）2复合薄膜在相对湿度为54%时的含水量。采用X射线衍射（XRD）,差示扫描量热（DSC）,动态力学性能（DMA）和力学性能测试方法研究了Mg（NO3）2对PVA膜的结构和性能的影响。结果表明,Mg（NO3）2与PVA的相容性非常好,所制备的PVA/Mg（NO3）2复合膜的透明性好。Mg（NO3）2的加入能显著破坏PVA中的氢键作用,增加PVA膜中的水含量,降低PVA的结晶度,使复合膜的玻璃化温度明显降低。拉伸实验表明,PVA/Mg（NO3）2具有比纯PVA膜更低的拉伸强度和更高的断裂伸长率。

英文摘要：

Poly（vinyl alcohol）（PVA）/Mg（NO3）2 blended films were prepared by casting from the solutions containing different content Mg（NO3）2 and PVA.The water content in blended films was determined at RH of 54%.The properties of PVA/Mg（NO3）2 blended films were investigated by X-ray diffraction,differential scanning calorimetry,dynamic mechanical analysis and mechanical testing.It has been shown that the addition of Mg（NO3）2 can disrupt the inter and intra chain hydrogen bonding of the PVA chains and therefore reduce the crystallinity of PVA.The water content of PVA/Mg（NO3）2 blended films increases with the amount of Mg（NO3）2.The glass transition temperature（Tg） of PVA/Mg（NO3）2 blended films is much lower than that of pure PVA films.Mechanical testing results show that PVA/Mg（NO3）2 films are of lower tensile strength and higher elongation at break compared with PVA film.