PVA与超高摩尔质量PEO复合膜的制备及表征

Preparation and characterization of PVA-ultra-high molecular weight PEO blend films

将聚乙烯醇(PVA)与超高摩尔质量的聚氧化乙烯(PEO)进行共混,制备了PVA-PEO复合膜,并对混合溶液的流变行为、力学性能及其结晶行为进行了考察.研究发现:PVA水溶液及PVA-PEO混合溶液的稳态流变行为均呈现明显的第一牛顿区、非牛顿区和第二牛顿区.少量PEO的加入使混合溶液的黏度增大,但增加幅度不大;PEO加入后得到的PVA-PEO复合膜的弹性模量、断裂强度及断裂伸长率等力学性能及玻璃化温度均有所提高,且随着PEO质量分数的提高,各项力学性能均得到增强,这与在成膜过程中PEO的加入使PVA的晶区尺寸变小而分布均匀,以及体系中物理交联点增加有关.

Poly vinyl alcohol （PVA） and ultra-high mass weight poly ethylene oxide （PEO） were blended to prepare PVA-PEO blend films. The rheological behavior of the mixed solution, the mechanical properties and crystalline behavior of the blend films were investigated in detail. The steady shear curves of both PVA solution and PVA-PEO mixed solution could be divided into three regions. The viscosity of PVA-PEO mixed solution increase slightly with the introduction of PEO. The results indicated that the elasticity modulus, strength and elongation at break of the films were improved after adding a small amount of ultra-high mass weight PEO and increased with the increase of PEO content. Although the introduction of PEO caused a decline in the crystallinity of PVA, the size of crystalline region of PVA decreased and distributed uniformly. It is believed that the small and uniformly dispersed crystalline regions in fact increase the number of physical crosslinking points and lead to the enhancement of those mechanical performances as well as the glass transition temperature for the blend films.