Some Physical Properties of Humidified Polyvinyl Alcohol Films

Abstract

Electrical volume resistivity and dynamic mechanical properties of fractionated PVA films, which absorbed water in various relative humidities at 20°C, have been measured. It is shown that there is a transition range in physical properties of humidified PVA films at round 10% water content. This suggests the nature of absorbed water in PVA films.
It is found that the dynamic mechanical properties of PVA films are not affected by after heat-treatment, that is, not related to the degree of crystallinity but depend on absorbed water content.
The water content dependence of dynamic mechanical properties is similar to the temperature dependence, the former being more remarkable in comparison with the latter.