Water Stability of Syndiotactic Poly(vinyl alcohol)/lodine Complex Film

摘要

The desorption behavior of iodine in syndiotactic poly(vinyl alcohol) (s-PVA) with a syndiotactic diad content of 63 1% iodine film in water was investigated in relation to the solubility of s-PVA in water. Despite a low number-average degree of polymerization of 900, the degree of solubility of s-PVA film in water at 80 deg C was limited to about 10%, whereas atactic poly(vinyl alcohol) (#alpha#-PVA) film was completely soluble at a lower temperature, 50 deg C. The degree of iodine desorption of s-PVA/iodine film at a high temperature decreased remarkably compared with that of #alpha#-PVA/iodine film. The fastness of iodine of the drawn s-PVA/iodine film was far superior to that of the undrawn film. Over a draw ratio of 5, the iodine desorption was suppressed significantly with increasing drawing temperature rather than the draw ratio. In addition, the iodine desorption of postdrawn s-PVA/iodine film was lower than that of predrawn s-PVA/iodine film.