Abstract
Case II diffusion of dimethylsulfoxide and water (90/10 (vol%)) mixed solvent through a poly (vinyl alcohol) film at 40°C was investigated. A diffusion front was observed at the inter-face of the swollen layer and the unswollen glassy core and it was found that the motion of the diffusion front obeyed the Case II mechanism. Cracking was observed in the core at the late stages, which should induce the Super Case II process. This cracking is supposed to be caused by expansive force of the swollen layer.
