Combined Effects of Heat Treatment and Plasticizers on Polyvinyl Alcohol Films.

The effects of heat treatment on PVA films containing water soluble plasticizers were investigated. Propylene glycol, glycerol and polyethylene glycol were used as plasticizers. There was synergism between heat treatment and the presence of plasticizers in enhancing the water resistance of PVA films. In the absence of heat treatment, however, the plasticizers increased the aqueous solubility of PVA films. The plasticized films further showed a lower permeability to propranolol HC1 compared to the unplasticized films following heat treatment.