Intermolecular interactions in blends of poly(vinyl alcohol) with poly(acrylic acid) .2. Correlation between the states of sorbed water and the interactions in homopolymers and their blends

Water-polymer interactions have been studied by d.s.c. and FTi.r. in water vapour-saturated poly(vinyl alcohol), poly(acrylic acid) and their blends before and after thermal treatment (0.5h at 180 degrees C>. The 3600-3000 cm(-1) (OH stretching), 1800-1700 cm(-1) (C=O stretching) and 1700-1600 cm(-1) (HOH bending) regions have been used. Water-polymer and polymer-polymer interactions which are respectively formed and destroyed in the presence of water have been identified. For this purpose, subtraction of the spectrum of dry samples from the spectrum of water-saturated films has been performed. Changes in crystallinity of poly(vinyl alcohol) were also measured by FTi.r. D.s.c. has been used to confirm the strength of water-polymer interactions and to demonstrate changes in the miscibility of polymer components. Copyright (C) 1996 Elsevier Science Ltd.