Hydration Structure andRheological behavior of Aqueous Poly(vinyl alcohol) Solutions

The hydrolysis degree of poly (vinyl alcohol) and its intra and intermolecular hydrogen bonds in water-based concentrated solutions was characterized by rheological evolution of as-prepared and one week stored sample. The acetyl groupcontent was assigned as the representative of inter and intra hydrogen bonds. Strong acetyl-hydroxyl hydrogen bondsenhanced the solution viscosityand reduceditshysteresis after one week storage.The temperature-frequency conformity and the DSC results, confirmed the high observed hysteresis due to crystal formation atweak hydroxyl-hydroxylbonds leading to steep viscosity decrease in shearing.