Surface Properties of a Novel Poly(vinyl alcohol) Film Prepared by Heterogeneous Saponification of Poly(vinyl acetate) Film

Almost general poly(vinyl alcohol) (PVA) films were prepared by the processing of a PVA solution. For the first time, a novel poly(vinyl alcohol) (PVA) film was prepared by the saponification of a poly(vinyl acetate) (PVAc) film in a heterogenous medium. Under the same saponification conditions, the influence of saponification time on the degree of saponification (DS) was studied for the preparation of the saponified PVA film, and it was found that the DS varied with time. Optical microscopy was used to confirm the characteristics and surface morphology of the saponified PVA film, revealing unusual black globules in the film structure. The contact angle of the films was measured to study the surface properties, and the results showed that the saponified PVA film had a higher contact angle than the general PVA film. To confirm the transformation of the PVAc film to the PVA film, 1H nuclear magnetic resonance spectroscopy, X-ray diffraction measurements, differential scanning calorimetry, and Fourier-transform infrared spectroscopy were employed.