Characterization of poly(vinyl alcohol) films with various molecular parameters

The effects of three major molecular parameters of poly(vinyl alcohol)—the number‐average degree of polymerization, degree of saponification, and syndiotactic dyad content—on the characteristics of poly(vinyl alcohol) films were investigated. Various poly(vinyl alcohol) films were prepared by a casting method. Then, the films were characterized with atomic force microscopy, differential scanning calorimetry, wide‐angle X‐ray diffraction, Fourier transform infrared spectroscopy, and Instron instrumentation. On the basis of atomic force microscopy images and calculated average roughness values, it was determined that the surface roughness of poly(vinyl alcohol) films increased with increasing molecular parameters. The crystallinities obtained with differential scanning calorimetry and wide‐angle X‐ray diffraction analyses were also enhanced with increasing molecular parameters, especially the degree of saponification. The tensile properties were improved with higher molecular parameters. This might be ascribed to the fact that the higher the molecular parameters were, the stronger the hydrogen bonding was. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007