A differential scanning calorimetry study of polyvinyl alcohol

Polyvinyl alcohol samples prepared by radical polymerization of vinyl acetate in methanol solution and having different MM and different acetate group contents are studied by a DSC method. With increase in the number of acetate groups the proportion of crystalline phase and the melting point, and also the quantity of water bound in the polyvinyl alcohol, which attains 2 wt% under 80% humidity conditions, are significantly decreased. Moreover, half the water is in the strongly bonded state, and enters preferentially into the polymer crystal lattice.