Crystal structures and viscoelastic behavior in different morphologies of a vinyl alcohol-ethylene copolymer

Different morphological structures of a vinyl alcohol-ethylene copolymer wi th high content (72 mol%) in the former counit are obtained by various phys ical and chemical routes (annealing, stretching, and residual content of un hydrolyzed acetate groups). The specimens thus obtained are studied by X-Ra y diffraction, differential scanning calorimetry and dynamic mechanical ana lysis in order to show the influence of the chemical, thermal, and mechanic al histories on the crystalline structure, thermal properties and viscoelas tic motions of the vinyl alcohol-ethylene copolymer.