OXYGEN PERMEATION THROUGH FILMS OF POLYPROPYLENE HYDROGENATED OLIGOCYCLOPENTADIENE BLENDS

Oxygen permeation through films of isotactic polypropylene (iPP)/hydrogenated oligocyclopentadiene (HOCP) blends was studied as a function of the weight fraction of the two components and temperature. Increasing HOCP content lowers oxygen permeability and diffusivity through the films and increases the glass transition temperature of the polymer blends. Activation energies for permeation and diffusion processes were also measured. Annealing for 2 min at 100-degrees-C was shown to completely transform the smectic phase in the alpha-crystalline form and to induce a marked increase in oxygen permeability and diffusivity, especially in the blends, and a corresponding decrease in the activation parameters.