Effect of shear rheology on PVDC and PE blend permeation behavior

The morphology of an immiscible polymer blend is dependent on the flow properties of the components and the deformation fields to which the mixture is exposed. The barrier properties of an immiscible blend is dependent on the barrier properties of the components and the morphological structure of the blend. Therefore, the resulting permeation rate of these blends is dependent on the rheology of the component materials. Conversely, the morphology of these blends can be studied by measuring permeation rates of a probe molecule. The oxygen permeation rate of vinylidenechloride copolymers blended with polyethylene changes abruptly over a small composition range. In the absence of significant extensional flow fields, this change is due to a phase inversion, and its position in the composition range is dependent on the shear rheology of the components.