Maxwell's law and a model to calculate the permeability coefficient of a biphasic system with lamellar morphology were used to describe the transport properties of the TPU/EVOH blends.

The experimental permeability values were compared with those obtained from Maxwell's law (Eq.

where [P.sub.b,M], [P.sub.c], and [P.sub.d] are the permeabilities of the blend as calculated by Maxwell's law (Eq.

[P.sub.b], [P.sub.b,M], [P.sub.b,L], and [P.sub.TPU] are the experimental permeability coefficient of the blend, the permeability coefficient of the blend calculated using Maxwell's law, the permeability coefficient of the blend calculated using the model used to calculate the permeability coefficient of the biphasic system with the lamellar morphology, and the permeability coefficient of pure TPU, respectively.