Homogeneous Dynamics within Inhomogeneous Environment in Semicrystalline Polymers

We show that the combination of dielectric with neutron spin echo measurements performed in a model deuterated polymer as poly(ethylene terephthalate) suggests that the dynamics of semicrystalline polymers occurs in an homogeneous scenario similar to that valid to describe the dynamics of amorphous polymers. Accordingly, the intermolecular cooperativity is expected to be rather similar in both amorphous and semicrystalline polymers. The reduced segmental mobility of the semicrystalline polymer is restricted to well differentiate regions, probably in the crystal amorphous interface. The significant broadening of the dielectric segmental relaxation in semicrystalline polymers can be attributed to the averaging effect of measuring a homogeneous relaxation with similar stretching exponents over an inhomogeneous environment.