Moisture effects on dielectric relaxations of poly (ɛ-caprolactone)/starch biodegradable blends: Local, interfacial and segmental.

Poly(ɛ-caprolactone)/starch biocomposites in a wide composition range were studied by thermally stimulated depolarization currents, TSDC, during the drying process following the effect on the dielectric relaxations of moisture loss and blend composition. PCL's cooperative chain mobility is unaffected by the presence of water which is mainly located in the starch inclusions as its segmental relaxation is fixed at 207K. The heterogeneities found in the amorphous phase of neat starch are also observed here as a bimodal α relaxation which shifts to higher temperatures as it dries.