Polarization phenomena in blends of polyurethane and styrene-acrylonitrile

Abstract

Dielectric measurements, by means of thermally stimulated depolarization currents (TSDC), ramp voltage and reverse I-V characteristics, were used to study molecular mobility and polarization phenomena in blends of thermoplastic polyurethane (TPU) and styrene-acrylonitrile copolymer (SAN) with different SAN contents. We observed a plasticization action of SAN content on secondary /spl gamma/, /spl beta/ and primary /spl alpha/ relaxation of TPU rich phase of the blends. The heterocharge relaxation observed in the high temperature region of TSDC thermograms shifts to lower temperatures with increasing TPU content in the blends. From reverse I-V characteristics we calculated the carrier mobility, which was found to follow Arrhenius behavior, as well as the activation energy of the mechanism.