COMPOSITE POLYAMIDES DEPOLARIZATION (TSD) AND POLARIZATION (TSP) CURRENTS

Studies on Thermally Stimulated Depolarization (TSD) and Polarization (TSP) current studies in composite polyamides are presented in this pa per. The influence of poling electric fields, heating rates, field pol arity, and electrode materials on both TSD and TSP currents are studie d in Nomex-Polyester-Nomex (N-P-N) composites. At temperatures lower t han 140 degrees C, TSD measurements show that the dipolar orientation with fast reacting dipoles associated with a polar side group contribu te to the current predominantly. At higher temperatures, interfacial p olarization occurs and this effect is confirmed by additional experime nts designed to separate TSD and TSP currents. Windowing polarization technique at 10 degrees C interval windows yields relaxation times whi ch increase with each temperature window and the activation energy als o increases from 1.0 eV to 1.55 eV as the temperature is increased fro m 60 degrees C to 130 degrees C. These values suggest that polarizatio n phenomena are associated with intermolecular cohesion.