Separate contributions to the pyroelectricity in poly(vinylidene fluoride)from the amorphous and crystalline phases, as well as from their interface

New selective poling schemes for polar semicrystalline polymers are describ ed, and appropriate poling fields and temperatures are specified. In the fo llowing investigation of the pyroelectric response and the thermally stimul ated depolarization (TSD), poly(vinylidene fluoride) is used as an example for a semicrystalline ferroelectric polymer. It is shown that the amorphous and the crystalline phase, as well as the interface between them contribut e to the pyroelectric effect. From dynamic pyroelectrical measurements and TSD experiments, the permanent polarization of the dipoles in the crystalli ne phase, the frozen-in polarization of the dipoles in the amorphous phase, and the effect of the excess charges of the Maxwell-Wagner interface polar ization can be identified. With the proposed selective poling schemes (poli ng temperatures below and/or above the glass transition temperature, as wel l as poling fields lower and/or higher than the coercive field), it is poss ible to clearly separate the respective contributions to the pyroelectric e ffect. (C) 1999 American Institute of Physics.