Rheological parameters’ effect on the electret properties of polyvinylidene fluoride

It is known that polymer films based on a copolymer of polyvinylidene fluoride and tetrafluoroethylene P(VDF-TFE) have piezoelectric properties, and these properties appear only after preliminary stretching of the films. The polar crystalline β-phase of the copolymer is responsible for the piezoelectric properties in the P(VDF-TFE), the percentage of this phase in the polymer can vary. In this work, we have studied the influence of the orientational stretching rate on the stability of the electret, and, as a consequence, the piezoelectric state. The influence of rheological parameters on the polymer structure and the parameters of electrically active defects responsible for polarization processes is shown.