The role of the electret effect in the formation of the piezoelectric state in polyvinylidene fluoride-tetrafluoroethylene copolymer films

In this work, the phenomenon of polarization of polyvinylidene fluoride-tetrafluoroethylene copolymer (P(VDF-TFE)) polymer films in the field of a corona discharge at elevated temperatures has been studied in order to elucidate the mechanism of formation of the piezoelectric state. The TSD spectroscopy was used to analyze the charge accumulation and relaxation processes occurring in the (P(VDF-TFE)) films during polarization. The results obtained made it possible to reveal an interrelationship of forming the electret and piezoelectric states in the (P(VDF-TFE)) as well as to explain the mentioned mechanism. On this basis a polarization procedure in the field of the corona discharge was developed and tested. This procedure permitted reducing the probability of electrical breakdown leading to mechanical damage of the films and allowed improving key characteristics of the objects under question.