Temperature dependence and correlation of polarization processes in P (VDF-HFP) films

Polymer dielectrics are indispensable in electrical and electronic systems, being used as insulation, capacitors, gate dielectric, etc. However, a lot of polymer materials show unsatisfactory efficiency at high temperature and low frequencies, which has been found to be closely related to polarization processes. In this paper, the dielectric spectroscopy of poly (vinylidene fluoride-hexafluoropropylene) (P(VDF-HFP)) films is investigated over a broad frequency range from 10 mHz to 1 MHz and temperature range from -130 degrees C to 130 degrees C based on the Dissado-Hill model. The processes in the entire response are identified and characterized quantitatively. The temperature dependence of major processes contributing to energy storage and dielectric loss are revealed. It is found that the variations of both beta polarization and DC conductance coincide with Arrhenius equation, while both alpha polarization and quasi-DC polarization show Vogel-Fulcher-Tammann (VFT) features. Moreover, alpha polarization and quasi-DC polarization share the same form parameter of VFT equation, indicating that they have a common origin of microstructure. The origin and correlation of polarization processes could be used to develop a paradigm for rational design of polymer dielectrics to enhance or suppress specific processes for certain purposes.

Automated summary

This study investigated the dielectric spectroscopy of P(VDF-HFP) films over a wide frequency and temperature range, revealing the temperature dependence and commonality among different polarization processes. The findings could be used as a paradigm for the rational design of polymer dielectrics to enhance or suppress specific polarization processes.