Peculiarities of the dielectric and dynamic-mechanical response in poly(vinylidene fluoride - hexafluoropropylene)

This paper discusses about dielectric relaxation spectroscopy (DRS) and dynamical-mechanical response of ferroelectric poly(vinylidene fluoride-hexafluoropropylene) P(VDF-HFP) copolymer films. Uniaxial stretching of the films with optimized stretching parameters does not significantly increase the elastic modulus at room temperature, but induces an enhanced electric polarization. The increase of polarization stems from the formation of a ferroelectric phase, an additional polarization in the amorphous phase and from melting of secondary crystallites formed in the amorphous phase by annealing or storage.