Structure formation and depolarization relaxation processes in porous piezoactive polyvinylidene fluoride films

Piezoactive porous polyvinylidene fluoride films prepared in the process based on melt extrusion with subsequent isometric annealing, uniaxial extension and thermal fixation have been studied. It was shown that two competing orientation processes -polymorphous transition of non-polar α-phase into polar piezoactive β-phase formation structure - occur during annealed films. has established degree extruded is key factor determining efficiency both processes. Thermally stimulated depolarization method used to investigate dipole relaxation oriented films, activation energy these found. The were polarized using corona discharge high-voltage contact methods, both, dependence piezoelectric modulus polarization conditions obtained. maximum value d 31 =30.1 pC/N achieved by method. Keywords: fluoride, supramolecular structure, properties, polarization,