Effect of chemical interactions in the metal–F system on the electric properties of fluoroelastomers

The characteristics of low-frequency dielectric relaxation at high temperatures in poly(vinylidene fluoride) (PVDF) and copolymers of VDF with hexafluoropropylene HFP are discussed; this relaxation is localised near the melting temperatures, characterised by a giant strength of relaxation and attributed to the accumulation of spatial charge (presumably H⁺ and F) at electrode boundaries. For Al electrode, dispersion is controlled by the concentration of CF₃ groups in the polymer; this fact should be related to formation of specific fluorine-aluminium compounds and the capacitance of the double electric layer is considerably controlled by formation of AlF₃ groups at the boundary of the polymer melt with the electrode.