Kinetics of PVDF film degradation under electron bombardment

A dose effect of high-energy (20 keV) electron irradiation on the chemical composition of PVDF films has been revealed using a scanning electron microscope Jeol JSM-7001F equipped with an X-ray fluorescence spectrometer Oxford INCA X-max 80. All the experimental series have demonstrated similar decreasing dependence of relative atomic fluorine content (F/C) upon the electron irradiation dose. The final non-zero F/C ratio can be explained in terms of primary defects in the original PVDF and secondary ones arising during irradiation. In general a defluorination process is consistent to a Le Moël model of PVDF degradation and can be satisfactorily described with a third-order kinetic equation, parameters of which depend on the type of a PVDF film.