DIELECTRIC-RELAXATION BEHAVIOR OF ETHYL-METHACRYLATE AND VINYL-ACETATE GRAFTED POLY[TETRAFLUOROETHYLENE-CO-(PERFLUOROVINYL ETHER)] FILMS PREPARED BY DIRECT-RADIATION GRAFTING METHOD

Dielectric relaxation of poly(tetrafluoroethylene-co-perfluorovinyl et her) (PFA) grafted by ethyl methacrylate (EMA) and vinyl acetate (VAc) of different compositions prepared by direct radiation was studied at 0.1, 1, 10, and 100 kHz between 273 and 550 K. Two well resolved rela xation peaks are observed in all films except that with EMA/VAc of com positon 10/90 wt% in which the second peak is masked. In PFA film graf ted by EMA/VAc of 50/50 wt% at low temperature the third relaxation wa s observed. The activation energy for the relaxation was determined fr om Arrhenius plots. The ac conductivity of the films was investigated and the activation energy of conduction was evaluated. X-Ray diffracti on patterns and IR spectra were also measured.