Effects of radiation crosslinking on electrical properties of tetrafluoroethylene-ethylene copolymer

We investigated the effects of fast electron irradiation on electrical properties of tetrafluoroethylene-ethylene copolymer (F40) and measured volume resistivity /spl rho//sub V/, dielectric loss angle tg/spl delta/, permittivity /spl epsi//sub r/ and breakdown strength E/sub B/, before and after irradiation. We found that /spl rho//sub V/ and tg/spl delta/ seriously varied with radiation. /spl rho//sub V/ decreased by two orders of magnitude after irradiation, and slowly recovered with the storage time at room temperature. Howwhile, /spl epsi//sub r/ and E/sub B/ are unchanged. We think that the variation of /spl rho//sub V/ and tg/spl delta/ are due to trapped carriers and space charge in irradiated F40. Studies on radiation crosslinking of F40 have been reported, but effects of fast electron irradiation on electric properties of F40 have not yet been reported. This paper gives our results for the variations in volume resistivity /spl rho//sub V/, loss tangent tg/spl delta/, relative permittivity /spl epsi//sub r/ and dielectric breakdown strength E/sub B/ of F40 after fast electron irradiation, and the variations of irradiated F40 electrical properties with standing time at room temperature have been observed dynamically. >