[en] Full text: Fluorinated polymers are characterized by their excellent resistance to chemical attack and good thermal stability. Therefore they have found applications where resistance to harsh chemical and thermal environments is a prerequisite. One such application is the use of the copolymer poly(tetrafluoro-ethylene-co-perfluoropropylene), FEP, in the manufacture of thermal blankets for space applications, where the polymer is exposed to oxygen atom, as well as electron and cosmic radiations. Another is in the manufacture of poly(tetrafluoroethylene-co-perfluoromethyl vinyl ether), TFE/PMVE, O-rings for use in the microelectronics industry where oxygen atom processing is used. For this application the copolymer is radiation crosslinked. In this paper the use of solid state '¹⁹F NMR and ESR spectroscopies for identification of new structure formation on radiolysis of fluorpolymers such as those of TFE/PMVE and FEP will be discussed and the radiation chemical yields for formation of new chemical structures will be reported. The TFE/PMVE and FEP copolymers were obtained from the Du Pont Co. and used without further purification. The TFE/PMVE copolymers had an X_TFE, of 0.66 and 0.81 and were amorphous and semi crystalline, respectively, with T_g of ∼ 276 K and molecular weights of approximately 60 kg mol^-1, while the FEP had an X_TFE of 0.90 and was semicrystalline with a T_g of 358 K. The polymer samples were irradiated as powders under vacuum in glass ampoules or ESR tubes to a range of doses over a range of temperatures using ⁶⁰Co irradiation at a dose rate of ∼ 20 kGy hr^-1. After irradiation, for NMR studies the samples were heated to above T_g to effect radical decay before being opened to the atmosphere. They were then placed in a vacuum oven at 373 K for 12 hr to remove any evolved gases. The solid state ¹⁹F NMR spectra of the unirradiated TFE/PMVE copolymers consisted of three major resonances arising from O-CF₃, -52.4 ppm; -CF₂, -110 to -120 ppm and -CF-, -130 to -136 ppm, with intensities consistent with the composition of the copolymer. Similar spectra of FEP give resonances at -CF₃, - 68 to -75 ppm; -CF₂, -110 to -130 ppm and -CF-, -183 to -187 ppm. The spectrum of TFE/PMVE following irradiation at room temperature featured increased line widths for the -OCF₃, - CF₂- and -CF- peaks, but no similar line width changes were observed for FEP at room temperature. The increase in the line widths of the TFE/PMVE peaks can be attributed to formation of a crosslinked network. The major new peaks formed in TFE/PMVE have been assigned to: -CF₂-O-CF₃*; CF₂-CF₃*; -CF₂*-O-CF₃; -CF₂*-COOH; -CF*=CF₂ and -CF₂-CF*(-CF₂-)-CF₂-. The -CF₂-COOH groups are believed to be formed by hydrolysis of new -CF₂-COF chain ends by atmospheric moisture. The major new peaks observed on irradiation of FEP were: -CF₂*-CF₃; -CF₂-CF₃*;-C R_F=C R_F-CF₃*; C R_F=CF₂*; -CF₂-C-(CF₃*)₃ and -CF₂-CF*(R_F)-CF₂-. The ESR spectra at 77 K of the radicals formed during radiolysis of TFE/PMVE and FEP copolymers are highly anisotropic. The major radicals formed have been assigned as -CF₂-CF₂^. and -CF₂-^.CR_F-CF₂- for both polymers, and are believed to be the precursors for formation of the branched structures