Change of molecular motion of polytetrafluoroethylene (PTFE) by radiation induced crosslinking

Electron beam irradiation of polytetrafluoroethylene in vacuum at elevated temperature: An infrared spectroscopic study

“…We note that results published recently by Oshima et al 5,[7][8][9][10] and Tabata et al 6 indicate branching and crosslinking of PTFE by irradiation under similar conditions. Of course, the possibility that branches with side chains longer than the CF 3 group or crosslinked structures are formed by irradiation of molten PTFE cannot be ruled out.…”

“…3 Recently, it was found that PTFE is crosslinked by ionizing radiation under specific conditions: irradiation in an oxygen-free atmosphere at approximately 340°C; that is, a temperature just above the melting point of PTFE. 4 -10 This crosslinking was assumed because the yield strength and modulus increase, 5 the heat of crystallization decreases with increasing radiation dose, 5 unirradiated white-colored PTFE sheets become transparent due to reduced crystallinity, 7 the mode of molecular motions changes, 6,8 and the radiation resistance is much improved. 6,7 We investigated the irradiation of PTFE under the aforementioned conditions using the electron beam facility in our institute.…”

The Influence of the Irradiation Temperature on the Ratio of Chain Scission to Branching Reactions in Electron Beam Irradiated Polytetrafluoroethylene (PTFE)

“…[4] A few years ago, it was demonstrated that PTFE can be crosslinked by irradiation in its molten state in an oxygenfree atmosphere. [5,6] The crosslinking was assumed because the yield strength and modulus increase, [6] the heat of crystallization decreases on increasing radiation dose, [6] non-irradiated white-colored PTFE sheets become transparent due to reduced crystallinity, [7] the mode of molecular motions changes, [8,9] and the radiation resistance is…”

Synthesis and characterization of PEFC membranes based on fluorinated-polymer-alloy using pre-soft-EB grafting method

“…According to dynamic mechanical analysis, the a-relaxation temperature (T a ) of RX-PTFE has not changed so much even if the network densities are different [24], and T a s showed about 110-130°C. T a of main chain such as RX-PTFE and RX-FA are higher than T g (ca.…”