Radiation-induced branching and crosslinking of poly(tetrafluoroethylene) (PTFE)

The effect of electron beams on poly(tetrafluoroethylene) (PTFE) at elevated temperatures above the melting point on oxygen-free conditions has been studied using differential scanning calorimetry (DSC), wide-angle X-ray scattering (WAXS), Fourier-transform infrared (FTIR) spectroscopy, thermo-gravimetric analysis (TGA) and tensile test. The investigations have shown that the chemical structure and several properties of PTFE are greatly altered by the irradiation. DSC and WAXS indicate that the crystallinity of the PTFE irradiated with high doses is reduced. CF sub 3 side groups and branched structures are assumed to hinder the crystallization. TGA has shown that the thermal stability of the radiation-modified PTFE is considerably lower than that of unirradiated PTFE.