Investigation on the properties of gamma irradiated of polytetrafluoroethylene fibers.

The physical, thermal, and chemical properties of gamma-irradiated polytetrafluoroethylene (PTFE) fibers were investigated using X-ray diffraction (XRD), differential scanning calorimetry (DSC), and Fourier transform infrared (FTIR) spectroscopy. Scanning electron microscopy (SEM) was also used to analyze the surface morphology of irradiated fiber samples. PTFE fiber samples were irradiated by gamma radiation doses ranging from 3 kGy to 40 kGy. The XRD analyses and DSC measurements showed the improvement of crystallinity by gamma irradiation with dose up to 25 kGy reflecting the induced crosslinking with irradiation for PTFE fibers. The crystallinity was found to decrease with higher dose of 40 kGy, reflecting induced amorphization of the polymer sample at the high radiation dose. The calculated crystallite size and XRD parameters showed obvious variations with sample irradiation. The FTIR results showed the liberation of CF2 groups and the formation of some new chemical bonding with crosslinking-induced irradiation. The SEM micrographs revealed no variation in the surface morphology of the irradiated fiber samples than the pristine fiber.