Structural modification of poly(tetrafluoroethylene) by electron beam radiation in air

Abstract

In this research, structural modification of poly(tetrafluoroethylene) radiated by electron beam at room temperature in air has been studied. Degree of crystallinity was measured using density measurement, differential scanning calorimetry, and X-ray diffraction. Mechanical properties of radiated poly(tetrafluoroethylene) including tensile strength and % strain to failure were also tested and reported. The results of this research provide a better understanding of the morphology and thermal behavior of radiated poly(tetrafluoroethylene). Density measurement shows that the crystallinity of radiated poly(tetrafluoroethylene) increases with increasing radiation dose, up to 100 kGy. The number-average molecular weights were estimated from the heat of crystallization measured by differential scanning calorimetry technique. Results from X-ray diffraction patterns of radiated poly(tetrafluoroethylene) samples give only one well-defined crystalline peak at a scattering angle of 2 θ = 17.5–18.6°. Mechanical testing of radiated poly(tetrafluoroethylene) reveals that dose at which half value of the elongation at break appears is about 10 kGy, while the dose at which half value of the tensile strength appears is about 7 kGy. Results from this research can be used in recycling of poly(tetrafluoroethylene) as well as extending its application in polymer industries as a fluoroadditive or micropowder.