Microstrain analysis of proton irradiated PET microfiber

The microstrain developed due to the molecular deformation of polymeric material because of MeV proton irradiation causes shifting of peak position of both X-ray diffraction lines and Raman bands in polyethylene terephthalate (PET) microfiber. This was investigated using X-ray diffractometer and micro-Raman spectrometer. In the present work, the PET microfiber of 1.5 dpf was irradiated with 3 MeV proton at small fluences 1 × 1010 p/cm2 to 1 × 1012 p/cm2. The radiation induced microstrain developed in PET microcrystallites and its size effect was investigated applying XRD. The shift of 0.5 cm−1 in the Raman peak position of 1616 cm−1 to a lower value due to proton irradiation at small fluences confirmed the development of microstrain.