Effect of γ-irradiation on thermal and thermoluminescence properties of polystyrene/europium (III) oxide composite film.

In the present study, polystyrene:europium (III) oxide polymer films at a ratio of 95:5 wt% were prepared using a solution casting technique. These polymeric films were irradiated with 5, 25 and 50 kGy γ-radiation doses and their thermoluminescence (TL) and thermal properties were studied as a function of radiation dose. Analysis of Fourier transform infrared spectra revealed different modes of vibration and polymer-filler interaction. Reduction of vibrational modes with radiation dose was observed. The TL glow curve intensity was observed to increase with increasing radiation dose and to become broader in the 378 K and 444 K regions. Detrapping of electrons implied by the glow curve was caused by thermally induced macromolecular motion, concurrent with β-relaxation in polystyrene. The TL glow curve parameters were computed using a glow curve deconvolution method. Differential scanning calorimetry analysis indicated that the glass transition temperature (T ) increased with increase in dose, suggesting crosslinking of the polymer chain. Scanning electron microscopy analysis evidenced the change in surface morphology due to γ-irradiation.