Preparation and characterization of pure and copper-doped PVC films

Pure and Cu2+-doped polyvinyl chloride (PVC) polymer films were prepared using the solution cast technique. Investigations were conducted using DSC, TGA, XRD, FT-IR, UV-Vis, SEM and EPR. Differential scanning calorimetry studies suggested that the Cu2+ samples have higher values of the glass transition (T-g) temperature, and thermo gravimetric studies show that weight loss of polymer film indicates the improved thermal stability of the polymer film. The features of the complexation of the poly-mer films were studied by X-ray diffraction. FT-IR spectra exhibits the bands in three regions, which are attributed to C-Cl, C-C and numerous CH groups of stretching and bending vibrations. The absorption spectra have been recorded in the wavelength range 200-900 nm. The absorption edge, direct bandgap, indirect bandgap and urbach energy have been evaluated. Film morphology was examined by scanning electron microscopy. XRD, DSC and SEM reveal the amorphous nature and surface morphology of polymer films, respectively. Electron paramagnetic resonance studies were used to calculate the number of spins and paramagnetic susceptibility as a function of dopant concentration, all the Cu2+-doped PVC samples exhibit signal with g values g(perpendicular to) = 2.176 and g(parallel to) = 2.254. The observed variation in the EPR signal intensity is due to variation in the dopant concentration.