Analysis by Raman and infrared spectroscopy combined with theoretical studies on the identification of plasticizer in PVC films

Raman and Fourier Transform infrared spectroscopy were used to study the vibrational spectra in commercial polyvinyl chloride (PVC) flexible films. In order to have insights of the PVC and the plasticizer structures, density functional theory calculations were conducted via B3LYP hybrid functional. The infrared and Raman calculations took into account geometry optimization of the PVC film, the plasticizer DEHA and the convolution of both. The convoluted spectra were then compared with the experimental data. Finally, the thermal stability of the PVC films was checked through one-hour thermal treatment of the samples comprising temperatures ranges from 50 to 200 °C.