Polyvinyl chloride (PVC), is one of the main synthetic materials used widely in many applications of our life aspects today. Though, the practical usage of it was always affected by some destructive factors like UV-light and heat. The optical and surface characteristics of pure and modified PVC thin films were compared throughout a temperature range of 25–55 °C. It was found that the intensity of the amine group in modified PVC varied with temperature. Surface morphology properties studied by AFM results; the ionic liquid was proven to comparably increases the stability of PVC surface while the roughness was less than pure PVC with increasing temperature. Optical microscope pictures, manifest PVC as drops at 55 °C, while, in modified PVC at the same temperature, the PVC surface was noticeably more stable. Finally, the energy gap of PVC pure and modified PVC thin films are studied. At 55 °C, the modified PVC's energy gap value increased from 3.64 eV at ambient temperature to 4.28 eV. This makes it more isolated when compared to pure PVC, which has an energy gap of 3.04 eV at ambient temperature and 3.1 eV at 55 °C and is a semiconductor.