OPTICAL an‎d ELECTRICAL PROPERTIES OF POLYVINYL-CHLORIDE (PVC) FILMS

The optical properties of the polyvinyl-chloride thin films were studied which include their absorbance, transmittance, reflectance spectra, band gap, and refractive index, before and after annealing at T = 75οC for 24hours . The films were found to exhibit high transmittance, low absorbance and low reflectance in the visible, and near infrared region up to 1100nm. However, the absorbance of the films was found to be high in the ultra violet region with peak around 306nm. The dielectric constant ε′, dielectric loss ε″, and ac conductivity of polyvinyl-chloride were obtained at different frequencies and temperatures. The experimental results show that ε′ and ε″ decreased with increasing frequency, which indicates that the major contribution to the polarization comes from orientation polarization. The value of ε′ increased with increasing temperature, which is due to great freedom of movement of the dipole molecular chains at high temperature.