Effect of Mixing on the Optical Parameters of Polymer Blend (PMMA:PVC:PS) Thin Films

Abstract

The thin films have been prepared using casting method at normal weather conditions of pressure and temperature. The films treated thermally for three hours at 45 °C. The UV-VIS double beam technique used to determine absorption and reflection spectrum. The thickness of the prepared thin films is measured using a handheld gauge of coating thickness measurement. Excel and MATLAB program used to calculate and simulate parameters and figures. The optical properties of PMMA:PVC:PS mixtures have been investigated. There is a clear change in the optical parameters due to mixing ratio. The result shows the indirect energy gap values reduced from 1.58 to 1.9 electron-volts. Mix a ratio of PMMA, PVC & PS leads to enhance some of the optical parameters like optical energy gap, absorbance, extinction coefficient and optical conductivity. The four kinds of thin films have different properties: The polymer blend (50%PMMA:25%PVC:25%PS) has the smallest values of the energy gap and linear refractive index, and the highest extinction coefficient values. The polymer blend (25%PMMA:25%PVC:50%PS) has a small value of energy gap and the best optical conductivity. The polymer blend (25%PMMA:50%PVC:25%PS) has the highest Urbach energy and absorption for the short wavelength (370 to 620 nm). The polymer blend (50%PVC:50%PS) has a good reflection, linear refractive index and skin depth, but it has the lowest values of extinction coefficient and optical conductivity.