Changing the optical properties of poly(methyl methacrylate) superficial films during UV irradiation

Abstract

In this work, the simple spectroscopic method is presented to study the change of the optical constants n and k of the poly(methyl methacrylate), UV-irradiated. The infrared reflection-absorption spectra were recorded at a single incidence angle. The reflection-absorption spectra of the poly(methyl methacrylate) thin films were processed using classical dispersion analysis and a fitting program to obtain optical constants n and k. The shift, the variation of intensity, or broadening of the absorption bands during the UV degradation, were watched in the extinction coefficient k spectrum. The changes in the extinction spectrum of UV-irradiated polymer films are consistent with the photodegradation mechanisms described in the literature.