The degradation of thin poly(methyl methacrylate) films subjected to different destructive treatments

A comparative study of the degradation of poly(methyl methacrylate) (PMMA) films deposited on metal mirrors as a result of heat treatment or irradiation with various UV or γ radiation is presented. The main degradation processes of PMMA during degradation are the random homolytic breakdown of carbon–carbon bonds in the polymer main chain and the photolysis of the lateral methyl groups and lateral esters to form free radicals. All observations on the reflection–absorption spectra are in agreement with the mechanism of PMMA film degradation, subjected to various types of destructive degradation: thermal heating, UV irradiation, or γ irradiation. Unlike other approaches, this one used the reflection–absorption spectra of PMMA thin films deposited on metal mirrors.