Physico-chemical characterization of the effect of excimer laser irradiation on PMMA thin films

We study the cross-linking process taking place in poly(methylmethacrylate) upon irradiation at 248 nm with an excimer laser. The physical and chemical properties of the irradiated polymer are traced with FTIR spectroscopy, UV–visible spectrophotometry, and differential scanning calorimetry. In particular, the evolution of the glass transition temperature is examined as a function of the total energy deposited on the polymer surface. It appears that there occurs a competition between a cross-linking reaction and a photodegradation reaction.