Influence of ultraviolet radiation on polymethylmethacrylate (PMMA)

Polymethylmethacrylate (PMMA) was irradiated (360–811 h) in a UV-B accelerated aging chamber at room temperature and oxidizing atmosphere. The macromolecular changes attributed to the radiation were investigated by means of tests such as: traction test, percent cross-linking, thermogravimetric analysis (TGA), Fourier transform spectroscopy (FTIR) and ultraviolet visible spectroscopy (UV–Vis). Scanning electron microscopy (SEM) analysis was used to evaluate the influence of radiation on PMMA fracture behavior. The results indicate that changes occurred due to UV-B radiation, such as chain scission and color change, which may lead to a decrease in resistance. The mechanical properties curves showed a similar pattern for the irradiated samples, which are confirmed by the fragile fracture surface identified.