Artificial aging of high-density polyethylene by ultraviolet irradiation

Artificial aging of high-density polyethylene exposed to UV irradiation, with wavelength close to 350 nm, in the presence of air, has been studied in this paper. Such irradiation is one of the environmental factors which affect most to weather exposed polyethylene. The structural modifications and chemical changes experienced by the polymer by the application of Fourier-transform infrared spectrophotometry (FTIR), mainly polymeric chain breaking, branching and oxidation, have been studied. The variation of crystallinity has also been determined by FTIR. Finally, the evolution of the mechanical properties versus the irradiation time has been closely followed.