Study of heat and UV radiation exposures on HDPE geomembranes

This study analyzed the behavior of three HDPE smooth geomembrane samples of 1.0, 1.5, and 2.0 mm thicknesses under heat exposure for 8760 h and the combined effect of UV radiation for 8760 h followed by heat aging for 4380 h. The results show high antioxidant consumption, an increase in viscosity, and stress cracking susceptibility, demonstrating the occurrence of cross-linking and accelerating oxidative degradation. Samples under the combined effect of UV radiation followed by heat exposure showed advanced oxidative degradation in comparison to those under heat exposure. DMA results corroborate the morphological changes in the polymer, exhibiting different thermal behavior for some types of exposure and different samples’ thicknesses.