This study aimed to investigate the effect of organoclay concentration variation (1-5 wt%) on the weathering resistance of epoxy resin in terms of the strength, modulus and weight changes of the specimens after exposure to accelerated weathering conditions. Transmission electron microscopy (TEM) revealed an exfoliated and good dispersed nanofiller structure throughout the matrix up to 3 wt% loading. The tensile strength, modulus, and weight of the samples decreased after combined UV radiation and condensation, with much less extent for the nanocomposites than neat epoxy indicating that the presence of organoclay led to dominant enhancement in mechanical properties endurance of epoxy resin to environmental degradation. Nanocomposites also displayed much lower weight loss as compared to the unfilled epoxy after being subjected to the accelerated weathering by either temperature-humidity or by combined UV radiation and condensation.
