The effect of artificial weathering and hardening on mechanical properties of HDPE with and without UV stabilizers

Abstract

Outdoor applications of polymers are increasing rapidly. So, the ability of polymers to withstand environmental degradation became very important for many researchers. The effect of artificial weathering and hardening on the stability of high-density polyethylene (HDPE) with and without stabilizers has been studied. HDPE samples were prepared with UV absorbers (UVA) and hindered amine light stabilizers (HALS) at different concentrations. The results indicated that non-stabilized HDPE was mechanically dead after 300 h of exposure, where it lost almost 98% of its toughness, and the percentage of elongation at break reduced from 1223% to 21%. It was clear that stabilizers sustain the mechanical properties of samples efficiently until 900 h. However, the best performance was observed by samples containing a specific concentration of HALS and UV absorber, which retain most of its properties until 1300 h. The hardening test was performed by heating the samples to 125 °C then suddenly cooled at 0 °C, 25 °C, and 50 °C. The mechanical properties of HDPE were significantly affected by hardening.