The effect of carbon black, ultraviolet (UV) stabilizer and color pigment on the mechanical property of polyethylene (PE) has been investigated. The transition of fracture mode from ductile to brittle upon UV exposure is identified through microscopic examination of fracture surface. This transition is responsible for the degradation of mechanical properties.
The carbon black doped PE shows excellent UV resistance regardless of the presence of UV stabilizer. The mechanical properties of the PE remained unchanged even after 50-days UV exposure. The ductile fracture mode is also maintained in this case. The addition of red color pigment exhibited a very poor UV resistance.