Photodegradation of colored polyethylene films

Abstract The changes of mechanical, physical, and chemical properties of colored low‐density polyethylene films under ultraviolet light were investigated. The study was performed using commercially manufactured colored pigments: Cadmium Yellow, CdS/ZnS; Ultramarine Blue, Na 7 Al 6 ‐Si 6 O 24 S 3 ; Copper Phtalocyanine Green, C 32 H 2 N 8 Cl 14 Cu, and Chrome Orange, PbCrO 4 .PbO. Two series of colored film samples were subjected to artificial aging in a weatherometer. The first series contained no ultraviolet absorber and the second one contained substituted 2(2′‐hydroxyphenyl)‐benzotriazole (Tinuvin 328). It was found that the extent of film deterioration depends on the nature of the pigment utilized. Two types of pigment influence on the rate of film properties changes were observed. When using Cadmium Yellow an enhanced process of polyethylene degradation was noted, while, in contrast to this a delay in aging of films was observed with Chrome Orange, Copper Phtalocyanine, and Ultramarine Blue.