Effects of Blend Composition on the UV Stability of Polyethylene Blends

Abstract

The main goal of this study was to investigate the effects of blending composition on the UV stability of different polyethylenes (PEs). This would help in having a good understanding of modifying these materials in different ways, to make them suitable for different target applications. The susceptibility of different blends of low density polyethylene (LDPE) and high density polyethylene (HDPE) to UV degradation were investigated. LDPE/HDPE blends with varying ratios (80/20, 60/40, 40/60, and 20/80), were prepared by melt-mixing technique using mini-twin-extruder. The LDPE, HDPE and their blends were conducted and exposed to UV-B light (340nm) for 415h in accelerated weathering test machine. To follow the degradation and to characterize the surface changes of LDPE, HDPE and their blends, fourier transform infrared spectroscopy (FTIR), contact angle measurements and optical microscope were utilized. It was observed that the susceptibility of LDPE/HDPE blends to degradation varied according to blending composition. Blends-rich with HDPE possess better resistance to UV degradation than virgin LDPE and blends-rich with LDPE. Moreover, blend with the composition of LDPE (20)/HDPE (80) was less susceptible to UV degradation than other blends. In line with previous study, blending composition could be used as indicator to predicate the final properties and suitable application of the final LDPE/HDPE blend.