Material behaviourInvestigating the effect of accelerated weathering on the mechanical and physical properties of high content plastic solid waste (PSW) blends with virgin linear low density polyethylene (LLDPE)

In developing countries, plastic solid waste (PSW) poses a serious threat due to the increase in the dependency on landfilling as well as other environmental issues. Hence, valorising the accumulated waste is essential to promoting more environmentally friendly practices. In this work, the mechanical and physical properties of virgin linear low density (LLDPE) and LLDPE blends with PSW are reported. The formulations studied contained the following virgin to waste ratios (wt.%/wt.%): 100/0, 75/25, 50/50, 25/75 and 10/90. The effect of photo-degradation on the studied specimens was investigated using accelerated weathering tests in a UV chamber. Young's modulus showed an increase with exposure duration due to change in the samples' crystallinity. The loss of mechanical integrity (i.e. stress and strain at rupture) of the samples studied was related to the photo-degradation mechanisms, namely cross-linking and photo-oxidation. Haze and light transmission measured indicated that there was a loss of the amorphous regions in the samples studied after about 200 h of continuous exposure. The total change in colour (ΔE) was estimated but did not show a clear trend, indicating a clear dependency on wash mechanism and continuous loss of polymer colour and degradation.