Effects of natural weathering on the degradation of alkaline-treated peanut shell filled recycled polypropylene composites

The present work evaluates the potential of the natural filler peanut shell powder (PSP) on the properties and degradation behavior of alkaline-treated PSP filled recycled polypropylene (RPP) composites. For this purpose, 0-40 wt% of untreated PSP and hydrogen peroxide-treated PSP were incorporated into RPP composites that were fabricated via a melt-mixing molding system. The fabricated composites were exposed to the natural environment of Penang, Malaysia for 6 months. The properties of both untreated and treated RPP/PSP composites were assessed. Results showed that the tensile properties of the treated RPP/PSP composites were higher than that of the untreated RPP/PSP composites. The treated RPP/PSP composites were less affected by weathering degradation compared to the untreated RPP/PSP composites. An increase in the carbonyl index of both composites also confirmed that some degradation had taken place. On comparing the crystallinity of both composites, the treated composites showed lower crystallinity than untreated composites. J. VINYL ADDIT. TECHNOL., 25:26-34, 2019. (c) 2018 Society of Plastics Engineers