Polypropylene/postconsumer recycled poly(ethylene terephthalate) hybrid composites: evaluation of morphological, mechanical, thermal and electrical properties

Abstract

Polypropylene (PP)/postconsumer recycled poly(ethylene terephthalate) (rPET) blend has gained much attention as an environmentally friendly and economical material in various industrial applications. The aim of this study is to improve the properties of PP/rPET blend with talc, glass fiber, and carbon fiber mixture to be included by twin-screw extrusion followed by injection molding. Maleic anhydride grafted polypropylene (PP-g-MA) and chain extender (Joncryl ADR 4368) were used as the coupling agent. The effects of various coupling agents were evaluated in terms of the mechanical, morphological, electrical, and thermal properties of the PP/rPET hybrid composites. The mechanical properties of the composites were characterized by tensile and Charpy impact tests. Scanning electron microscopy (SEM) was used to assess the fracture surface morphology and the dispersion of the filler. The thermal properties of the composites were characterized using differential scanning calorimeter (DSC), heat deflection temperature (HDT), and Vicat softening temperature (VST) tests. The results showed that the composites morphology was dramatically affected by the addition of coupling agent. Tensile and impact strength increased in the presence of coupling agent of the composite due to the improved interaction at the interface of polymers. HDT and VST of the composite were increased significantly in the presence of PP-g-MA.