Effect of mixing temperature in the development of green polypropylene – coal bottom ash composite slab

Abstract

Coal bottom ash (CBA) is a residue produced from the burning of pulverized coal for electricity generation. The high porosity and low abrasion resistance of CBA hindered its commercialization; thus tonnes of CBA were discharged in landfills and surface impoundments. Considering the adverse social and environmental issues associated with disposal management, it is imperative to optimize the utilization of CBA. About 30% of CBA were homogeneously blended with Polypropylene (PP) to produce a “green” PP-CBA composite slab. The influences of mixing temperatures on the physical, chemical and mechanical properties of the fabricated slabs were examined in the study. FESEM micrographs illustrated a smoother surface with a low density of voids in composite systems mixed at low temperatures (190°C). Moisture content was retained in the PP-CBA matrix and imparted supplementary strength to the composite. The relatively amorphous state of the composite allowed for easier dispersion of molecules under applied stress. From the tests, PP-CBA composite slabs mixed at 190°C exhibited the largest drop impact energy and ideal physical and structural properties.