Phosphogypsum Waste Used as Reinforcing Fillers in Polypropylene Based Composites: Structural, Mechanical and Thermal Properties

The industrial production of wet phosphoric acid in Morocco led to controversial stockpiling of waste phosphogypsum by-products resulting in the release of significant amounts of toxic impurities in salt marshes. In the framework of fighting against global climate change and efforts to reduce toxic industrial wastes (phosphate industry), this work presents a new polymer composite based on phosphogypsum (PhG) and polypropylene (PP).The compounds were produced by twin-screw extrusion and injection molding. The morphological results show that good affinity between PhG and PP led to good particle dispersion/distribution in the polymer matrix. Thermal characterizations showed that PhG particles improved the thermal stability of PP with a 50 °C increase at 40 wt%. The optimum tensile modulus was also obtained at 40 wt% with a 74 % increase over neat PP. Dynamical mechanical analysis showed that PhG addition can improve the viscoelastic properties of PP for potential applications under dynamic stress. Overall, it can be concluded that PhG is potential reinforcing filler for the production of PP composites and represents a promising avenue for the valorization of this waste as a new raw material while resolving some environmental issues.