Life Cycle Assessment of Calcium-Rich Industrial Waste Reinforced Polypropylene and Low-Density Polyethylene Composites Using the Cradle-to-Gate Approach

The first life cycle assessment (LCA) of injection-molded composites made of low-density polyethylene (LDPE) and polypropylene (PP) reinforced with calcium-rich flue gas desulfurization (FGD) gypsum and marble waste is shown in this work. The life cycle phases of the manufacturing of polymer composites were assessed using the methodological framework of IS/ISO 14044:2006. Midpoint indicators were evaluated by the ReCiPe method. To determine the composition, the physicochemical properties of the used FGD gypsum and marble waste were analyzed to ensure utilization in subsequent composite materials. American Society for Testing and Materials (ASTM) standards were followed for mechanical testing to check the quality of the developed composites. The flexural strength of the developed polymer composites was higher than that of pristine specimens with a 20–80 wt % filler concentration. Using the openLCA software and ecoinvent database, a cradle-to-gate LCA was performed for the developed composites. The global warming potential of the MW-PP composites is 1.01–1.06 times less than those of the other developed reinforced composites. The results of the present research are useful for creating environmentally friendly technologies, particularly the injection-molding practice.