Recycling and surface modification of waste bottom ash from coal power plants for the preparation of polypropylene and polyethylene composites

The production of waste bottom ash (BA) from coal power plants in the west coast of South Korea has been a serious environmental problem to resolve. In this investigation, waste BA was recycled to prepare BA/polypropylene and BA/polyethylene composites, and their mechanical properties were compared. The hazardous metal content in the waste BA was minimal, and the waste BA was not contaminated by sea water. The surface of the BA was coated with one of three cationic surfactants, cetylpyridinium chloride, benzethonium chloride, or benzalkonium chloride, to improve the interface compatibility between the polymer matrices and BA surface. The mechanical properties of the BA composites decreased as the BA content increased and were dependent on the content of BA rather than on particle size. Coating surfactants onto BA significantly improved the mechanical properties, especially the compressive strength, of the BA composites. Finally, the BA composites were successfully applied in the fabrication of a car parking safety product that satisfied the required safety standards.