Research progress in the application of bulk solid waste in the field of flame retardation

The contemporary world faces critical resource and environmental challenges, resulting in a substantial surge in solid waste generation. This has intensified the urgency of effectively managing and recycling solid waste. In 2021, the production of bulk solid waste in China exceeded its peak in 2014. Due to environmental policies, this value reached its lowest point in 2018 and has shown a steady upward trend since 2019. A promising strategy involves incorporating solid waste into polymer flame retardants, not only facilitating resource reuse but also enhancing fire safety. This comprehensive review categorizes solid waste into industrial, agricultural, and synthetic types. The exploration systematically investigates how diverse forms of solid waste can be utilized for polymer flame retardancy. Industrial waste, including metallurgical residues, industrial metal byproducts, and soil derivatives, possessing attributes like metal ions, high thermal resistance, and modifiability, align well with flame retardant requirements, promoting resource efficiency. Agricultural and forestry residues, exemplified by lignocellulosic materials, feature surface-active groups suitable for flame retardant modification, bolstering polymer flame retardant capabilities. The study also extends to modifying synthetic solid waste, primarily recycled polymers. The review encompasses challenges in polymer flame retardancy with regard to different solid waste categories. Building on these insights, the review concludes by envisioning the potential of flame-retardant polymers in solid waste management.