REDUCING THE FLAMMABILITY OF RECYCLED POLYETHYLENE

Abstract

The widespread use of recycled polyethylene in various industrial applications is significantly limited by its high flammability, which poses serious safety concerns in the construction, automotive, and electrical industries. This comprehensive review examines existing strategies and emerging technologies to reduce the flammability of recycled polyethylene by incorporating flame retardant systems. The study analyzes metal hydroxide-based approaches, swelling formulations, phosphorus-containing additives, and nanomaterial reinforcements, evaluating their mechanisms, effectiveness, and impact on mechanical properties. Metal hydroxides, such as aluminum hydroxide and magnesium hydroxide, work by endothermic decomposition, releasing water vapor that dilutes flammable gases and cools the fire zone. The swelling systems create protective carbon layers through synergistic interactions between acid sources, carbonization catalysts, and blowing agents. Future research directions include the development of biobased flame retardants, multifunctional additives that provide fire resistance and mechanical reinforcement, and improved compatibility strategies for recycled polymer matrices.