Phosphoramidates as promising low-loading flame retardants for low density polyethylene

The search for non-halogenated, environmentally friendly flame retardants for plastics remains a major priority for industry. Current solutions rely mainly on the use of inorganic salts in high loading, which also alters the material properties. In this regard, phosphoramidate compounds have shown promising results at already low loadings in different polymeric materials; however, they still remain a relatively unexplored option. Here, we study the potential use of several phosphorus-based flame retardants (P-FR) for low density polyethylene (LDPE). Characterization of the prepared LDPE P-FR formulations showed minor differences between their physicochemical properties and those of the virgin LDPE polymer, while exhibiting a notable flame retardancy effect. Remarkably, the synthesized P-FR outperformed the commercially used inorganic salts when used at the same loadings. Finally, two potential methods for the valorization of waste LDPE were investigated to evaluate the effect of the P-FR on the chemical recyclability of the polymer.