Fabrication of Fluorine and Nitrogen-Based Flame Retardants Containing Rigid Polyurethane Foam with Improved Hydrophobicity and Flame Retardancy

In this work, a novel flame retardant containing fluorine and nitrogen was synthesized by using a copper-catalyzed azide-alkyne cycloaddition reaction, resulting in a hydroxyl-terminated compound with a triazole structure. This flame retardant was added to rigid polyurethane foam (RPUF) formulations in varying percentages (5, 10, and 15%) in order to chemically bond to isocyanates in the foam. Modified RPUF samples were analyzed for structural properties (FTIR), flammability (cone calorimetry, LOI, TGA), thermal conductivity, morphology (SEM), mechanical properties, and hydrophobicity. The results indicated significant improvements in flame retardancy with higher LOI values and lower peak heat release rates. The flame retardant chemically bonded to the foam, maintaining its mechanical integrity and thermal insulation and increasing hydrophobicity due to its fluorine content. This study highlights the potential of fluorine- and nitrogen-containing flame retardants for future fire-resistant materials.