Application of a Phosphazene Derivative as a Flame Retardant for Cotton Fabric using Conventional Method and Supercritical CO2

Conventional pad-dry-cure (non-scCO2) and supercritical carbon dioxide (scCO2) application methods were used to study the effectiveness of a newly synthesized phosphazene derivative as a flame retardant on cotton fabric. The 1,1′,4,5-tetrahydrotrispiro[1,3,2-diazaphosphole-2,2′-[1,3,5,2,4,6]triazatriphosphinine-4′,6”-dibenzo[d, f][1,3,2] dioxaphosphepine-6′,6”′-dibenzo[d, f][1,3,2]dioxaphosphepine] (2), was synthesized in two steps, in high overall yield, and applied onto cotton fabrics. The flame retardant properties of the treated fabrics were examined by 45° angle flammability test, limiting oxygen index test (LOI), microscale combustion calorimetry (MCC), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The results indicate that fabrics treated with 2 are flame resistant; however, non-scCO2 fabrics performed better than scCO2 fabrics in a preliminary durability study.