Phosphorus-Containing Flame Retardants

Organic polymeric materials when subjected to heat for a sufficiently long time can undergo thermal- and/or thermo-oxidative decomposition, resulting in volatile components. These volatiles, when mixed with the ambient air, can form combustible mixtures and in the presence of an external pilot can undergo flaming combustion, often resulting in toxic products. Some polymers, depending on the chemical composition, can also produce varying amounts of relatively noncombustible char residues. In any case, given that all combustion reactions are exothermic in nature, they can lead to thermal feedback from the fire plume to the surface of an unburnt polymer, thus resulting in a sustained combustion cycle. Therefore, fire retardation of polymeric materials is still an active area of research, where the use of phosphorus-containing compounds has proven to be beneficial as compared to other elements and/or their compounds. The present chapter provides some recent advances in this area.