Mechanistic Aspects of Flame Retardation by Phosphorus-Containing Groups in Some Chain Growth Polymers

Elemental phosphorus and its various compounds have been widely used to flame retard a variety of polymers for several decades. They can be used either as reactives or as components in additive systems, and are believed to be active in the condensed phase, in the vapor phase and, perhaps to a lesser degree, at the interface. Generally, phosphorus-based flame retardants tend to decrease the ignition propensities of polymeric materials. However, the actual mechanistic pathway(s) in achieving this, believed to be suppressing the combustion efficiency, greatly depends on the structural features of the polymeric substrate as well as on the chemical environment of the phosphorus-containing compound(s) in question. In the present chapter, the mechanistic aspects of flame retardation by reactive phosphorus compounds in some commercially important chain growth polymers are discussed.