Flame retardants: halogen-free systems (including phosphorus additives)
There are three essential conditions to be met if a polymer, once ignited, is to continue burning. There must be a supply of heat to the bulk polymer, a generation of fuel (typically volatile decomposition products) and there must be a flame. Halogen-based systems act by a well-documented flame poisoning mechanism in the vapour phase. The alternative halogen-free systems, which encompass a wide variety of additives, tend to act by mechanisms which disrupt heat flow and the supply of fuel to the flame. Here the mechanisms are not always understood in great detail but two broad types of flame retardant action can be defined.
Keywordsendothermic decomposition alumina trihydrate magnesium hydroxide phosphorus organophosphorus intumescent flame retardants melamine
Unable to display preview. Download preview PDF.