The importance of intumescent systems for fire protection of plastic materials

A review of recent developments in the applications and actions of intumescent fire‐retardance is given. An attempt has been made to classify the main systems of importance such as melamine, ammonium polyphosphate, melamine phosphate, pentaerythritol phosphate, sodium silicate, vermiculite, expandable graphite and microbeads. They are defined in terms of the Berthelot number which is the product of heat of vaporization or decomposition and volume of gases evolved. In principle, only two kinds of gases are produced from this group, namely water vapour and ammonia (from melamine). The heats of decomposition are readily calculated from heats of formation. An important aspect which is not included in the Berthelot number is the ignition residue in the shape of glassy foam or a cellular enamel. © 2000 Society of Chemical Industry