Thermoanalytical studies of intumescent systems

Abstract Fire retardant intumescent coatings which produce a swollen char on heating are being frequently used to protect buildings containing structural steel from the effects of exposure to high temperatures caused by fire. This paper contains details of a study carried out using thermal analysis techniques to elucidate the mechanisms of the development of intumescent chars during the heating of an intumescent coating system based on ammonium polyphosphate, pentaerythritol and melamine. In particular, the role of melamine as the spumific agent has been studied. The melamine is shown to react chemically with the ammonium polyphosphate in addition to carrying out its role as the spumific, or blowing agent.