Characterization of the performance of an intumescent fire protective coating

The aim of this work is to study the efficiency of different intumescent formulations designed to protect steel in the case of hydrocarbon fire. The coating is based on a thermoset epoxy–amine resin system into which fire retardant agents, boric acid and ammonium polyphosphate derivative have been incorporated. The first part of the study evaluates, using large scale industrial furnace tests, the behavior of the thermoset resin containing alone or in combination with additives. It is revealed that in this epoxy resin, the combination between ammonium polyphosphate and boric acid leads to the best protective results. The second part of the study attempts to investigate more precisely the effect and the mode of action of the additives in terms of thermal stability, mechanical resistance and rheological properties using small scale lab tests, to explain why this combination works better than using the two fire retardants used separately. The experiments show that this combination leads to the smallest decrease of viscosity when the resin degrades, the highest mechanical resistance and the highest expansion.