Thermal Behavior and Barrier Mechanism of Intumescent Fire‐Retardant Epoxy‐Based Coating

ABSTRACT This study quantifies the thermal stability of fire‐retardant epoxy‐based coatings containing halloysite nanotubes (Hals) and melamine‐formaldehyde (MF) resin by applying an isoconversional kinetic method on thermogravimetric analysis (TGA) data. Heating rates of 5–20°C/min were applied to evaluate activation energy and thermal behavior. The intumescent mechanism was observed between 285°C and 300°C using differential scanning calorimetry (DSC). Differential thermal analysis (DTA) revealed a 40% and 57% reduction in heat flow when 1 and 2 wt% were added to the epoxy coating containing intumescent and MF, indicating a strong synergistic effect between the barrier and intumescent mechanisms. Notably, the simultaneous addition of Hals and MF increased the activation energy of the coatings from 237 to 907 kJ mol −1 . Engineers can utilize the findings from this study to select optimal fire‐retardant epoxy coatings, optimize formulations for enhanced thermal stability, and predict the thermal behavior of coatings for effective fire safety design in structural applications.