Fire-resistive performance of intumescent flame-retardant coatings for steel

The purpose of this work is to study the efficiency and effect of different intumescent flame-retardant formulations on the performance of steel in the event of a fire. The formulations are based on flame-retardant additives into which silica fume (SF) as a binder and chicken eggshell (CES) as a flame-retardant filler have been incorporated to synthesize water-based intumescent coatings. The influence of binder and filler on the properties and fire-resistive performance of the coatings were investigated by using thermogravimetric analysis (TGA), scanning electron microscopy (SEM), small scale Bunsen burner test and furnace test. TGA results showed that by adding SF alone or in combination with CES, the residual weight and thermal stability of the coatings were increased, while showing improved surface structure in the SEM images. The combination of SF, CES and flame retardant additives showed the best fire protection performance with the highest thermal stability, greatest expansion and densest surface structure while having sufficient adhesion to remain in place during fire exposure.