Effect of cenospheres on the char formation and fire protective performance of water-based intumescent coatings on structural steel

Intumescent coatings are passive fireproofing materials, used to prevent fire induced structural collapse of tall buildings by decreasing the heat transfer to the substrate. Present research describes the results of various formulations developed to study the effects of fly ash cenospheres on the heat shielding performance of intumescent passive fire proofing coatings during fire testing. The intumescent fire retardant coating formulations (IFR) were tested at nearly 950 degrees C for 1 h. The results showed that the coatings form a stable char having good adhesion to the substrates. The coating degradation was studied using Thermo gravimetric analysis (TGA). The morphology of chars was studied by Environmental scanning electron microscopy (ESEM). The coating char after fire test was examined by X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The presence of titanium phosphate and boron phosphate in the residual char was observed and XRD also confirmed the interaction of cenospheres with the coating ingredients at high temperatures. TGA showed that IFR CN 4 containing 10 phr of cenospheres enhanced residual weight by 39.30%. It is also concluded from the results that cenospheres increased the anti oxidation ability of the intumescent char. (C) 2015 Elsevier B.V. All rights reserved.