An investigation into waterborne intumescent coating with different fillers for steel application

Abstract

Purpose This study aims to discuss the modification and/or improvement of intumescent coating system by incorporating waterborne resin with an appropriate combination of flame-retardant additives and four different fillers, namely, TiO2, Al(OH)3, Mg(OH)2 and CaCO3. Design/methodology/approach Coating mixtures are characterized using the Bunsen burner, thermogravimetric analysis, limiting oxygen index, scanning electron microscope, static immersion bath, Fourier transform infrared and adhesion tester. Findings Results show that the combination of coating with CaCO3 filler significantly improved fire protection performance because of its thick char layer and the equilibrium temperature being 264°C. Char layer showed a uniform dense foam structure on micrograph and this formulation had adhesion strength of 2.13 MPa, which indicates effectiveness of the interface adhesion on substrate. Conversely, the combination of coating with Al(OH)3 exhibited highest oxygen index of 35 per cent, which resulted in excellent flammability resistance. Research limitations/implications This paper discusses only the effect of mineral fillers on properties of intumescent coatings. Practical implications In the modern design of building infrastructure, fire safety is significant for the protection of human life and assets. The application of intumescent coating in buildings is currently practiced because of its effect on material flammability during a fire. Originality/value The analysis method to evaluate the performance of water-borne resin with different fillers is formulated, and it could be applied in all kinds of coatings and mixtures to be used as an effective fire protection system for steel constructions.