Effects of hybrid flame-retardant fillers on fire-resistive and mechanical properties of solvent-borne intumescent coatings

The aim of this research project was to investigate the effects of hybrid flame-retardant fillers on the fire protection and mechanical properties of solvent-borne intumescent coatings. Formulations of intumescent coatings with different combinations of flame-retardant fillers were developed and investigated through Bunsen burner test, adhesion strength test and Scanning Electron Microscopy (SEM). It was found that the formulation of intumescent coating was optimized with four combinations of flame-retardant fillers in proper compositions and had improved the fire protection performance and mechanical properties of the coating. In overall, filler compositions of coating sample D (1 wt.% nano CES/ 2 wt.% expandable graphite/ 1 wt.% zinc borate/ 4 wt.% calcium silicate) had contributed to positive fire protection performance (equilibrium temperature of 190 °C) and adhesion strength (2.62 MPa). Significantly, the incorporation of an appropriate combination of hybrid nano CES bio-filler, expandable graphite, zinc borate and calcium silicate had led to a better fire protection performance and mechanical properties of the solvent-borne intumescent coating.