Effects of zirconium silicate reinforcement on expandable graphite based intumescent fire retardant coating

Abstract

The effects of zirconium silicate as a fire retardant reinforcement in the mixture of expandable graphite (EG), ammonium poly phosphate (APP), melamine, boric acid, bisphenol A epoxy resin BE-188(BPA) and ACR Hardener H-2310 polyamide amine are presented. Different formulations were developed to study the effects of zirconium silicate on char expansion, heat shielding, char morphology and composition after fire test. The coatings were tested at 950 °C using Bunsen burner for 1 h. The results show state that the zirconium silicate enhanced fire protection performance of intumescent coating. The morphology of the char was studied by Field emission scanning electron microscope (FESEM) after furnace fire test. X-ray Diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) results showed the presence of graphite, borophosphate; boron oxide and boric acid in the char. Thermogravimetric analysis (TGA) showed that zirconium silicate enhanced residual weight of char. X-ray photoelectron spectroscopy (XPS) analysis showed that 5% zirconium silicate enhanced the carbon content up to 60.87% and lowered oxygen content to 28.09% in the residual char which proved helpful in improving the fire resistance performance of coating. Pyrolysis analysis confirmed that IF5-ZS releases less gaseous products concentration compared to IF-control coating.