The effect on Expansion and Thermal degradation of 63um Expandable Graphite on Intumescent fire retardant coating composition

This project has been designed to the preparation of halogen free intumescent fire retardant (IFR) coating. Flake graphite (particle size 63µm) was reacted with different acids to prepare the expandable graphite which was further used as a carbon source in IFR coating. The IFR coating was based on expandable graphite (EG), ammonium poly phosphate (APP) as a acid source, melamine as a blowing agent, boric acid as additive and bisphenol A epoxy resin BE-188 (BPA) was used as a binder with ACR Hardener H-2310 polyamide amine. The IRF coating was coated on the structural steel substrate and cured at ambient temperature. A range of different formulations were developed to study the expansion, morphology of char and thermal properties of the IFR coating. The IFR coating was tested at 500oC for two hours in the furnace and coating was stable with excellent adhesion by the formation of char which completely insulate the steel substrate from fire. The formation of the final charring layer and their morphological structures was studied by SEM, XRD and FTIR techniques. Thermo gravimetric analysis (TGA) was used to study the thermal stability of coating. Results showed that such a coating has excellent physical, chemical properties and EG is a carbon source that will create uniform protective layer on the surface of the insulating materials.