Benign design of intumescent flame retardant coating incorporated various carbon sources

The influence of various carbon sources on flame retardancy of polyester resin-based intumescent flame retardant (IFR) coating is investigated to clarify the different effects during combustion, which contain expandable graphite (EG), carbon black (CB), vermicular graphite (VG), and natural flaky graphite (FG), respectively. The results of cone calorimeter (CC) determine that the CB doped coating exerts the highest flame retardancy, evidenced by the lowest fire growth index (FGI) of 0.041 kWm(-2).s(-1) and the highest fire performance index (FPI) of 14.623 s.m(2).kW(-1), due to the barrier effect of continuous and compact char residues. However, the VG accelerates the fire propagation owing to candlewick effect, although the heat release rate shrinks compared with that of barely IFR coating. It demonstrates that CB is beneficial for benign design of carbon-containing IFR coating. (C) 2019 Elsevier Ltd. All rights reserved.