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Novel Thermoset Nanocomposite Intumescent Coating Based on Hydroxyapatite Nanoplates for Fireproofing of Steel Structures

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Thermoset nanocomposite intumescent coating swells under the influence of heat forming a thick cohesive insulating barrier; it is one of the most effective ways for fire protection of steel structures. This study reports on the sustainable fabrication of hydroxyapatite (HA) nanoplates as an efficient phosphorous-based flame retardant agent (phosphorous content of 18.5 wt%). Epoxy nanocomposite, based on the synergism between HA particles and advanced intumescent flame retardant agent (commercially known as AP750) was developed. This novel nanocomposite was able to resist a direct flame source at 1700 °C and to self extinguish; it demonstrated an enhanced flammability performance in cone calorimetry with 51% decrease in the peak heat released. Nanocomposite layer of 3 mm thickness was employed for steel substrate protection against direct heat source. The developed intumescent coating was able to protect the steel substrate from heat source at 900 °C. It offered an improved performance, in terms of the coating’s mechanical barrier, and flame resistance properties. HA nanoplates could propose a gas phase effect due to the release of active flame scavengers such as \( {\text{PO}}_{2}^{ \cdot } \), PO·, and HPO·. Furthermore, HA could expose a condensed phase effect via the formation of a protective charr layer.

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This experimental work has been conducted at School of Chemical engineering, University of Nottingham, Nottingham, UK, and funded by Military Technical College, Cairo, Egypt.

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Correspondence to Sherif Elbasuney.

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Elbasuney, S., Maraden, A. Novel Thermoset Nanocomposite Intumescent Coating Based on Hydroxyapatite Nanoplates for Fireproofing of Steel Structures. J Inorg Organomet Polym 30, 820–830 (2020). https://doi.org/10.1007/s10904-019-01260-7

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  • Nanoparticles
  • Flame retardant
  • Nanocomposites
  • Intumescent coating
  • Fire protection
  • Thermal insulation