Engineered mycelium for fireproofing flammable FRP composites

Composites find increasing applications in various industries, including construction, aerospace, automotive, and marine, owing to their advantageous properties such as high strength-to-weight ratio, stiffness, fatigue endurance, corrosion resistance, and low thermal expansion. However, their utilisation in extreme thermal conditions poses a challenge, as elevated temperatures can lead to the degradation of mechanical properties due to the softening and decomposition of the polymer matrix, releasing volatiles that promote combustion and produce smoke and toxic gases. With the growing use of composites in commercial applications, the risk of fire accidents cannot be ignored. Flame retardant additives have been integrated into composites to preserve mechanical performance under high temperatures. Halogenated flame-retardants, previously preferred, are now avoided due to environmental and toxicity concerns. Alternatives like phosphorus and nitrogen-based flame retardants still pose health and environmental challenges. To address this, bio-derived flame retardants, such as fungal mycelium, are explored as sustainable and non-toxic alternatives. This project investigates the development of bio-derived fungal mycelium as fireproofing materials for composites. Mycelium, the root-like structural filament of fungi, possesses intrinsic flame-retardant characteristics due to the presence of chitin and the ability to form carbonaceous char. While mycelium has shown potential as a biomass binder in composites, its use with indigested or residual flammable agriculture biomass impacts both mechanical and fire retardation properties. This project explores the use of liquid substrates, like molasses, to cultivate pure mycelium without residual biomass. This project significantly advances the understanding of the interaction between bioderived mycelium flame-retardants and GFRP composites, paving the way for sustainable fire safety solutions. The outcomes contribute to the evolution of bio-derived mycelium thermal protection materials for fire-threatened infrastructure, showcasing the potential of mycelium to enhance the thermal stability of polymer matrix composites and reduce the combustibility of flammable composites.