Recent Development of Fire Retardancy of Fiber-Reinforced Laminated Composites Utilizing Carbon Nanofiber Sheets

Recently, various nanoparticles have been paid attention as novel fire retardants. Although it has been pointed out that carbon nanofibers (CNF) have lower efficiency of fire retardancy through directly dispersing CNF in polymer resins, the cost advantage of CNF arouse our interest of exploring novel methods to improve their fire retardancy. In our work, CNF were fabricated into various freestanding carbon nanofiber sheets (CNS). They were integrated into glass fiber mat (GFM)/polyester composites through different ways. Their fire retardancy was evaluated with cone calorimeter test at an external radiated heat flux of 50 kW/m². The results show that one single layer of CNS did not benefit the improvement of fire retardancy on the top surface of composites. But, multi-plies CNS with alternate arrangement with GFM or CNF containing clay particles on the top surfaces could significantly improve the fire retardancy of composites.