For the first time, Layer-by-layer (LbL) assemblies made with carbon nanofiber (CNFs) are shown to improve the fire performance of polyurethane foam. The (359 ± 36) nm thick four bilayer coating of polyethyleneimine/CNF (cationic layer) and poly(acrylic acid) (anionic layer) contains (51 ± 1) mass fraction % CNFs. This coating completely covers the entire internal and external surfaces of the porous foam. Even though the microscopic CNF distribution was non-uniform, the macroscopic CNF network armor that was generated from this LbL process significantly reduced the flammability of the foam (55% ± 6% reduction in total heat release and peak heat release rate). This reduction is 50% better than previously reported for CNF-filled foam and 12% to 47% greater than the other most commonly used technologies for reducing foam flammability.
Pub Type: Journals
Layer-by-layer assembly, thin films, carbon nanofibers, polyurethane foam, Cone Calorimetry, flammability, soft furnishings