Construction of -FeOOH nanorod-filled layer-by-layer coating with effective structure to reduce flammability of flexible polyurethane foam

The -FeOOH nanorod-filled coatings were deposited onto flexible polyurethane foam by layer-by-layer assembly technique to reduce its flammability. The coatings were constructed by two assembly systems: one was bilayer system, which was comprised of polyethylenimine and -FeOOH nanorods; other one was trilayer system, which was comprised of polyethylenimine, -FeOOH nanorods, and sodium alginate. Scanning electron microscopy images indicated that the randomly oriented and entangled network structure can only be observed for the coating that assembled by trilayer system. Cone calorimetry test revealed that the coating assembled by trilayer system can lead to significant reduction in peak heat release rate compared with those of control foam, 61.8% peak heat release rate reduction ever occurred to the eight trilayers coated sample, but the coating assembled by bilayer system has slight reduction (<20%). The result is attributed to trilayer approach being beneficial to fabricate coating with sufficient thickness to protect the underlying foams during burning. Copyright (c) 2016 John Wiley & Sons, Ltd.