Flame-retardant, non-irritating and self-healing multilayer films with double-network structure

Flame-retardant, non-irritating, and self-healing double-network films based on host-guest interaction were prepared on paper via layer-by-layer (LbL) assembly. The multilayer films are composed of poly (acrylic acid)-adamantanamine/ammonium polyphosphate-cross-poly (ethylenimine)-β-cyclodextrin (PAA-AD/APP-co-PEI-β-CD). After a mild reaction between APP and PEI-β-CD polymers, PAA-AD and APP-co-PEI-β-CD polymers form the novel double-network films via the host-guest interaction. The novel film can produce a self-healing surface without any initiating agents. Besides, when directly exposed to a flame, such films will generate foam char layers because of the intumescent effect, and will endow the print paper with a self-extinguishing property. The fire protection of the coatings was intensively investigated by a fire protection test, scanning electron microscopy (SEM), compressive strength test, thermogravimetric analysis (TGA), and real-time Fourier transform infrared spectroscopy (FTIR). The fire resistant films were found to have the best fire-protection effect under the low-cost and eco-friendly conditions. The films show potential applications as multifunctional advanced commercial supplies, such as papers, textiles, and wood.