Environmentally benign few-bilayer intumescent nanocoating for flame retardant enzyme/plasma modified polyester fabric

The flammability of polyester textiles remains a significant challenge that must be overcome to allow their use in a variety of clothing and upholstery applications. In this work, water-based polyelectrolyte solutions composed of chitosan (CH) and pectin (P), as carbon-rich biomacromolecules, and mono ammonium phosphate (MAP) were deposited on enzyme/corona modified polyester via layer-by-layer (LbL) deposition. Four bilayers (BL) of 1% CH3/(1% P-30% MAP)4.2 renders the polyester fabric self-extinguishing in vertical flame testing. This recipe yields a 42.6% lower peak heat release rate and a nearly 40% reduction in the fire growth capacity, compared to uncoated polyester, as measured by micro cone calorimetry. The enzyme/corona modification, combined with the CH/(P-MAP) intumescent system, results in a very effective flame retardant treatment with few BL deposited.