Buffer induced ionically crosslinked polyelectrolyte treatment for self-extinguishing polyester

Over 60 million tons of polyethylene terephthalate (PET) fibers are produced annually for clothing, upholstery, linens, and carpeting. Despite its widespread use, the versatility of PET is constrained by its flammability, which poses a particular fire hazard to homes with synthetic furnishings. To mitigate this fire risk, a polyelectrolyte complex (PEC) solution composed of polyallylamine hydrochloride and poly(sodium phosphate) is deposited onto the surface of 100% polyester fabric to render it self-extinguishing and eliminate melt dripping. A buffered solution of acetic acid, citric acid, or formic acid is used to initiate ionic complexation, rendering the PEC water resistant. Buffer identity affects deposition, but does not significantly influence the intumescent mechanism. This rapidly deposited aqueous coating primarily operates by facilitating production of an insulating char layer that limits the heat release and degradation of polyester into volatile byproducts.