This presentation will highlight new flame retardant (FR) nanocoating systems, prepared from aqueous polyelectrolyte solutions, developed within the Polymer NanoComposites (PNC) Laboratory (http://nanocomposites. tamu.edu/). In an effort to create an environmentally-friendly flame retardant system for foam and fabric, thin films were assembled layer-by-layer (LbL) using "green" materials obtained from completely renewable sources. Ten bilayers of pH 6 chitosan (CH), as the cationic layer, and pH 10 montmorillonite (MMT) as the anionic layer, were deposited on flexible polyurethane foam (30 nm thick and added 4 wt%). When cut open after direct flame from a propane torch for 10 seconds, white undamaged foam was revealed under a thin black char layer. In related work on foam, vermieulite (VMT) ciay was layered with CH, followed by layers of an intumescent system comprised of CH and APP (or poly sodium phosphare [PSP]). This 'stacked' FR system (i.e., intumescent layers on top of clay layers) reduced the foam's peak heat release rate by 66%. Just two clay layers provide enough support to the foam during heating to allow intumescence to occur prior to collapse, creating our best result to-date. Another recipe, involving layers of poly(vinylsulfonic acid sodium salt) and CH, completely extinguishes the flame from a butane torch on this same foam. This exciting result is due to a 'gas blanket' effect in which the coating releases small amounts of NH3, S02 and H20 that prevent oxygen from reaching the foam surface. On cotton fabric, we will show how a single aqueous polyelectrolyte suspension, made with polyethylenimine and PSP. Weight gain on the fabric is controlled by the time in solution and the treated fabric is able to pass standard vertical flame testing. This has been dubbed the ''OnePot" system, which was inspired by LbLnanocoating, but is more efficient due the need for only a single layer.
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