Amine Salt Thickening of Intumescent Multilayer Flame Retardant Treatment
Layer-by-layer assembly often requires numerous deposition steps to obtain a suitable thickness for an effective flame retardant nanocoating. In an effort to make this technique more industrially feasible, an amine salt is added to the rinsing steps of a chitosan/sodium hexametaphosphate (CH/PSP) multilayered system to help facilitate thicker growing films with self-extinguishing capability and fewer processing steps. Cotton fabric coated with CH/PSP is rinsed in water baths containing tris(hydroxymethyl)aminomethane [THAM] and compared to control samples rinsed with deionized water. Only 10 bilayers of the CH/PSP system rinsed with THAM are required to achieve self-extinguishing behavior and pass a vertical flame test, while 15 bilayers of the control system are needed to achieve similar results.
S. Lazar, B. Eberle, E. Bellevergue, J.C. Grunlan, Ind. Eng. Chem. Res. 2020, 59, 2689-2695.