Application of poly(diphenolic acid-phenyl phosphate)-based layer by layer nanocoating in flame retardant ramie fabrics

Poly(diphenolic acid-phenyl phosphate) [poly(DPA-PDCP)], obtained from diphenolic acid (a well-known biomass chemical), was used together with polyethylenimine (PEI) to construct a flame retardant surface coating for ramie fabric using layer-by-layer self-assembly. Attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and scanning electron microscope (SEM) equipped with an energy dispersive X-ray spectrometer (EDX) were used to confirm the successful formation of layer by layer assembly. Assessment of the thermal and flammability properties for poly(DPA-PDCP)/PEI-coated ramie fabrics showed that the thermal stability, flame retardancy, and residual char were enhanced as the concentration of poly(DPA-PDCP) and the BL number in the LbL process increased as well as the treatment of KH550 was applied. SEM and EDX analysis of the char residue confirmed further the intumescent flame retardant mechanism. This work demonstrated the great potentials of poly(DPA-PDCP)/PEI flame retardant nanocoating constructed by LbL assembly method in the application of ramie fabric. (c) 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44795.