writer：Wang LL, Zhang T, Yan HQ, Peng M, Fang ZP*
keywords：layer-by-layer assembly; transition metal inorganic salt; flame retardant; ramie fabric
source：期刊
specific source：J. Appl. Polym. Sci., 2013.6, 129(5): 2986-2997
Issue time：2013年

Transition metal ions doped flame retardant coatings were constructed on the surface of ramie fabrics by layer by layer (LbL) assembly technique to investigate the possible cooperative action that could improve the flame retardant efficiency. It is found that these functional coatings consisting of poly(vinylphosphonic acid) (anionic layer) and branched polyethylenimine/cupric or zinc ions (cationic layer) remarkably improved the fire retardancy of ramie fabrics. Attenuated total reflectance Fourier transform infrared spectroscopy and energy dispersive X-ray spectroscopy demonstrated the successful LbL assembly process and the incorporation of metal ions into the coating. Thermogravimetric analysis coupled with Fourier transform infrared spectrometry, vertical flame test and microscale combustion calorimetry confirmed the improved thermal stability and reduced flammability of coated ramie fabrics. All results show that both metal ions doped flame retardant coatings not only increased dramatically the residues but also well retained the original weave structure and fiber morphology of ramie fabrics. The enhanced flame retardant efficiency may be caused by the lower decomposition temperature of the flame retardant coating promoted by cupric and zinc ions, as a result, help the flame retardant activity to take place in advance.