Enhanced Flame Retardancy of Polymer-Carbon Nanotube Multi-Layer Coatings

초록

The polymer nanocomposites were prepared via layer-by-layer assembly and their physical and flame retardancy were analyzed. Chitosan-catechol (CH-C)/montmorillonite (MMT) thin films were fabricated by alternately depositing positively charged CH-C and negatively charged MMT in an aqueous solution. CH-C/carbon nanotube (CNT)-MMT nanocomposites were assembled with the CNT stabilized in MMT aqueous solutions. Both polymer nanocomposites exhibited that the film thickness increased linearly with the number of layers deposited, and that nano-scaled MMT and CNT structures were visualized using atomic force microscopy (AFM) and scanning electronic microscope (SEM). The flame retardancy of CH-C/MMT and CH-C/CNT-MMT assemblies were confirmed by vertical/horizontal flame tests and cone calorimeter. Layered inorganic MMT creates the char upon the flame, which impedes combustion and consequently imparts flame retardancy. By introducing CNT into the nanocomposites, the flame retarding characteristics in CH-C/CNT-MMT films were further improved, which is most likely due to the strong interaction between MMT and CNT and high thermal stability of CNT.

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