Rubber toughened flame retardant (FR) polyamide 11 nanocomposites Part 2: synergy between multi-walled carbon nanotube (MWNT) and MMT nanoclay

Abstract In the previous study, flame retardant (FR) polyamide 11 (PA11) nanocomposites formulations designed for selective laser sintering (SLS)were prepared and characterized. The SEBS-g-MA elastomer successfully improved the material’s ductility. Although the nonhalogenated FR additives and montmorillonite (MMT) nanoclay successfully decreased the heat release capacity (HRC) and peak heat release rate (pHRR) as characterized by microscale combustion calorimeter (MCC). None of the rubber toughened formulations achieved UL 94 V0 rating, which is a bench mark for many FR polymer applications. As part two of this study, we explored the synergism between two nanoparticles, nanoclay and multi-walled carbon nanotubes (MWNTs), to see whether better FR properties can be achieved. TEM micrographs indicate that both nanoclay and MWNTs achieved high level of dispersion. Flammability results showed that all formulations achieved UL 94 V0 rating, which is a significant improvement from the previous formulations without MWNTs. Char morphology characterization indicated that a solid carbonaceous char layer was reinforced by nanoclay and MWNTs.