Flame-retardant Polyamide 11 and 12 Nanocomposites: Thermal and Flammability Properties

Abstract

Polyamide (nylon) 11 (PA11) and 12 (PA12) were melt-blended, dispersing low concentrations of nanoparticles, namely nanoclays (NCs), carbon nanofibers (CNFs), and nanosilicas (NSs) via twin-screw extrusion. To enhance their thermal and flame-retardant (FR) properties, an intumescent FR additive was added to the mechanically superior NC and CNF PA11 formulations. For neat and nanoparticle-reinforced PA11 and PA12, as well as for PA11 reinforced by both intumescent FR and select nanoparticles (NC or CNF), decomposition and heat deflection temperatures were measured, as were the peak heat release rates while burning the composites. All PA11 polymer systems infused with both nanoparticles and FR additive had higher decomposition temperatures than those infused with solely FR additive. For the PA11/FR/NC polymer blends, only the 20 wt% FR and 7.5 wt% clay formulation passed the UL 94 V-0 requirement, while all PA11/FR/ CNF formulations passed UL 94 V-0 requirement.