Dual modification of EVA by long chain phosphaphenanthrene grafted MXene and black phosphorene nanosheets for simultaneously enhanced thermal stability and flame retardancy

Abstract

It is significant to develop high-efficient fire retardants all the time. Ethylene vinyl acetate (EVA) features flammability and poor fire resistance ability, which severely hindered its extensive application with advanced requirements. Herein, a novel strategy was proposed to combining long chain phosphaphenanthrene grafted MXene (DPP-MXene, also donated as DM) and black phosphorene nanosheets (BP) with EVA to fabricate EVA/DMBP nanocomposites with high fire resistance. Thermogravimetric analysis (TGA) proved that DMBP synergistic system can significantly improve the thermal stability and char forming ability of EVA as proved by delayed thermal decomposition temperatures. The combustion test results suggested that the addition of 3 wt. % DMBP into EVA matrix can induce the EVA/DMBP-3 composites with favorable flame resistance property, the UL-94 V-0 rating and limiting oxygen index (LOI) value (26.7 %) was achieved for the EVA/DMBP-3 components, and significantly decrease in total heat release (THR) (21.5 %) and peak heat release rate (PHRR) (48.1 %) were achieved by addition of 3 wt. % DMBP into EVA elastomer, indicated its incombustible nature. Furthermore, it was found that the incorporation of DMBP synergistic system only yielded the EVA/DMBP-3 composites with slight reduction of the tensile strength and elongation at break as compared to neat EVA. The high efficiency of the prospect flame retardant provided a competitive candidate material for EVA towards wide applications.