Phosphorus-functionalized MXene nanohybrid toward fire-resistant, mechanically reinforced and toughened PLA composites

The development of biodegradable polymers with excellent flame retardancy and mechanical robustness remains a critical challenge for sustainable materials. In this paper, a novel MXene nanohybrid (MXene-PPD) was prepared by grafting organic phosphorus-containing polymer onto MXene using interface engineering strategy. The incorporation of merely 2.5 wt % MXene-PPD into poly(lactic acid) (PLA) matrix remarkably enhances its flame retardancy, elevating the limiting oxygen index (LOI) from 19 % to 23.1 % and achieving a UL-94 V-0 rating. Cone calorimetry analysis demonstrates a 11 % reduction in peak heat release rate (PHRR) for the PLA/2.5MXene-PPD composite compared to neat PLA. The superior interfacial adhesion of MXene-PPD in PLA composites facilitates efficient stress transfer, resulting in demonstrated enhancements of up to 13.6 % in tensile strength and 13.9 % in impact resistance compared to unmodified PLA. These findings highlight the potential of MXene-PPD as an effective additive for developing high-performance biodegradable polymers.