Strengthened interface as flame retarding belt: Compatibilized PLLA/PP blends by reactive boehmite nanorods

Herein, we proposed a new strategy to enhance compatibility and flame retardancy of the immiscible and flammable polylactic acid (PLLA)/polypropylene (PP) blend materials simultaneously. It is found that the boehmite nanorods are located at the PLLA-PP interface by in-situ reactions and the compatibility between phases is greatly improved, resulting in significant enhancement of mechanical properties and flame retardancy: tensile strength and elongation at break of the blends with 7 wt% reactive nanorods are 163% and 601% higher than that without nanorods, respectively. Meanwhile, the peak heat release rate (PHRR) decreases 51.4% and limiting oxygen index (LOI) increases 22.6%. The synergetic improvements are directly attributed to the strengthened interface and the interface takes the role of the flame retarding belt. The research opens a new avenue to fabricate non-halogen flame retardant multicomponent polymer materials with simultaneously enhanced mechanical properties. [Display omitted] •Ternary Poly(L-lactic acid)/Polypropylene/boehmite nanorods nanocomposites were prepared.•Epoxide groups modified boehmite nanorods are thermodynamically located at the PLLA/PP blend interface by the in-situ reactions.•The interfacially located nanorods improve the mechanical properties and flame retardancy of the PLLA/PP blends simultaneously.