Fabrication of an novel NiCo‐based bimetallic hydroxide encapsulated with polyphosphazene with simultaneously improved the flame retardancy and smoke suppression for polypropylene

Abstract

The polyphosphazene (PZN) with dual functions of “surface modifier” and “flame‐retarded synergistic agent” was introduced as the “shell” in order to improve the compatibility and flame retardancy property of NiCo‐based bimetallic hydroxide (NiCo‐BH). In this study, a novel core‐shell nanostructures flame retardants (PZN@NiCo‐BH) was synthesized, the resulting PZN@NiCo‐BH was further incorporated into PP to investigate the mechanical property, flame retardancy and smoke suppression performance. Chemical structure and morphology of PZN@NiCo‐BH were characterized by XRD, FT‐IR, SEM, TEM, WCA and TG‐DTG, and the results have shown the successful preparation of the well‐designed PZN@NiCo‐BH. Moreover, LOI, UL‐94 and cone calorimetry measurements results further confirmed the superb flame retardancy and smoke suppression of the synthesized PP/PZN@NiCo‐BH composites with a LOI value of 29.5% in the UL‐94 V‐0 rating, and 56.3% reduction in total smoke production (TSP). Meanwhile, based on the analysis of the combustion residues, possible mechanism of flame retardancy was also proposed.