Air‐Stable Polyphosphazene‐Functionalized Few‐Layer Black Phosphorene for Flame Retardancy of Epoxy Resins

Abstract

Similar to graphene, few‐layer black phosphorus (BP) features thermal stability, mechanical properties, and characteristic dimension effects, which has potential as a new member of nanofillers for fabricating polymer nanocomposites. Herein, a cross‐linked polyphosphazene‐functionalized BP (BP‐PZN) is developed with abundant –NH2 groups via a one‐pot polycondensation of 4,4′‐diaminodiphenyl ether and hexachlorocyclotriphosphazene on the surface of BP nanosheets. Whereafter, the resulting BP‐PZN is incorporated into epoxy resin (EP) to study the flame‐retardant property and smoke suppression performance. Cone results show that the introduction of 2 wt% BP‐PZN distinctly improves the flame‐retardant property of EP, for instance, 59.4% decrease in peak heat release rate and 63.6% reduction in total heat release. The diffusion of pyrolysis products from EP during combustion is obviously suppressed after incorporating the BP‐PZN nanosheets. Meanwhile, the EP/BP‐PZN nanocomposites exhibit air stability after exposure to ambient conditions for four months. The air stability of the BP nanosheets in EP matrix is assigned to surface wrapping by PZN and embedded in the polymer matrix as dual protection. As a new member of the 2D nanomaterials, BP nanosheets have potential to be a new choice for fabricating high‐performance nanocomposites.

Fabrication of ZIF‐8@Polyphosphazene core‐shell structure and its efficient synergism with ammonium polyphosphate in flame‐retarding epoxy resin

“…When 3 wt% ZIF‐8@PZN and 18 wt% APP were added into the EP, similar crease morphology was still obtained (Figure C). This phenomenon indicates that after PZN is coated on the surface of ZIF‐8, the compatibility and interface interaction of ZIF‐8@PZN with EP are greatly increased because of the network structure of the ‐PN‐ bonds of PZN itself and the presence of amino reactive groups …”

Nanoreinforcements of Two-Dimensional Nanomaterials for Flame Retardant Polymeric Composites: An Overview

“…Mono or multi-layer BP is a two-dimensional nanomaterial with distinct physical/chemical properties due to dimensionality effects [21,68]. BP can catalyze the formation of char and capture free radicals, and its unique layered structure can also serve as a physical barrier for insulation from heat and oxygen during the combustion process [115]. fabricating EP-based nanocomposites with both superior TC and ame retardancy [118].…”

“…[55]. (e) Black phosphorus [56]. (f) Graphene with (I) Zigzag and armchair edges, (II) Monovacancy, (III) Local structure of a curved graphene sheet [57].…”

Cross‐Linked Polyphosphazene Hollow Nanosphere‐Derived N/P‐Doped Porous Carbon with Single Nonprecious Metal Atoms for the Oxygen Reduction Reaction

“…[2] Using different monomers,for instance,4,4'-(hexafluoroisopropylidene)diphenol,m elamine,a nd fluorescein (FL), the products would be endowed with different properties such as super-hydrophobicity,f lame retardance,a nd fluorescence. [3] In addition, products with different morphologies including nanotubes,n anofibers,a nd microspheres can be obtained by tuning the reaction conditions. [4] To date,most of the cross-linked polyphosphazene microspheres were synthesized using other inorganic/organic spheres as sacrificial templates,r esulting in hollow structures.…”