Facile Synthesis of a Novel Bio-Based P-N Containing Flame Retardant for Effectively Reducing the Fire Hazards of Epoxy Resin

Abstract

In this work, a bio-based flame retardant (Cy-HEDP) was synthesized from cytosine and HEDP through a facile salt-forming reaction and embedded into epoxy matrix to improve the flame retardancy and smoke suppression performance. The product Cy-HEDP was well characterized by FTIR, 1 H and 31 P NMR and SEM tests. On the basis of the results, by adding 15 wt% Cy-HEDP, the EP 15 can pass UL-94 V-0 rating, and the total smoke production (TSP) as well as total heat release (THR) can be decreased by 61.05% (from 22.61 to 8.7 m 2 /m 2 ) and 39.44% (from 103.19 to 62.50 MJ/m 2 ) in comparison to the unfilled EP, reflecting the attenuated smoke toxicity and impeded heat generation. According to the analysis results of residual char, it can be concluded that Cy-HEDP possessed the ability to promote the formation of continuous and dense char layers, which would be a physical barrier to insulate oxygen and prevent heat feedback during the combustion of EP. This work provide inspiration towards developing bio-based flame retardant, probably extending the prospects to other polymeric material system.

Eco‐Friendly One‐Pot Supramolecular‐Assembly of P‐N Flame Retardant for Fire‐Safe Epoxy Resin

“…Compared with the reported EP composites with phosphorus‐nitrogen flame retardants (Figure 4g), [ 14–19,22,38 ] the advantages of supramolecular ATPFR were revealed. Overall, with a comparatively low loading (5 wt%), ATPFR can bestow the EP with strong flame retardancy (UL‐94 V‐0 grade).…”

“…[ 10–13 ] Among them, nitrogen‐phosphorus flame retardants have shown outstanding properties (e.g., high safety, low toxicity, good stability) and are favored. [ 14–19 ] He et al. [ 20 ] prepared a flame retardant (named BMP) with the phosphaphenanthrene and rigid imine structures via an addition reaction.…”

“…[10][11][12][13] Among them, nitrogen-phosphorus flame retardants have shown outstanding properties (e.g., high safety, low toxicity, good stability) and are favored. [14][15][16][17][18][19] He et al [20] prepared a flame retardant (named BMP) with the phosphaphenanthrene and rigid imine structures via an addition reaction. The addition of 10 wt% BMP could enable the EP thermosets to achieve the V-0 level of the flammability UL-94 tests, and increase the limiting oxygen index (LOI) value to 35%.…”

Surface Flame-Retardant Systems of Rigid Polyurethane Foams: An Overview

“…With the development of society, people have put forward higher requirements for environmentally friendly, safe, and efficient IFRs. Research on the production of IFRs from biomass materials as raw materials has received wide attention due to their green, renewable, and degradable characteristics [ 44 , 63 , 64 ].…”

Enhancing flame retardancy of poly(lactic acid) with a novel fully biobased flame retardant synthesized from phytic acid and cytosine

“…Yu et al 33 synthesized a flame retardant with cytosine and pyrophosphate to improve the performance of polypropylene together with pentaerythritol, and the composite achieved a UL-94V-0 rating, outperforming commercial ammonium polyphosphate. Li et al 34 prepared a biobased flame retardant (Cy-HEDP) using cytosine and hydroxyethyldiphosphonic acid. After adding 15 wt% Cy-HEDP into epoxy resin, the flame-retardant rating of composite reached UL-94V-0.…”