Effect of Graphene on Flame Retardancy of Graphite Doped Intumescent Flame Retardant (IFR) Coatings: Synergy or Antagonism

Abstract

A comparative study between graphene and modified graphene oxide (mGO) on the flame retardancy of graphite doped intumescent flame retardant (IFR) coatings is preliminarily investigated by cone calorimeter (CC), XRD, and SEM, with the final aim of clarifying the interactions between different graphenes and graphite doped coatings (polyester resin-ammonium polyphosphate-urea-pentaerythritol). The CC results determine that graphene exerts an obviously antagonistic effect on flame resistance, evidenced by the increased peak heat release rate (p-HRR) of 56.9 kW·m−2 for SD8+graphene (sample coating contains graphite with a particle size of 8 μm and 0.5 wt.% graphene as dopant), which increased by 80.6% compared with SD8 (coating contains graphite with a particle size of 8 μm); substitution with graphene or mGO imparts an acceleration of fire growth, because graphene inertness improves the viscosity of melting system, evidenced by the cracked appearance and porous structure of SD8+graphene. However, the higher reactivity of mGO favors the combustion; the barrier effect inhibits the transfer of mass and heat simultaneously, leading to a slight influence on flame retarding efficiency.

New pivot for investigating flame‐retarding mechanism: Quantitative analysis of zinc phosphate doped aliphatic waterborne polyurethane‐based intumescent coatings for flame‐retarding plywood

“…Table 2 briefly summarizes the combustion parameters of samples during the whole combustion process. Because the FGI and FPI are the most important indicators to evaluate the flashover propensity of combustible materials, 3‐5 which is consensual and widely used‐avenue to analyze this issue. Meanwhile, the S2 exhibits the lowest p‐HRR of 111.9 kW m −2 and FGI of 0.45 kW m −2 s −1 , as well as the highest FPI of 0.71 second·m 2 kW −1 and residue weight of 40.55 wt% among all samples.…”

“…1,2 However, the flame resistance of IFRCs needs to be further improved before being in extensive applications, and also the water-resistance and opacity of hybrid coating need to be optimized simultaneously. Our previous investigations have attempted to enhance the flame resistance of IFRCs by incorporating inorganic silicate 3 or graphite, 4,5 but the coating color is inherent gray and non-transparent. Meanwhile, the main methodologies developed to fabricate transparent nanocomposites mainly contain four categories: the blending of nanoparticles and transparent polymer; the in-situ polymerization in the presence of pre-formed nanoparticles; the in-situ nanoparticle synthesis in a pre-formed polymer matrix; and finally the simultaneous polymerization and in situ nanoparticle synthesis.…”

Ecological Ammonium Thiocyanate-Modified Geopolymeric Coating for Flame-Retarding Plywood

“…The thickener and film-forming agent, polyacrylamide (PAM), was synthesized by the Shanghai reagent factory in China. EG served as the charring fortifier [15] and was fabricated by the Qingdao chemical group in China with a volume-expansion rate of 300 mL•g −1 and an average particle size of 48 µm. The second-class flame-retarding plywood was produced in the Xi'an timber processing plant.…”

“…The heat release rate (HRR), time to ignite (TTI), the peak heat release rate (pHRR), time to pHRR (T p ), O 2 concentration and smoke temperature in exhaust smoke, and time to the cessation of flaming (T b ) were recorded in real time. The fire performance index (FPI, FPI = TTI/pHRR) and fire growth index (FGI, FGI = pHRR/T p ), were the most important indexes to distinguish the flame-retardant efficiency [7,13,15], the sample with a higher FPI and lower FGI corresponded to a stronger flame resistance.…”

Graphene Oxide and Vermiculite Clay Combinations to Produce Enhanced Flame Retardant Polypropylene Composite with Low Magnesium Hydroxide Loading

“…[ 17,18 ] It is reported that graphene and GO at very low loadings (less than 1 wt%) can provide significant mechanical reinforcement to materials used to provide high FR. [ 19‐22 ] GO has been demonstrated that imparts FR characteristics to polymer composites mainly because it can improve the polymer thermal stability and delay its ignition. It also can inhibit fire from spreading and reduce the heat release rate (HRR).…”