Intumescent Fire Retardant Coating Research Articles

Smoke Suppression Properties of Fe2O3 on Intumescent Fire-Retardant Coatings of Styrene–Acrylic Emulsion

The intumescent flame-retardant coatings were prepared using ammonium polyphosphate (APP), pentaerythritol (PER), melamine (MEL), styrene–acrylic emulsion, and iron oxide yellow (FeOOH) as the base material. A cone calorimeter (CCT), smoke density meter (SDA), and scanning electron microscope (SEM) were employed to investigate the smoke suppression and flame retardancy of FeOOH in intumescent fire-retardant coatings. The thermal degradation performance of intumescent fireproofing coatings with varying FeOOH content was investigated through thermogravimetric analysis (TGA). The structure of the carbon slag in the CCT test was analyzed using a scanning electron microscope (SEM). The results of the cone calorimeter (CCT) experiments demonstrated that FeOOH significantly reduced the heat release rate (HRR), total heat release rate (THR), smoke production rate (SPR), and total smoke release rate (TSR) of the coating, while simultaneously increasing the carbon residue rate of the coating. The smoke density analysis (SDA) results demonstrate that adding FeOOH can effectively reduce smoke generation, regardless of whether a pilot flame is used. TGA results demonstrate that FeOOH can enhance the weight of coke residue at elevated temperatures. SEM results indicate that incorporating FeOOH resulted in a more compact coke residue. According to these findings, among all the samples, those containing 2 wt% FeOOH showed low levels of HRR, THR, SPR, and TSR and high levels of SOD, which proves that FeOOH can be used as a smoke inhibitor in flame-retardant coatings.

Synergistic effect of phytic acid and eggshell bio-fillers on the dual-phase fire-retardancy of intumescent coatings applied on cellulosic substrates

Cellulosic substrates, including wood and thatch, have become icons for sustainable architecture and construction, however, they suffer from high flammability because of their inherent cellulosic composition. Current control measures for such hazards include applying intumescent fire-retardant (IFR) coatings that swell and form a char layer upon ignition, protecting the underlying substrate from burning. Typically, conventional IFR coatings are opaque and are made of halogenated compounds that release toxic fumes when ignited, compromising the roofing's aesthetic value and sustainability. In this work, phytic acid, a naturally occurring phosphorus source extracted from rice bran, was used to synthesize phytic acid-based fire-retardants (PFR) via esterification under reflux, along with powdered chicken eggshells (CES) as calcium carbonate (CaCO3) bio-filler. These components were incorporated into melamine formaldehyde resin to produce the transparent IFR coating. It was revealed that the developed IFR coatings achieved the highest fire protection rating based on UL94 flammability standards compared to the control. The coatings also yielded increased LOI values, indicative of self-extinguishing properties. A 17 °C elevation of the IFR coating's melting temperature and a significant ∼172% increase in enthalpy change from the control were observed, indicating enhanced fire-retardancy. The thermal stability of the coatings was improved, denoted by reduced mass losses, and increased residual masses after thermal degradation. As validated by microscopy and spectroscopy, the abundance of phosphorus and carbon groups in the coatings' condensed phase after combustion indicates enhanced char formation. In the gas phase, TG-FTIR showed the evolution of non-flammable CO2, and fire-retardant PO and P–O–C. Mechanical property testing confirmed no reduction in the adhesion strength of the IFR coating. With these results, the developed IFR coating exhibited enhanced fire-retardancy whilst remaining optically transparent, suggestive of a dual-phase IFR protective mechanism involving the release of gaseous combustion diluents and the formation of a thermally insulating char layer.

Thermo‐mechanical performance of wolframite mineral reinforced siloxane‐modified epoxy‐based intumescent coating for structural steel

AbstractThis study investigated the effects of wolframite on the fire resistance and adhesion strength of intumescent fire‐retardant coating (IFRC) using a siloxane‐modified epoxy binder. The modification of bisphenol A epoxy was confirmed via Hydrogen‐Nuclear Magnetic Resonance Analysis. The IFRC samples were developed with wolframite (0.25–2.0 wt%) and evaluated for Thermogravimetric analysis (TGA), fire resistance test, furnace fire test for char expansion, morphology and chemical composition, adhesion test and water immersion test. This study identified a coating formulation containing 2.0 wt% of wolframite that showed 57.2% improvement in the residual weight, substrate temperature of 176.7°C and produced a compact char. Field Emission Scanning Electron Microscopy showed that the addition of wolframite reduced pore size thereby increasing the char strength. X‐ray diffraction identified iron neodymium compounds in the char layers, which lowered the pore size resulting in lower substrate temperature. X‐ray photoelectron spectroscopy indicated that the antioxidant capability and the carbon content were increased by 6.9% and 50.3% respectively. The adhesion strength was reduced, however, was within the industrial standards of 2.07 MPa. The water immersion test showed a maximum 66.7% reduction (WF2.0) in the water permeation through the coating.

Research and manufacture water-based fire retardant coating mixture using graphene additive for natural wood

Intumescent fire-retardant coatings, especially water-based intumescent fire-retardant coatings, are increasingly attracting attention due to their environmentally friendly properties. In this work, we have successfully manufactured a water-based fire retardant coating mixture using graphene additive for natural wood with three main ingredients (ammonium polyphosphate acidifying agent, pentaerythritol carbonizing agent, melamine blowing agent), and some additives including graphene. We investigated the influence of graphene content on the fire retardant effectiveness of the mixture when coated on natural wood (pine wood) according to UL94-V standard. Test results show that the content of graphene contributes to enhancing the fire retardant effectiveness of the manufactured mixture. SEM imaging method was used to analyze and explain the test results. Some specifications of the manufactured mixture are also analyzed and evaluated. The findings of this research provide a solution to enhance fire resistance for natural wood structures using environmentally friendly materials.

Is titania acting as a synergist in intumescent fire retardant coatings designed for improving reaction to fire of wood?

Intumescent coatings based on ammonium polyphosphate (APP), are widely applied as passive fire protection. For flammable materials like wood, a rapid char expansion is needed to limit fuel gas release to the combustion zone and minimize reaction to fire. It is generally accepted that titanium dioxide (TiO2) improves the fire performance of coatings and acts as a synergist. This study discusses the role of TiO2 in intumescent coatings by investigation of real-time measurement of char expansion during heating, rheology, thermal analysis, cone calorimetry, and chemical composition by X-ray diffraction and IR spectroscopy under different TiO2 loadings. Results show that TiO2 enhance the rate of char expansion despite increased complex viscosity of the molten coating matrix. Further, thermal decomposition and onset of intumescent reactions remained unchanged by increased TiO2 loading which results in a lower final char height. Altogether, TiO2 acts as an incombustible filler reducing char expansion and not fulfilling the definition of a synergist in intumescent coatings for improving reaction to fire of wooden products.

Pyrolysis characteristics and reaction mechanism of intumescent fire-retardant coating with thermogravimetry/Fourier transform infrared analysis

A research of intumescent fire-retardant coating (IFRC) pyrolysis characteristics and reaction mechanism was conducted by thermogravimetric analysis coupled with Fourier transform infrared spectrometry analysis at various heating rates. The results demonstrate that the pyrolysis process of IFRC could be separated into two stages. In stage I, which occurs within the temperature range of 300–800 K, there is a mass loss of 8.5 %. The main gases released during this stage are NH3 and CH4. Moving on to stage II, which takes place within the temperature range of 800–1200 K, there is a significant mass loss of 42.9 %. The main gases released during this stage are CO2 and H2O. Through the use of FTIR spectra, the production amount of main four components ranked as follows: CO2 > H2O > CH4 > NH3. Especially, the reaction expressions were further speculated and proposed. Subsequently, the two aforementioned stages were utilized based on both model-free and model-fitting methods to ascertain the possible reaction mechanism.

Influence of nanoclay on the fire resistance properties of epoxy-based intumescent retardant coatings for steel plate

The intumescent retardant coating was fabricated by a combination of epoxy binder and flame-retardant ingredients for the steel plate. This paper investigates the influence of nanoclay content on improving fire properties of intumescent fire-retardant coatings. The fire performances of the coatings were determined by a fire test at 950oC for one hour. The coating degradation was characterized by Thermal gravimetric analysis (TGA). The morphology, composition of char was studied by Fourier transform infrared spectra (FTIR), scanning electron microscopy (SEM), and energy dispersive X-ray spectra (EDS). The results revealed that the intumescent coating containing 3 wt.% of nanoclay showed the best reduction in substrate temperature compared to the intumescent coating without nanoclay. The results also concluded that nanoclay increased fire protective performances of the intumescent coating.

Influence of Wind Speeds and Heating Exposures on the Thermal Insulation of Intumescent Fire-Retardant Coatings

Influence of Wind Speeds and Heating Exposures on the Thermal Insulation of Intumescent Fire-Retardant Coatings

Fabrication of Intumescent Fire-Retardant Coating for Structural Applications

Applicability of materials limited by the effect of flammability in case of any sudden incident. Worldwide protection of any structure from the fire is covered through intumescent fire resistant coatings since many past years. Purpose of this study is to prepare and to fabricate several intumescent fire retardant coatings (IFRC) using different proportions of materials per unit weight. Also to find most optimistic formulations and analyse the performance of intumescent fire retardant coatings (IFRC). On the basis of background studies 5 different materials were considered to prepare several formulations i-e Titanium dioxide (TiO2), Ammonium polyphosphate (APP), Zinc borate, Epoxy hardener, Kaolinite (Clay), Melamine (MEL) and Expandable Graphite (EG). IFRC formulations were applied on Mild Steel plates after its preparation Each formulation was subjected to a temperature of 700°C for a period of five minutes. The results revealed that the coatings, Out of 5 formulations of IFRC, IFRC-4 exhibited promising performance. It demonstrated excellent stability and adhesion at the elevated temperature, lasting for over five minutes. Additionally, its coating expanded up to four times the initial thickness. Heat Transfer rate was completely reduced.

Dual curing agents for optimized flame-retardancy and physico-mechanical properties of cycloaliphatic epoxy coating

Higher durability with excellent insulation properties is to be considered an important factor for the formulation of intumescent fire-retardant coating (IFR) against the external environment. In this work, two structurally different hardeners such as cycloaliphatic amine and polyamido amine were used for curing hydrogenated bisphenol-A epoxy resin (DGEHBA) to develop intumescent fire-retardant (IFR) coating for exterior applications. Initially, a differential scanning calorimetry study was carried out to estimate the curing kinetics of DGEHBA resin and the hardeners. The IFR coating was prepared by mixing fire-retardant fillers such as ammonium polyphosphate, pentaerythritol and melamine along with TiO2 pigment in DGEHBA resin. The prepared DGEHBA coating was mixed with two different hardeners individually and their combinations in different weight ratios to make a series of epoxy IFR coatings. The impact of curing on the protection ability and integrity of these coatings was evaluated by analyzing their thermal, fire retardance and physico-mechanical virtues. Furthermore, the coatings were also studied for accelerated aging in humidity, weatherometer, seawater immersion and salt spray chamber to deduce the sustainability of the coatings. We have demonstrated enhancement in both, physico-mechanical and fire-retardant properties by using the above prepared coating compositions.

Brand identification of transparent intumescent fire retardant coatings using portable Raman spectroscopy and machine learning

Transparent intumescent fire retardant coatings (IFRC) are widely used to protect ancient buildings and high-end furniture from fire. Currently, IFRC fraud has attracted considerable attention due to the lack of efficient techniques to detect the identity of IFRC products. In this paper, we use Raman spectroscopy and machine learning to identify IFRC brands. A total of 135 transparent IFRC samples of 6 common brands were prepared and scanned using a portable Raman spectrometer. The obtained spectra were pre-processed to remove unwanted variation and classified using partial least squares discriminant analysis (PLS-DA) and kernel extreme learning machine (K-ELM). The accuracies achieved by PLS-DA and K-ELM were 0.978 and 0.993, respectively. In addition, important variables were determined based on the regression coefficients of PLS-DA. The results demonstrate that portable Raman spectroscopy combined with machine learning is a viable approach for rapid, on-situ and low-cost identification of IFRC brands.

Fabrication of Polypyrrole-Decorated Tungsten Tailing Particles for Reinforcing Flame Retardancy and Ageing Resistance of Intumescent Fire-Resistant Coatings.

Polypyrrole-decorated tungsten tailing particles (PPY-TTF) were prepared via the in situ polymerization of pyrrole in the presence of tungsten tailing particles (TTF), and then carefully characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and thermogravimetric analysis (TG) analyses. The effect of PPY-TTF on the flame retardancy, smoke suppression property and ageing resistance of intumescent fire-resistant coatings was investigated by a fire protection test, smoke density test and cone calorimeter test. The results show that PPY-TTF exerts excellent cooperative effect on enhancing the flame retardancy and smoke suppression properties of the intumescent fire-retardant coatings, which is ascribed to the formation of more cross-linking structures in the condense phase that enhance the compactness and thermal stability of intumescent char. The cooperative effect of PPY-TTF in the coatings depends on its content, and the coating containing 3 wt% PPY-TTF exhibits the best cooperative effect among the samples, showing a 10.7% reduction in mass loss and 35.4% reduction in flame-spread rating compared to that with 3% TTF. The accelerated ageing test shows that the presence of PPY-TTF greatly slows down the blistering and powdering phenomenon of the coatings, thus endowing the coating with the super durability of fire resistance and smoke suppression property. This work provides a new strategy for the resource utilization of tungsten tailing in the field of flame-retardant materials.

Synthesis and properties of a fire-retardant coating based on intercalated expandable graphite-modified cellulose for steel structures

In order to improve the performance of intumescent fire-retardant coatings for steel structures and to reduce the defects of the insulating carbon layer (Expanded carbon of fire retardant coatings after thermal degradation.), which usually undergoes cracking and falls off during combustion, we designed a new multifunctional intercalated expandable graphite-hydroxypropyl methylcellulose-uracil ketone (EG-HPMC-UPY) system by ultrasonication. Infrared analysis showed that the 2-ureido-4[1H]-pyrimidinone (UPY) groups were evenly distributed in the coatings to form a large number of reversible covalent and non-covalent bonds; this induced self-healing characteristics in the fire-retardant coatings. Scanning electron microscopy showed that EG expanded into worm-like shapes and intercalated with cellulose in the expanded carbonaceous layer, thus making it more compact and denser. The thermogravimetric analysis and cone calorimetry analysis showed that the weight loss rate and heat release rate of the fire retardant coating added EG-HPMC-UPY decreased by 13% and 65. During fire-resistance tests, it was observed that the temperature of the back and front of the steel plate coated with the fire-retardant coating containing intercalated EG-HPMC-UPY stabilized at 85 and 400 °C, respectively, which values are far lesser than the critical temperature of static equilibrium stability of structural steel (550 °C). Furthermore, the carbon layer formed during combustion did not fall off or crack, thus indicating the excellent flame retardancy potential of the developed coating. Finally, this study describes a new and effective way to improve the fire performance of intumescent fire-retardant coatings for steel structures.

Effect of titania, barite, and kaolinite fillers on char layer formation in water-based intumescent fire-retardant coatings

Effect of titania, barite, and kaolinite fillers on char layer formation in water-based intumescent fire-retardant coatings

Comparative Study of Fire Resistance and Char Formation of Intumescent Fire-Retardant Coatings Reinforced with Three Types of Shell Bio-Fillers.

Three types of shell bio-fillers, including eggshell (CES), conch shell (CHS) and clamshell (CMS), were prepared by cleaning, ultrasonication and pulverizing processes of biowastes, and then applied to intumescent fire-retardant coatings. The effects of shell bio-fillers with different polymorphs on the fire resistance and char-forming of intumescent fire-retardant coatings were investigated by cone calorimeter test, fire protection tests, smoke density test, thermogravimetric analysis (TG), and the fire resistance and char-forming mechanism of bio-fillers in intumescent fire-retardant coatings were proposed. The results show that three kinds of bio-fillers exert an excellent synergistic effect on enhancing the fire resistance and char-forming properties of the intumescent fire-retardant coatings, while clamshell has the best synergistic efficiency among the bio-fillers. Especially, IFRC-CMS coating containing 3 wt% clamshell shows the best fire protection performance and lowest smoke production and heat release, which offers an equilibrium backside temperature of 134.6 °C at 900 s, a flame-spread rating of 14.4, and a smoke density rating value of 22.8%. The synergistic efficiency of bio-fillers in the intumescent coatings depends on the polymorphs of CaCO3 in bio-fillers, and aragonite CaCO3 shows a higher synergistic efficiency compared to calcite CaCO3 and the mixture of aragonite and calcite CaCO3. The CMS composed of aragonite shows the best synergistic effect, CHS composed of aragonite and calcite comes second, and CES composed of calcite has the weakest synergistic effect.

Novel carbon nitride@polydopamine/molybdenum disulfide nanoflame retardant improves fire performance of composite coatings

An effective method to enhance the flame retardant capability of intumescent fire retardant (IFR) coatings by constructed a two-dimensional/two-dimensional (2D/2D) hybrid with good composition and microstructure. Herein, g-C3N4@PDA (CNP) was firstly obtained by loading graphite phase carbon nitride (g-C3N4) with bio-inspired polydopamine (PDA). Subsequently, a novel [email protected] hybrids was successfully prepared by loading molybdenum disulfide onto the CNP surface via a simple one-step hydrothermal method. Then, the obtained [email protected] was added to the IFR coating as a synergist to improve the flame resistance. Results indicated that the addition of 2 wt% [email protected] to the coating effectively accelerated the formation of the char layer and reinforced its thermal insulation properties. The [email protected]/EP sample exhibited the lowest backside temperature (179.6 ℃), the highest expansion ratio (10.53) and the most residual char (30.7%) by fire performance test, furnace test and TGA test. The combustion performance of the IFR coatings was investigated by cone calorimeter, and the results showed that the [email protected] hybrids based composite coating exhibited the lowest heat release rate (HRR), total heat release rate (THR), and total smoke production value (TSP). The mechanism investigations showed that the physical barrier effect and catalytic carbonization produced by [email protected] hybrids during the combustion process are the main reasons for the improved flame retardancy of epoxy coatings.

Fire Resistance, Thermal and Anti-Ageing Properties of Transparent Fire-Retardant Coatings Modified with Different Molecular Weights of Polyethylene Glycol Borate.

Four kinds of polyethylene glycol borate (PEG-BA) with different molecular weights were grafted into cyclic phosphate ester (PEA) to obtain flexible phosphate esters (PPBs), and then applied in amino resin to obtain a series of transparent intumescent fire-retardant coatings. The comprehensive properties of the transparent coatings containing different molecular weights of PEG-BA were investigated by various analytical instruments. The transparency and mechanical analyses indicate that the presence of PEG-BA slightly decreases the optical transparency of the coatings but improves the flexibility and adhesion classification of the coatings. The results from fire protection and cone calorimeter tests show that low molecular weight of PEG-BA exerts a positive flame-retarded effect in the coatings, while high molecular weight of PEG800-BA behaves against flame-retarded effect. Thermogravimetric and char residue analyses show that the incorporation of low molecular weight of PEG-BA clearly increases the thermal stability and residual weight of the coatings and generates a more compact and stable intumescent char on the surface of the coatings, thus resulting in superior synergistic flame-retarded effect. In particular, MPPB1 coating containing PEG200-BA exerts the best flame-retarded effect and highest residual weight of 36.3% at 700 °C, which has 57.6% reduction in flame spread rate and 23.9% reduction in total heat release compared to those of MPPB0 without PEG-BA. Accelerated ageing test shows that low molecular weight of PEG-BA promotes to enhance the durability of structural stability and fire resistance of the coatings, while PEG800-BA with high molecular weight weakens the ageing resistance. In summary, the fire-resistant and anti-ageing efficiencies of PEG-BA in the coatings depend on its molecular weight, which present the order of PEG200-BA > PEG400-BA > PEG600-BA > PEG800-BA.

Highly thermally stable zirconium oxide deposited layered double hydroxide for enhancing flame retardancy of waterborne epoxy coatings

Inspired by the multifunctional adhesion ability of poly dopamine (PDA), ZrO2 and aluminum magnesium hydroxide (LDH) were combined by PDA, which increased the function of this material in intumescent fire retardant (IFR) coatings. Briefly, PDA was coated on the surface of LDH to improve its dispersion stability in water. Then, the high thermal stability ZrO2 nanoparticles were immobilized in situ on the LDH/PDA surface to improve the strength and temperature resistance of the char layer by a hydrothermal strategy. The fire protection performance of [email protected]@ZrO2 (LPZ) modified intumescent fire retardant (IFR) coatings was performed by large plate method, thermogravimetric analysis (TGA) and furnace experiments. From the results, the IFR coating loaded with 2.5% LPZ exhibited the lowest backside temperature and the highest heat insulation, which reached 177.9 °C and 64.42, respectively. Besides, the coating exhibited the greatest expansion height (23.65 mm) and expansion rate (18.92), which is significantly higher than that of other coatings. Moreover, the maximum thermal degradation temperature (Tmax) and residual char of LPZ2.5%/EP were significantly higher than other samples. Further, the LPZ2.5%/EP based sample indicated the lowest smoke density rating (SDR) due to its excellent smoke suppression performance. The residual carbon analysis showed that ZrO2 nanoparticles and LDH nanosheets remained in the char layer during the combustion process, which is beneficial to increase the strength of the char layer and its barrier effect on heat and oxygen.

Mussel inspired polydopamine@KH560-linked hexagonal boron nitride and CNTs nanoflame retardants improve fire performance of composite coatings

Herein, the excellent properties of one dimension (1D) and two dimension (2D) nanoparticles were fully combined to enhance the thermal stability and flame retardancy of waterborne epoxy intumescent fire retardant (IFR) coatings. Specifically, layered hexagonal boron nitride (h-BN) nanosheet-linked acidified carbon nanotubes (CNTs) hybrids (BP@Si/CNTs) were prepared using polydopamine (PDA) and γ-(2,3-epoxypropoxy)propytrimethoxysilane (KH560) as bridging agents. The results of the fire test, furnace test and thermogravimetric analysis indicated that the incorporation of 2 wt% of BP@Si/CNTs hybrids in the IFR coating significantly improved the thermal stability and flame retardancy of the char layer. The backside temperature of the BP@Si/CNTs2.0%/EP sample decreased by 89.3 °C, the expansion rate increased by 11.53, and the residual char increased by 11.05 wt% compared to the control EP. The potential flame retardant mechanism was investigated by residual char analysis. The mechanism investigations indicated that the improved fire resistance of the composite coatings is attributed to the enhancement of the char layer by the physical barrier effect of the h-BN nanosheets and the "skeletal framework" effect of the CNTs during the combustion process.

The application efficiency of intumescent coatings for power cables of safety systems of nuclear power plants under fire conditions

Introduction. The reliable operation of safety systems, that allows for the failure of no more than one safety system component, entails the safe shutdown and cool-down of an NPP reactor in the event of fire. However, the co-authors have not assessed the loss of performance by an insulating material, treated by intumescent compositions and used in the power cables of the above safety systems exposed to the simultaneous effect of various modes of fire and current loads.Goals and objectives. The purpose of the article is the theoretical assessment of the application efficiency of intumescent fire-retardant coatings in power cables used in the safety systems of nuclear power plants having water-cooled and water-moderated reactors under fire conditions. To achieve this goal, the temperature of the outer surface of the insulation and the intumescent fire-retardant coating was analyzed depending on the mode of fire. Theoretical foundations. A non-stationary one-dimensional heat transfer equation is solved to identify the temperature distribution inside the multilayered insulation and the fire-protection layer of a conductive core.Results and their discussion. The co-authors have identified dependences between the temperature of the outer surface of the insulation and the fire retarding composition of the three-core cable VVGng (A)-LS 3x2.5-0.66, on the one hand, and the temperature of the indoor gas environment for three standard modes of fire and one real fire mode. It is found that before the initiation of the process of destruction of the insulation material, the intumescence of the fire-retardant coating occurs only in case of a hydrocarbon fire. Under real fire conditions, the maximal insulation melting time before the initiation of intumescence of the fire-retardant coating at the minimal temperature of intumescence is 4.75 minutes, while the maximal time period from the initiation of destruction of the insulation material to the moment of the insulation melting is 6.0 minutes.Conclusions. An experimental or theoretical substantiation of parameters of intumescent fire retardants, performed using standard modes of fire, has proven the potential loss of operational properties by insulating materials of power cables, used in the safety systems of nuclear power plants, in case of a real fire. Therefore, it is necessary to establish a scientific rationale for the efficient use of fire retardants in the above cables with regard for the conditions of a real fire.