Fire-retardant Materials Research Articles

Parameter estimation approach to the thermal characterization of intumescent fire retardant paints

Intumescent paints are widely used as passive fire retardant materials in the building sector. They swell on heating to form a highly insulating char, protecting steel members. Intumescent coatings for use in buildings are typically certified according to the standard cellulosic fire resistance test. This test is expensive, often non-representative of realistic fire conditions, and not enough versatile to gather detailed performance information on the response of reactive coatings. A promising approach, that could offer a helpful tool to the engineering community involved in fire safety, is found in the modelling of the behaviour of the intumescent coating. Under this approach, the knowledge of the equivalent thermal conductivity of the intumescent material is a fundamental issue, since it represents the main parameter that allows predicting the thermal protecting capability of the layer. The purpose of this paper is to optimize an estimation procedure intended to the restoration of the equivalent thermal conductivity of intumescent layers. The thermal stress is activated by the action of a cone calorimetric apparatus, while the estimation procedure is based on the inverse heat conduction problem approach under steady state assumption, where the temperature values measured at some locations inside the layer during the expansion process are used as input known data. This procedure was successfully applied to steel samples protected with an intumescent paint; the estimated equivalent thermal conductivity of the layer results to temperature dependent while the initial thickness of the paint does not seem to have a great effect.

Commingled nanocomposites of LDPE/PP/Nylon 6/EPDM reinforced with MWCNT and Kenaf Fiber with enhanced mechanical, thermal and flammability characteristics

Abstract Multicomponent commingled composites comprised of LDPE, PP, Nylon 6 and EPDM have been prepared using a mixture of two epoxy functionalized polyolefins as compatibilizers to enhance interfacial interactions. Kenaf fiber has also been added for reinforcement along with Multiwalled carbon nanotube (MWCNT). The mechanical and thermal properties for the nancomposites have been determined and assessed using predictive theories. The flammability characteristics for the nanocomposites were also assessed. The presence of MWCNT enhanced mechanical properties and also promoted char formation along with improved fire retardancy of the nanocomposites. These composites have potential for application as high performance fire retardant materials by recycling mixed plastic waste.

Study on the Preparation Road Performance of New Inorganic Fire-Retardant-Modified Asphalt

To develop a purely inorganic fire-retardant-modified asphalt, the authors selected highly fire-retardant materials that have low-carbon content, non-polluting properties, and are inexpensive as fire retarder of asphalt. The optimal preparation technique for inorganic fire-retardant-modified asphalt is determined on the basis of three indexes of modified asphalts. First, limiting oxygen index and smoke density tests are conducted to investigate the influencing regularity of the dosage and type of inorganic fire retarder on fire and smoke retardant properties of inorganic fire-retardant-modified asphalt. Second, the TG test is used to explore the fire-retardant mechanism of inorganic fire-retardant-modified asphalt. Third, by testing the viscosity, anti-aging property, and adhesion of the inorganic fire-retardant-modified asphalt, the influencing regularity of inorganic fire-retardant dosage on the road performance of the modified asphalt is studied. Finally, the economic benefits of the inorganic fire-retardant-modified asphalt are analyzed. Results showed the following: (1) the inorganic fire retarder has good fire and smoke retardant properties and can meet the requirements of the corresponding national specifications; (2) the fire-retardant property of the inorganic fire-retardant-modified asphalt can be increased significantly by increasing the dosage of the fire retarder, and the smoke retarder can improve the fire-retardant property with its functions (these properties overcome the contradictory shortcomings between fire and smoke retardant properties); (3) the effect of the fire retardant mainly depends on the decomposition and release of water from the inorganic fire retarders, and the absorption effect of the layered metal oxide; (4) with the increasing dosage of the inorganic fire retarder, the degree of penetration and ductility of the inorganic fire-retardant-modified asphalt decreases, the softening point and viscosity increase, and the penetration ratio and viscosity become larger; (5) the addition of the inorganic fire retarder does not affect the adhesion of SBS-modified asphalt. The inorganic fire-retarder has excellent economic benefits and is suitable for promotion and application in fire-retardant asphalt mixtures for pavements.

Review: Progress in Research on near Infrared Spectroscopy for Fire Product Quality Rapid Detection in China

This article describes a present fire product certification system and some of the problems in supervision and management. The crucial components of extinguishing agents and fire-retardant materials are still unable to be detected rapidly on-site using the GA588 rules for field inspection and judgement of fire products. This article introduces the progress in research on near infrared (NIR) spectroscopy technology for active ingredients, moisture detection, species identification and brand identification of dry powder extinguishing agents, fireproof coatings and heptafluoropropane. It proves that NIR technology can rapidly, accurately and non-destructively measure dry powder extinguishing agents, fireproof coatings and heptafluoropropane. The construction of a rapid detection management system for fire extinguishing agents and fire-retardant materials is put forward.

Synthesis and properties of novel high thermally stable polyimide-chrysotile composites as fire retardant materials

Abstract Novel high thermally stable polyimide-chrysotile (PI-Chr) composites were synthesized. Firstly, Chrysotile (Chr) was modified with 3-aminopropyltriethoxysilane (APS). Poly(amic acid) solution was synthesized from pyromellitic dianhydride (PMDA) and 4,4′-diaminodiphenyl ether. Then, PI-Chr composites were prepared from poly(amic acid) solution and different ratios of modified Chr. Prepared PI-Chr composites were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray spectroscopy and thermal analysis techniques. Thermal analysis results showed that the PI-Chr composites have higher decomposition temperatures in comparison with the pure PIs. A 10% weight loss belonging to PI-Chr composites was observed between 489°C and 536°C in air atmosphere, but this value was 468°C in air for pure PIs. The glass transition temperatures (Tg s) of the PI-Chr composites were 373°C–384°C, depending upon the amount of the Chr. PI-Chr composites exhibited improved thermal stability. The activation energies (E a s) of the thermal degradation reaction were calculated using the Kissinger method for pure PI and composites. The E a s of the PI-Chr composites were found to be 77 and ∼117 kJ/mol. The fire retardant properties of Chr in the PI matrix were also tested by the total heat release test. The introduction of Chr in the composites leads to a slight increase in fire retardant properties thermal stability.

Correlations of limiting oxygen index with structural polyphosphoester features by QSPR approaches

Fire retardant materials diminish the hazard to life from fire. Polyphosphonates and polyphosphates display good flame retardancy and attractive plasticizing properties, being an important class of organophosphorus based polymer additives. Properties of previously synthesized polyphosphoesters are presented here, being simulated as monomers. In this quantitative structure–property relationship work, the flammability was expressed by limiting oxygen index (LOI) values, which were determined experimentally. Two types of chiral structures were found by molecular mechanics calculations using the MMFF94s force field for half of the monomers, consequently, two datasets were built. Structural parameters were calculated for the minimum energy structures and were related to the LOI values by multiple linear regression (MLR), artificial neural networks (ANNs), and support vector machines (SVMs). MLR calculations were combined with a genetic algorithm for variable selection. Stable and predictive MLR models in terms of 2D autocorrelation parameters weighed by atomic polarizabilities and of 3D-Morse descriptors were obtained. Somewhat inferior fits were found in the nonlinear modeling by ANNs and SVMs with the same set of descriptors. Monomers including R chiral structures gave more stable and predictive models compared to the S isomers in all approaches. Monomer geometry influences the flame retardancy, being favorable for R isomers.

Analysis of Application of Molecular Sieve on the Woody Fire-Retardant Research

In the past decade, molecular sieves are applied to the flame retardant research areas. This article introduces the types and functional features of molecular sieve, especially the properties of mesoporous molecular sieve, the function of porous channel system, the method of controlling the aperture and the way of functional modification. On the basis of induction and analysis of molecular sieve in fire-retardant research, I have made three points: (1) Molecular is a good kind of fire-retardant synergist; (2) A little molecular added is enable to improve the ability of fire-retardant materials; (3)Bringing the molecular sieve into woody material is in the trend of smog-retardant, low-poisonous, environment-friendly.

The correlation between carbon monoxide and hydrogen cyanide in fire effluents of flame retarded polymers

This study considers the demonstrated correlation between carbon monoxide and hydrogen cyanide in the special case of fire retarded materials. It shows that the combination of aluminium phosphinate and melamine polyphosphate causes a much smaller increase in the carbon monoxide (CO) and hydrogen cyanide (HCN) yields than the combination of brominated polystyrene and antimony oxide, although both fire retardants inhibit combustion reactions in the gas phase. The formation and destruction mechanisms of CO and HCN are considered. It is shown that both toxicants form early in the flame, and that the OH radical is critical for the destruction of both CO and HCN. Crucially, in the context of the flame inhibition mechanism, this suggests that the phosphorus system reduces the H and O radical concentrations without a corresponding decrease in the OH radical concentration, thus it is an effective gas phase flame retardant which only causes a small increase in the toxic product yields. Conversely, the bromine system reduces the H, O and OH concentrations, and thus increases the fire toxicity, by inhibiting decomposition of CO and HCN. Moreover, while the phosphorus flame retardant is effective as an ignition suppressant at low temperatures, this effect ―switches off‖ at higher flame temperatures, minimising the potential increase in fire toxicity, once the fire develops.

Modeling the Effect of Thermophysical Properties on Pyrolysis of Intumescent Fire-retardant Materials

Thermophysical properties of intumescent fire-retardant (IFR) materials are important input parameters to simulate the pyrolysis process of IFR materials in fire scenarios. In this article, the effects of the thermophysical properties on pyrolysis of IFR materials are simulated based on a pyrolysis model of IFR materials. The selected thermophysical properties here are the specific heat capacity of the virgin material, thermal conductivity of the virgin material and char layer, heat of decomposition, density of virgin material, intumescent temperature, and surface emissivity of virgin material and char layer. Simulated mass loss rates (MLR) for the IFR materials at an incident heat flux of 50 kW/m2 are investigated for the varied thermophysical parameter values. The results show that changes in these property values can affect the pyrolysis behavior of materials profoundly. Comparison with experimental results indicates that the simulations of MLR are in reasonably good agreement with the experiments.

A Study into the Standardization of Using Fire Detectors in Rail Vehicles for China

Abstract Apart from using fire retardant materials, fire detection and alarm system could be another effective way to improve overall fire safety level of rail vehicles. And this has been suggested by the latest European Standard. However, in China, such application has not been well studied or standardized yet. Therefore, in this paper, by a study into major foreign standards and relating literatures, the author summarizes some major considerations for standardization of using fire detector in rail vehicles. And some suggestions as well as future work are proposed for establishing such standard in China.

Study on prevention of spread of vertical fire along finishing materials for external wall of high-rise buildings

Although there are laws in the Korea Building Act relating to exterior finishing materials, fireproof structures and fire-stop of curtain wall structures, the standards relating to and test methods on securing detailed fire safety functions for exterior materials of all buildings including high-rise buildings have not been prepared. This is due to the fact that test methods and standards to quantitatively evaluate the vertical fire spread of the exterior material of buildings do not exist. In addition, while semi non-combustible materials or non-combustible materials are required to be used to prevent fire spread in buildings which exceed 30-stories, it is necessary to review the standards and regulations in cases where fire blocking systems, capable of preventing the vertical fire spread within the curtain wall, are installed to consider permitting the utilization of fire retardant material following an assessment of the construction characteristics of high-rise buildings. The functional evaluation standards and test methods on the vertical fire spread introduced in this study will be a more effective method for performing evaluations to prevent fire spread compared to the currently utilized method of performing small scale tests.

일반재와 난연재 알루미늄복합패널의 수직화재 성상분석을 위한 실대형시험(ISO 13785-2)에 관한 연구

본 연구에서는 건축 외장재로 많이 사용되고 있는 알루미늄복합패널의 일반재와 난연재에 대한 실제 화재에서의 화재성상을 분석하기 위하여 실대형 시험(ISO 13785-2)을 수행하였다. 시험결과, 일반재인 경우 최고 온도가 210초에 <TEX>$1,021^{\circ}C$</TEX>가 측정되었으며, 난연재는 약 1,200초에 <TEX>$1,190^{\circ}C$</TEX>가 측정되었다. 화재성상은 알루미늄복합패널 중 난연재의 경우 착화가 더디게 진행되었으며, 일반재의 알루미늄복합패널은 연소착화와 동시에 화재가 빠르게 확산되었다. 일반재와 난연재의 알루미늄복합패널은 연소착화하는데는 분명한 차이를 보였지만, 일단 착화된 이후에는 수직화염의 확산의 연소형태는 일반재나 난연재 모두 빠르게 수직확산되는 비슷한 양상을 보였다. 이에 본 연구결과, 알루미늄복합패널에 대한 화재위험성을 줄이기 위해서는 난연재 사용을 적극적으로 유도하도록 하며, 또한, 일단 착화 후에는 이를 진압할 외장재 전용 소화설비의 적용이 시급함을 알 수 있었다. In this sturdy, large experimental (ISO 13785-2) was performed to analyze the building materials used in fire retardant materials for aluminum composite panel and in general properties. As a results, maximum temperature in the case of the general materials was measured in 210 seconds <TEX>$1,021^{\circ}C$</TEX>, the retardant materials was measured in 1,200 seconds early <TEX>$1,190^{\circ}C$</TEX>. The retardant material of aluminum composite panel, Fire behavior if the ignition is slow and the general materials in aluminum composite panel, fire ignition and combustion at the same time was growing rapidly. The general materials and flame-retardant material of aluminum composite panel was an obvious difference to the combustion ignition but after ignition combustion mode showed a similar pattern of the rapidly vertical spread of flame. The results of this study, in order to reduce the risk of aluminum composite panels for fire and the retardant materials used for ignition the slow should be actively encouraging. Also after the ignition, there is an urgent need to put out a fire in exterior materials for extinguishing facilities.

Influence of thermophysical properties on burning behavior of intumescent fire-retardant materials

Thermophysical properties of intumescent fire-retardant (IFR) materials are important parameters as input data in modeling the combustion process of IFR materials in a fire. In this paper, the influences of several thermophysical properties on burning behavior of IFR materials are simulated based on a combustion model of IFR materials. Thermophysical properties selected here are thermal conductivity of virgin material and char layer, specific heat capacity of virgin material, density of virgin material, surface emissivity of virgin material and char layer, heat of decomposition, heat of combustion, and intumescent temperature. Predicted heat release rates curves for the IFR material at an incident heat flux of 50 kW m−2 are shown for the varied thermophysical parameters’ values. The results show that these varied parameter values can affect the burning behavior of materials remarkably. A comparison with experimental results demonstrates that the predictions of heat release rates are in reasonably good agreement with the experiment.

The Quantitative Analysis of the Thermal Radiation Protective Effect in the Fire-Retardant Insulation Materials of the Fire Protective Clothing

The fire protective clothing is essential protective equipment in fire-fighting operations for the firefighters, which can effectively reduce the damage of high temperature and radiation to the firefighters in the fire. In the actual fire-fighting and rescue, mastering the specific thermal protective effect of the fire protective clothing is necessary in order to accurately grasp the security extinguishing distance. Firstly, this paper presents an overview of the development and performance requirements of the fire-retardant insulation materials for the fire protective clothing, and performance evaluation standards are also introduced. And then take a large crude oil reserves depot for example, and set the pool fire scene inside the tank, which builds the risk analysis model of pool fire. Not considering the impact of the wind speed, the flame height of a single tank in the pool fire is 76.2m, and the total thermal radiation flux is 1.4 × 106kw. The threshold is set at the standard that the firemen directly affected by the thermal radiation feels the pain above 20s, and the safe diSuperscript textstance of extinguishing the fire for the firefighters is 167m without the protective clothing; the safe distance of extinguishing the fire for the firefighters is 78.4m under the protection of the clothing.

Research on the Flame-Retardant Property of Continuous Basalt Fiber Based on Basic Properties of Advanced Composite Materials

In this paper, Continuous Basalt Fiber (CBF) was used as the raw materials, and then woven by the Digital sample looms. Experimental results show that CBF has a very high limiting oxygen index, even if which more than 69%, was much higher than 27% of the indicators of the non-combustible fiber. In the Vertical Burning Test, there was no burning, smoldering, continued burning phenomenon, which can be clearly seen, and the mechanical properties can remain stability in the before-and-after-test. The CBF, would be bound to play a significant role in future of fire-retardant materials and high-temperature composite materials, exhibited excellent flame resistance and heat resistance.

Fire Performance of the Wood Treated with Inorganic Fire Retardants

To prepare the eco-friendly fire retardant wood, Japanese red pine (Pinus densiflora), Hemlock (Tsuga heterophylla), and Radiata pine (Pinus radiata) were treated with inorganic chemicals, such as sodium silicate, boric acid, ammonium phosphate, and ammonium borate. Different combination and concentration of those chemicals were impregnated by vacuum/pressure treatment methods. The electron-beam treatment was used to increase the chemical penetration into the wood. The fire performance of the fire retardant treated wood was investigated. The penetration of chemicals into the wood was enhanced after electron beam treatment. Ignition time of the treated wood was the most effectively retarded by sodium silicate, ammonium phosphate, and ammonium borate. The most effective chemical combination was found at 50% sodium silicate and 3% ammonium borate, which satisfied flammability criteria for a fire retardant material in the KS F ISO 5660-1 standards.

ATR investigation of the mass residue from the pyrolysis of fire retarded lignocellulosic materials

The objective of this study was firstly to assess the magnitude of the chemical effect of DAP as fire retardant on the lignocellulosic material Olea europaea employing TGA. Therefore pyrolysis experiments of O. europaea before and after treatment with DAP 15% have been conducted using a TGA analyzer under nitrogen (N2) flow. Secondly the objective was to investigate the effect of DAP at different temperatures based on the solid mass residue using infrared spectroscopy. Thus, mass residues obtained at 180, 260, 320, 400, 500 and 600°C respectively from TGA were examined by FTIR-ATR. Using the TGA curves of DAP and O. europaea (pristine) respectively, a calculated curve has arisen (0.85×TG curveO.europaea25–500°C+0.15×TG curveDAP25–500°C). A comparison between this curve and the measured of the sample O. europaea+DAP 15%, showed that since they do not coincide, there is a chemical synergy between O. europaea and DAP. FTIR-ATR was employed to investigate the decomposition path of hemicelluloses, cellulose and lignin by detecting the characteristic peaks of the pyrolysis mass residues at different temperatures. Above 25°C, several characteristic peaks gradually do not reappear. On the contrary, when DAP is present these characteristic peaks continue to appear shifting to higher temperatures implying its chemical effect on the lignocellulosic materials. This observation is verified by the shifting of the DTG curve of O. europaea treated with DAP towards lower temperatures and less pronounced peaks at the DTG curves. The combination of TGA and FTIR-ATR is a useful tool for the investigation of a fire retardant's effect on the thermal decomposition of lignocellulosic materials.

Improved Flame Retardancy and Mechanical Properties of Composite Material S-NiMgAl-Y/EVA

The stearate surface modified LDHs S-NiMgAl-Y was rapidly synthesized based on the coprecipitation coupled with the microwave hydrothermal treatment. The cone calorimeter data confirmed that composite S-NiMgAl-Y/EVA has the good functions of both the flame retardancy and smoke/toxic gas suppression. The tensile strength of S-NiMgAl-Y/EVA was increased to the maximum value of 25.6 MPa when the addition of 10 wt.% S-NiMgAl-Y to EVA. This value is markedly larger than that of the pristine EVA equaling 20.8 MPa. The composite material developed in the present work greatly contributes to the processing and application of the fire retardant material.

Experimental Study on Thermal Diffusivity of Intumescent Fire-Retardant Materials

Thermal properties of intumescent fire-retardant materials are important parameters as input data in modeling combustion behavior of these materials in fire. However, Data regarding thermal properties especially thermal diffusivity of these composites are sparse. In this paper, intumescent fire-retardant polypropylene (IFR-PP) and char formed after the combustion of IFR-PP materials by the cone calorimeter at heat flux level of 50 kW/m2 are studied to obtain the thermal diffusivity data of them. Study results show the value of thermal diffusivity for IFR-PP tends to decrease when the temperature increase especially in higher temperatures. Thermal diffusivity of char formed after the combustion of IFR-PP material decreases gradually with the rise of temperature. Thermal diffusivity value measured at room temperature could not be used as input parameters in a combustion model when it is established to simulate the burning behavior of IFR-PP composites in fire.

난연소재와 일반소재 알루미늄복합패널의 연소특성 비교에 관한 실험적 연구

본 연구에서는 건축외장재로 많이 사용되고 있는 알루미늄복합패널의 일반재와 난연재에 대한 화재성능 비교분석에 관해 연구하였다. 실험방법은 중소형 실험장치 중 콘칼로리미터 실험과 SBI(Single Burning Item)을 적용하여 분석하였다. 그 결과 콘칼로리미터 실험에서 최대 열방출률이 일반 알루미늄복합패널은 <TEX>$1,293kW/m^2$</TEX>(<TEX>$75kW/m^2$</TEX>), 난연 알루미늄복합패널은 <TEX>$70kW/m^2$</TEX>(<TEX>$75kW/m^2$</TEX>)가 측정되었다. SBI 실험에서 화재확산지수가 일반 알루미늄복합패널은 약 743W/s이고 난연 알루미늄복합패널은 약 97 W/s의 값이 측정되었다. 이는 일반 알루미늄복합패널의 경우 건축물 내장재의 성능기준에서 난연기준에도 훨씬 못 미치고, 플래쉬 오버(Flash over) 발생 가능성을 나타내었다. 따라서 이러한 알루미늄복합패널의 화재 위험성을 평가하여 외장재로서 사용 시 갖춰야 할 조건에 대한 기준마련이 시급히 요구된다. In this research, aluminum composite panels of the general materials and fire retardant materials as building claddings make researches about fire performance comparison analysis. Test methods of the small and medium cone calorimeter experiments and SBI (Single Burning Item) experiments was applied to the determination. As a result, in the experiments peak heat release rate cone calorimeter the general aluminum composite panel <TEX>$1,293kW/m^2$</TEX> (<TEX>$75kW/m^2$</TEX>), flame-retardant aluminum composite panel <TEX>$70kW/m^2$</TEX> (<TEX>$75kW/m^2$</TEX>) was measured. In the SBI experiments fire growth rate the general fire aluminum composite panel is approximately 743 W/s and the flame-retardant aluminum composite panel is approximately 97 W/s of the value were measured. Thus, a standards enactment are urgently required in this case it is used as building claddings of the aluminum composite panel by fire risk assessment.