scholarly journals INVESTIGATION INTO THE INFLUENCE OF FLAME RETARDANT ADDITIVES ON SOME FIRE PROPERTIES OF POLYESTER MATERIALS APPLYING SMALL-SCALE TESTING TECHNIQUES

2013 ◽  
Vol 19 (4) ◽  
pp. 561-572 ◽  
Author(s):  
Marzena Półka ◽  
Jerzy Gałaj ◽  
Zbignev Karpovič
Keyword(s):  
Flame Retardant ◽  
Ignition Temperature ◽  
Flame Retardants ◽  
Fire Hazard ◽  
Combustion Products ◽  
Small Scale ◽  
Local Reduction ◽  
Testing Techniques ◽  
Fire Properties ◽  
The Impact

In order to investigate the impact of some inorganic additive flame retardants on the selected fire properties of the materials based on polyester resin Polimal 1033 APy, small-scale fire testing techniques have been used. Seven samples have been studied: unmodified PES, PES modified with MoO3 (7, 14 and 21 wt%) and PES modified with Sb2O3 (7, 14 and 21 wt%). The following flammable properties of materials have been determined: the heat of combustion (HOC), the ignition temperature of volatile thermal decomposition products (Tig), self-ignition temperature and oxygen index. A cone calorimeter method has been used for determining heat release rate (HRR), mass loss, specific extinction area (SEA) and other combustion parameters. The toxicological analysis of combustion products has been conducted. Based on the obtained results, the following conclusions have been made: (1) MoO3 and Sb2O3 added to the studied material change its flammable properties and fire parameters. It can be indicated by higher HOC, higher Tig and self-ignition temperature, as well as by lower HRR and SEA. Modified materials become safer in terms of fire hazard. (2) A significant reduction in HRRmax of approx. 40% in the content of 7 wt% has been observed. The lowest HRRmaxof approximately 300 kW/m2 and 450 kW/m2 have been obtained for 21 wt% in a range of 200–600 s at 30 kW/m2 and 100–400 s at 50 kW/m2 respectively. Except for a sample containing 7 wt% of Sb2O3, a clear local reduction in HRR (from 50 to 150 kW/m2), in case of all modified samples has been noticed. (3) Sb2O3 has a greater impact on the thermostability of the studied materials compared to MoO3 in all cases of heat flux density and additive concentrations. The effectiveness of Sb2O3, as a flame retardant is the most evident at 21 wt%.

Materials for Safety and Security

2020 ◽  
pp. 288-320
Author(s):  
Jozef Martinka ◽  
Janka Dibdiakova
Keyword(s):  
Hydrogen Cyanide ◽  
Ignition Temperature ◽  
Fire Risk ◽  
Combustion Products ◽  
Security Engineering ◽  
Insulating Materials ◽  
Properties Of Materials ◽  
Materials Used ◽  
Carbon Monoxide Yield ◽  
The Impact

This chapter deals with materials used in safety and security engineering. The most commonly used materials in this field include shielding materials, materials for protective suits, electrically insulating materials and materials for fire protection. The first part of the chapter describes the properties of materials used in the above applications. The second part of the chapter focuses on characteristics of materials that accurately describe their fire risk. The fire risk of a material is quantified by its resistance to ignition (determined generally by critical heat flux and ignition temperature) and by the impact of the fire on the environment. The impact of fire is usually determined by the heat release rate, toxicity of combustion products (primarily determined by carbon monoxide yield and for materials that contain nitrogen, also through the hydrogen cyanide yield) and the decrease of visibility in the area (depending on the geometry of the area and the smoke production rate).

scholarly journals Effects of a Phosphorus Flame Retardant System on the Mechanical and Fire Behavior of Microcellular ABS

Polymers ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 30 ◽  
Author(s):  
Vera Realinho ◽  
David Arencón ◽  
Marcelo Antunes ◽  
José Velasco
Keyword(s):  
Flame Retardant ◽  
Impact Energy ◽  
Weight Reduction ◽  
Flame Retardants ◽  
Mechanical Performance ◽  
Fire Behavior ◽  
Acrylonitrile Butadiene Styrene ◽  
Injection Molding Process ◽  
Molding Process ◽  
The Impact

The present work deals with the study of phosphorus flame retardant microcellular acrylonitrile–butadiene–styrene (ABS) parts and the effects of weight reduction on the fire and mechanical performance. Phosphorus-based flame retardant additives (PFR), aluminum diethylphosphinate and ammonium polyphosphate, were used as a more environmentally friendly alternative to halogenated flame retardants. A 25 wt % of such PFR system was added to the polymer using a co-rotating twin-screw extruder. Subsequently, microcellular parts with 10, 15, and 20% of nominal weight reduction were prepared using a MuCell® injection-molding process. The results indicate that the presence of PFR particles increased the storage modulus and decreased the impact energy determined by means of dynamic-mechanical-thermal analysis and falling weight impact tests respectively. Nevertheless, the reduction of impact energy was found to be lower in ABS/PFR samples than in neat ABS with increasing weight reduction. This effect was attributed to the lower cell sizes and higher cell densities of the microcellular core of ABS/PFR parts. All ABS/PFR foams showed a self-extinguishing behavior under UL-94 burning vertical tests, independently of the weight reduction. Gradual decreases of the second peak of heat release rate and time of combustion with similar intumescent effect were observed with increasing weight reduction under cone calorimeter tests.

scholarly journals Vertical distribution of aerosols over the Maritime Continent during El Nino

2017 ◽  
Author(s):  
Jason Blake Cohen ◽  
Daniel Hui Loong Ng ◽  
Alan Wei Lun Lim ◽  
Xin Rong Chua
Keyword(s):  
Vertical Distribution ◽  
El Niño ◽  
Radiative Forcing ◽  
El Nino ◽  
Small Scale ◽  
Fire Plume ◽  
Radiative Power ◽  
Fire Properties ◽  
The Impact ◽  
Fire Radiative Power

Abstract. The vertical distribution of aerosols over Southeast Asia, a critical factor of aerosol lifetime, and impact on radiative forcing and precipitation, is examined for the 2006 post El-Nino fire burning season. Additionally, through analysis of measurements and modeling, we have reconfirmed the hypothesis that fire radiative power is underestimated. Our results are significantly different from what others are using. The horizontally constrained Maritime Continent’s fire plume median height, using the maximum variance of satellite observed Aerosol Optical Depth as the spatial and temporal constraint, is found to be 2.17 ± 1.53 km during the 2006 El Nino season. This is 0.96 km higher than random sampling and all other past studies, with 62 % of particles in the free troposphere. The impact is that the aerosol lifetime will be significantly longer, and that the aerosols will disperse in a direction different from if they were in the boundary layer. Application of a simple plume rise model using measurements of fire properties underestimates the median plume height by 0.34 km and more in the bottom-half of the plume. The center of the plume can be reproduced when fire radiative power is increased by 20 % (range from 0 % to 100 %). However, to reduce the biases found, improvements are required in terms of measurements of fire properties when cloud covered, representation of small scale convection, and inclusion of aerosol direct and semi-direct effects. The results provide the unique aerosol signature of fire under El-Nino conditions.

The effect of fire protection means on the intensity of heating and features of charring of wooden structures

2021 ◽  
Vol 94 ◽  
pp. 50-64
Author(s):  
I. O. Fedotov ◽  
◽  
A. B. Sivenkov ◽  
Keyword(s):  
Flame Retardant ◽  
Fire Resistance ◽  
Fire Protection ◽  
Flame Retardants ◽  
Large Scale ◽  
Fire Hazard ◽  
Experimental Studies ◽  
Systematic Research ◽  
Muffle Furnace ◽  
Wooden Structures

Introduction. Over the past decades, the sphere of wooden house construction has been undergoing revolutionary changes in relation to the development of large-scale construction using wood-based structures. In this regard, one of the first places is the direction associated with ensuring the fire-safe use of such structures in the construction of buildings and structures of various functional purposes. An important sector of this direction is various types and methods of fire protection for wood, materials and structures based on it. The lack of systematic research on these issues hinders the development of effective technical solutions for fire protection of wooden structures. Goals and objectives. Identification of priority areas for research in the field of fire protection of wood, materials and structures based on it. Development of effective flame retardants that can have an impact on reducing fire danger and increasing the fire resistance of wooden structures. Determination of the influence of various flame retardants on the intensity of the process of heating and charring of elements of wooden structures in conditions of fire exposure (fire). Methods. A standard muffle furnace of the SNOL type was used as a test installation with the possibility of one-sided radiation thermal effect on the sample surface and a uniform temperature increase in the furnace up to 1200 С. The muffle furnace was upgraded taking into account the horizontal fixing of the sample on the outer panel of the furnace. To measure the temperature by the thickness of the sample, a set of thermoelectric converters of type K (chromel-kopel) with a junction diameter of 0,8 mm was used. Results and their discussion. Based on the results of theoretical and experimental studies, the main directions of research on the possibility of using various methods and types of fire protection to achieve the required fire hazard characteristics and fire resistance of wooden structures were determined. During the study, the analysis of such characteristics of charring as the rate of charring, the thickness of the charred layer was carried out. Conclusion. The research results show the possibility of certain classes of flame retardants, intumescent and heat-protective materials not only to influence the intensity of the process of charring wood, but also to affect the properties and structure of the charred layer, as well as the intensity of heating of the inner layers of wooden structures. Key words: fire resistance, fire resistance limit, fire hazard, charring, heating intensity, flame retardant efficiency, wood, wooden structures, flame retardant coatings, flame retardants.

Thermal Radiation Modelling in Tunnel Fires

2011 ◽  
Vol 3 (3) ◽  
pp. 327-353 ◽  
Author(s):  
Paolo Ciambelli ◽  
Maria Grazia Meo ◽  
Paola Russo ◽  
Salvatore Vaccaro
Keyword(s):  
Fire Hazard ◽  
Hazard Analysis ◽  
Combustion Products ◽  
Small Scale ◽  
Transfer Model ◽  
Cfd Modelling ◽  
Tunnel Fires ◽  
Tunnel Fire ◽  
Radiation Modelling ◽  
In Fire

AbstractModelling based on Computational Fluid Dynamics (CFD) is by now effectively used in fire research and hazard analysis. Depending on the scenario, radiative heat transfer can play a very important role in enclosure combustion events such as tunnel fires. In this work, the importance of radiation and the effect of the use of different approaches to account for it were assessed. Firstly, small-scale tunnel fire simulations were performed and the results compared with experimental data, then realistic full-scale scenarios were simulated. The results show up the capability of CFD modelling to reproduce with good approximation tunnel fires. Radiation proved to be noteworthy mainly when the scale of the fire is relatively large. Among the various approaches employed to simulate radiation, the use of the Discrete Transfer model gave the most accurate results, mainly when the absorption-emission characteristics of the combustion products were taken into account. Finally, the suitability of the use of CFD in quantitative Fire Hazard Analysis is discussed.

The impact of sulfur oxidation level on flame retardancy

2018 ◽  
Vol 36 (6) ◽  
pp. 518-534 ◽  
Author(s):  
Bob A Howell ◽  
Yoseph G Daniel
Keyword(s):  
Flame Retardant ◽  
Flame Retardancy ◽  
Flame Retardants ◽  
Sulfur Oxidation ◽  
Diglycidyl Ether ◽  
Oxidation Level ◽  
The Impact

Compounds containing sulfur in various forms may be used as flame retardants or as adjuvants to promote the activity of other flame-retarding elements, most notably phosphorus. To gain a better understanding of the nature of the sulfur moiety in a flame retardant on performance, a series of phosphorus esters derived from isosorbide containing sulfur at various levels of oxygenation (sulfide, sulfoxide, sulfone) have been prepared and evaluated for flame-retardant impact in diglycidyl ether of bis-phenol A epoxy. In all cases, the presence of sulfur positively impacts flame retardancy. In general, the impact on flame retardancy increases as the level of oxygenation at sulfur increases (sulfone > sulfoxide > sulfide).

scholarly journals COMPARATIVE STUDY OF THE EFFECT OF FLAME RETARDANTS ON THE IGNITION TEMPERATURE OF EPOXY COMPOSITES

2021 ◽  
Vol 18 (2) ◽  
pp. 76-80
Author(s):  
Yu.A. Amelkovich ◽  
Keyword(s):  
Epoxy Resin ◽  
Ignition Temperature ◽  
Flame Retardants ◽  
Fire Hazard ◽  
Combustion Process ◽  
Control Sample ◽  
Polymeric Materials ◽  
Epoxy Composites ◽  
Magnesium Phosphate ◽  
Aluminum Trihydroxide

The disadvantage of polymeric materials, including epoxy resins, is their increased fire hazard. Reducing the flammability of polymeric materials is a serious problem that needs to be addressed. One of the ways to reduce the flammability of polymers is the introduction of special additives into the polymer matrix with flame retarding properties, which leads to a change in the nature of the processes occurring during the combustion of the polymer, or to blocking the combustion process with non-combustible or inhibiting substances. In this work, aluminum trihydroxide, melamine polyphosphate, and melamine poly(magnesium phosphate) were used as flame retardants to enhance the flame-resistant properties of epoxy resin. The filler loading in the epoxy composites was 10 wt. %. The experimental studies have been carried out to determine the ignition temperature of the produced epoxy composites. The data obtained were compared with the ignition temperature of a control sample of epoxy resin without filler. The results indicated that the incorporation of all the flame retardants studied resulted in an increase in the ignition temperature. The ignition temperature of the samples filled with melamine polyphosphate and melamine poly(magnesium phosphate) increased by 28 and 11 °C, respectively. However, the best result was obtained for a sample filled with aluminum trihydroxide: the ignition temperature of this sample was 40 °C higher than that of the unfilled epoxy resin.

Heat Release Performance of the Flame Retardant Rigid Polyurethane Insulation Foam

2013 ◽  
Vol 785-786 ◽  
pp. 131-137
Author(s):  
Ze Jiang Zhang ◽  
Li Jun Li ◽  
Feng Li ◽  
Jin He ◽  
Zi Qiong Gan
Keyword(s):  
Heat Release ◽  
Flame Retardant ◽  
Heat Release Rate ◽  
Release Rate ◽  
Ignition Temperature ◽  
Flame Retardants ◽  
Total Heat ◽  
Antimony Trioxide ◽  
Rigid Polyurethane Foam ◽  
Total Heat Release

Influence of different flame retardants on the heat release performance of the rigid polyurethane foam (RPF) was studied in this paper. It was found that adding antimony trioxide (ATT) in RPF, heat release rate of RPF was slightly reduced, total heat release was significantly decreased but peak of heat release temperature was decreased. Therefore, ATT was not an excellent flame retardant for RPF. When adding ammonium polyphosphate (APP) in RPF, total heat release of RPF was significantly decreased, ignition temperature was significantly improved and heat release rate was not changed. Melamine polyphosphate (MPOP) could quickly reduce total heat release of RPF so its flame retardant effect was the best. Nitrogen-based flame retardants could reduce peak of heat release rate of RPF. APP, MPOP and nitrogen-based flame retardants were all better flame retardants for RPF. Small amount of magnesium hydroxide (MH) could increase total heat release of RPF.

Brominated flame-retardant composition in firefighter bunker gear and its thermal performance analysis

2021 ◽  
pp. 073490412110012
Author(s):  
Vincent Mokoana ◽  
Joseph Asante ◽  
Jonathan Okonkwo
Keyword(s):  
Flame Retardant ◽  
Thermal Performance ◽  
Polybrominated Diphenyl Ethers ◽  
Flame Retardants ◽  
Brominated Flame Retardants ◽  
Heat Fluxes ◽  
Brominated Flame Retardant ◽  
X Ray ◽  
Diphenyl Ethers ◽  
The Impact

Firefighting bunker gear is manufactured from flame-retardant materials, which resist ignition and delay flame spread. However, concerns have been emerging on the potential harmful effects of some flame retardants (FRs) commonly used in flame-retarding materials, particularly the brominated flame retardants. This study investigated the presence of flame retardants in bunker gear, particularly polybrominated diphenyl ethers and their congeners in the garments, and evaluated their impact on thermal performance. X-ray fluorescence spectroscopy was used to ascertain the presence of bromine as a possible indicator for brominated flame retardants. X-ray fluorescence results indicated the presence of Br in all samples, ranging from 444 to 20,367 µg/g. Further analysis via gas chromatography–mass spectrometry was done on samples. Brominated flame retardants, particularly polybrominated diphenyl ethers and hexabromocyclododecane, were detected in all samples with concentrations ranging from 261.61 to 1001.77 µg/g and 0.01 to 0.07 µg/g, respectively. The cone calorimeter was used, with 50 and 75 kW/m2 heat fluxes, to investigate the impact of the brominated flame-retardant concentrations, if any, on thermal performance. New bunker garments, particularly those with lower Br and brominated flame-retardant concentrations, were observed to have higher thermal performance.

Can Values of Honesty, Hard Work, Loyalty and Discipline Predict Entrepreneurial Orientation of Muslim Owner Managers?

2015 ◽  
Vol 3 (1) ◽  
pp. 31 ◽  
Author(s):  
Rohani Mohd ◽  
Badrul Hisham Kamaruddin ◽  
Khulida Kirana Yahya ◽  
Elias Sanidas
Keyword(s):  
Entrepreneurial Orientation ◽  
Two Dimensions ◽  
Hard Work ◽  
Small Scale ◽  
Sampling Frame ◽  
Policy Makers ◽  
Learning Institutions ◽  
Innovative Orientation ◽  
The Impact ◽  
True Values

The purpose of the present study is twofold: first, to investigate the true values of Muslim owner managers; second, to examine the impact of these values on entrepreneurial orientations of Muslim small-scale entrepreneurs. 850 Muslim owner managers were selected randomly using the sampling frame provided by MajlisAmanah Rakyat Malaysia (MARA). 162 completed questionnaires were collected and analyzed. For this paper only two dimensions of entrepreneurial orientations were analyzed: proactive orientation and innovative orientation. Interestingly, the findings revealed that Muslim businessmen/women are honest, loyal, disciplined and hard working. Loyalty and honesty are positively related to proactive orientation, while discipline and hard-work are positively related to innovative orientation. The findings provide implications for existing relevant theories, policy makers, practitioners and learning institutions. 

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