Fire Protection Properties Research Articles

Corrosion and Fire Protective Behavior of Advanced Phosphatic Geopolymeric Coating on Mild Steel Substrate

The research objectives of this study were to investigate and compare corrosion and fire protective properties of conventional and advanced phosphatic geopolymeric coating on mild steel substrate using spray coating technique For these studies two composition were developed using conventional geopolymerisation route by adding alkali activator solution to fly ash and six compositions were developed using advanced geopolymerisation process in which water was added to solid precursor powder obtained by together co-ginding of raw materials for a period of 8 h. Coated plates were tested for adhesion strength, water resistance, fire protection and corrosion resistance. Results indicated that coating developed from two passes with thickness 100 ± 15 μm showed better adhesion as compared to single pass and also proved to be promising corrosion protective coating material for mild steel substrate under sea water conditions. The developed material is able to withstand flame for more than 45 min and also no cracks were observed in coating by direct heating on liquefied petroleum gas flame. Thus developed phosphatic geopolymeric material is well suited for protecting the mild steel structures from fire and corrosion.

Establishment of heat­exchange process regularities at inflammation of reed samples

The conducted studies into the influence of induction period on reed inflammation have established the mechanisms of the process of heat transfer to material which makes it possible to influence this process. It was proved that these mechanisms consist in heating material to a critical temperature at which an intensive decomposition of the material occurs with release of a critical amount of combustible gases and their inflammation. This makes it possible to establish effect of fire protection and properties of roofing formulations on inhibition of the reed inflammation process. Experimental studies have confirmed that untreated reed inflames under thermal action in 58 seconds which is respectively equal to the induction period of material decomposition and flame spreads throughout the material surface which results in a complete combustion of material. Duration of the induction period extends to 587.45 s due to decomposition of flame retardants under thermal action with emission of non-combustible gases inhibiting material oxidation and significantly intensifying formation of a heat protective layer of coke on the reed surface. This leads to a growth of the coke layer thickness and inhibition of heat transfer from high temperature flame to the material. The study has made it possible to determine conditions of fire protection of reed by creating a barrier for thermal conductivity. In addition, when a flame-retardant protection coating is applied, the temperature effect manifests itself in reactions in the pre-flame region with formation of soot-like products on the surface of a natural combustible material. This gives grounds to assert that the mechanism of imparting fire protection properties to the reed by means of bloating formulations is feasible and that the proposed technological solutions have practical attractiveness. The latter, in particular, relate to determination of quantity of the polymeric component since the reed is characterized by hydrophobicity and the aqueous solution of the flame detergent flows off the surface. Thus, there are grounds to assert that the controlled fire protection of reed can be ensured through the use of a complex roofing formulation of a mixture of flame retardants and a natural polymer capable of forming a flame-retardant film on the material surface

New Method of Quality Control for Fire Protective Coatings

This research highlights testing measurements for quality control of fire protective coating on the all life cycle services, which is aimed to improve the processing technology of product coatings, the quality of building and energy saving. Short-time experiments in resistance to climate factors were carried out in order to check the possibility of dielectric method appliance for quality control of fire protective coating during service life, with further measurement of dielectric and fire protective properties. This work analyses the thermal decomposition and fire-protective properties, based on visual inspection of surface appearance for all protected constructions at all protected area and criteria of coating surface appearance with the requirements of normative documents for its appliance. Thin-layer fire protective coatings were chosen for the experiments to appraisal fire protection quality control of steel constructions. Experiments were carried out for frequencies 100, 120, 1000, 10000 and 100000 Hz at temperature 26°C and relative humidity 45% within a week daily, for 30 min with a break 1 min. Obtained data array were processed statistically in order to determine mean root square deviation and H confidence limits. Mean root square deviations were also calculated for the data obtained for 30 measurements within 24 hours.

АНАЛІЗ ВПЛИВУ ВХІДНИХ КОМПОНЕНТІВ НА ТЕПЛОФІЗИЧНІ ВЛАСТИВОСТІ ПОКРИТТЯ ПРИ ВОГНЕВОМУ ВПЛИВІ

Purpose. Development of fire protection composition and study of its properties: definition of fire protection group of the proposed coating. Methodology. In the course of the research, an analytical review of the main groups of fire retardants, which increase the fire resistance of wooden construction constructions, gave an assessment of their technical characteristics, as well as in accordance with DSTU B V.1.1-4-98 "Fire protection. Building constructions. Test methods for fire resistance. General requirements "defines the fire-protective properties of the developed fire protection coating. Findings. The authors developed a composition of flame retardant coating that forms on the surface, which "protects" a thin non-transparent layer that prevents inflammation and spread of flame on a wooden structure. The selection of composition of fire protection composition was carried out according to the scheme "compound - the additive that is flowing -the filler". The basis of the coating is liquid glass, because it has such positive characteristics as accessibility, due to the manifestation of liquid glass adhesive properties - the ability to spontaneous hardening with the formation of artificial silica. An increase in the content of fillers can increase the use interval of the composition to 900-9200С, and the maximum temperature at which provides the swelling of the coating 540-6800С. According to studies, the highest fire-retardant coating efficiency is achieved with content in the composition of asbestos-cement waste from 15.0 to 22.5%, aluminum-calcium slag from 7.5 to 10.0%. An increase in the content of fillers and technical drill for a rational area reduces the heat-shielding ability of the coating and reduces the fire-retardant effectiveness of the coating. Adding to the flame retardant composition sulfite-alcoholic membrane greatly improves the adhesion of the coating from the protected surface, which also affects the fire-protective ability of the coating, it grows to 76.0-81.0 minutes. Originality. Taking into account the theoretical preconditions, the choice of output components for a new fire protection composition has been carried out. Practical value. A new nonflammable spillway structure is developed, which allows the transfer of combustible materials into a group of heavier and increase fire resistance of building structures. On the developed fireproof composition the Ukrainian patent for utility model was obtained.

Fire protection behavior of layer-by-layer assembled starch–clay multilayers on cotton fabric

UV–Vis spectrometry and quartz crystal microbalance were used to measure the growth of these films as a function of the number of bilayers deposited, while scanning electron microscopy and transmission electron microscopy were used to visualize the morphology of the thin film coatings on the cotton fabric. Nanocomposites formed of cationic starch (CS) and clay introduced fire protection properties into the pure cotton fabric by layer-by-layer (LbL) technique. The optical properties and mass of the films were precisely controlled by the number of bilayers. In this case, CS and clay multilayer thin films were used to increase the thermal stability of the fabrics and improve the anti-flammable properties through the formation of a ceramic char layer and thermally stable carbonaceous structure at a high temperature. This study demonstrates the ability of the LbL technique to produce anti-flammable starch–clay nanocomposite thin films. Cone calorimetry showed the lower total heat release and heat release capacity of the LbL-coated fabric. The LbL-coated cotton samples exhibited a reduced afterglow time in vertical flame tests. An increased amount of residue indicates that the LbL technique is a simple method which can be used to produce eco-friendly flame retardant thin film coatings.

Getting a better insight into the chemistry of decomposition of complex flame retarded formulation: New insights using solid state NMR

This paper aims at developing an innovative approach to characterize the char residue of an intumescent coating obtained after a UL1709 furnace test. The intumescent formulation is based on an epoxy resin and contains numerous additives including zinc borate, ammonium polyphosphate and silicate fibers. The purpose is to characterize the numerous reactions that can occur upon burning using crossed methods including Electron Probe Micro-Analysis (EPMA), X-ray diffraction (XRD) and 1D/2D solid state Nuclear Magnetic Resonance (NMR). In particular, it emphasizes the potential of the advanced NMR technique namely two-dimensional Dipolar Heteronuclear Multiple Quantum Correlation (2D D-HMQC) NMR. As a result, EPMA evidenced that B/P and B/Si are located in the same domain suggesting the formation of boron-phosphorus and/or boron-silicone containing compounds on the sample surface. H3BO3 was identified by XRD as a main crystalline specie, additional species (e.g. SiO2, Zn4O(BO2)6) were also identified. The borate, silicate and phosphate chemical species were then characterized using 1D NMR but no definitive assignments could be given. To specify those assignments, 2D D-HMQC NMR was performed and the formation of amorphous borophosphates and borosilicates was evidenced emphasizing the chemical reactivity between the ingredients of the formulation. It was suggested that these species allow reinforcing the char and improving the fire protective properties of the coatings. This work highlights the particular interest of advanced NMR technique, which provides unique information on the characterization of intumescent char.

NATURE AND QUANTITY OF SILICATE FILLER INFLUENCE ON SILICATE PAINT PROPERTIES WITH LOWERED CONTENT OF VOLATILE COMPOUNDS

This article is addressed to the problem of composite silicate paint development. Silicate paints have a large field of application, for example, it can be used as a protective coating or decorative coating with protective properties in industrial and civil construction for many aims: walls plastering, painting of stone, glass, ceramic, brick, concrete, wood, metal and other surfaces. The main difference of developed paint in comparison with the existing analogues is a low organic component content. The mass content of acrylic polymers was 5%, while actual silicate paints have a high content of organic modifiers (up to 25 %). The modifiers additive improves the technological properties, stability and viability of silicate paint. However, a high content of organic components reduces the environmental and fire protection properties of silicate paint coating. In comparison with analogues, proposed silicate paint composition is free from drawbacks listed above. In response to low content of volatile organic compounds, the paint has long spreadable life and improved technological and operational characteristics. Hiding power, viscosity, and degree of chalking were determined by standard methods. All characteristics meet the requirements of GOST. Many silica high dispersion fillers like a sand, marshalite, perlite, aerosil were tested in silicate paint composition. It was found that the coatings obtained with aerosil additive in a quantity of 0.25 % had the minimal water absorption value (0.15 %) and ultimate adhesion strength (1.7 MPa).Forcitation:Lebedeva E.Yu., Kazmina O.V. Nature and quantity of silicate filler influence on silicate paint properties with lowered content of volatile compounds. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 3. P. 70-76

Intumescent coatings with improved properties for high-rise construction

The paper overviews the way of creating intumescent fire-protective compositions with improved properties by adding nano-and micro-sized supplements into them. Intumescent paints are inert at low temperatures, and at higher temperatures they expand and degrade to provide a charred layer of low conductivity materials. The modified intumescent paints are able to form a more stable charred layer than the classical paints. The stability of a charred layer is crucial if the fire safety in high-rise construction must be secured, because a weak charred layer will not provide a required fire endurance for steel bearing structures and they will break down in case of fire. The fire-protective properties of modified intumescent paints were estimated using an electrical furnace. Also the way of thermal decomposition of the paints was studied with thermogravimetric analysis. Results show that modified intumescent paints form a charred layer with improved fire-protective properties; it can serve as a thermal barrier for a longer period of time. Thermogravimetric analysis confirms this fact showing that the temperatures of full thermal decay in case of modified paints are higher than those of non-modified paints.

Transcriptome profiling of HepG2 cells exposed to the flame retardant 9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide (DOPO).

The flame retardant, 9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide (DOPO), has been receiving great interest given its superior fire protection properties, and its predicted low level of persistence, bioaccumulation, and toxicity. However, empirical toxicological data that are essential for a complete hazard assessment are severely lacking. In this study, we attempted to identify the potential toxicological modes of action by transcriptome (RNA-seq) profiling of the human liver hepatocellular carcinoma cell line, HepG2. Such insight may help in identifying compounds of concern and potential toxicological phenotypes. DOPO was found to have little cytotoxic potential, with lower effective concentrations compared to other flame retardants studied in the same cell line. Differentially expressed genes revealed a wide range of molecular effects including changes in protein, energy, DNA, and lipid metabolism, along with changes in cellular stress response pathways. In response to 250 μM DOPO, the most perturbed biological processes were fatty acid metabolism, androgen metabolism, glucose transport, and renal function and development, which is in agreement with other studies that observed similar effects of other flame retardants in other species. However, treatment with 2.5 μM DOPO resulted in very few differentially expressed genes and failed to indicate any potential effects on biology, despite such concentrations likely being orders of magnitude greater than would be encountered in the environment. This, together with the low levels of cytotoxicity, supports the potential replacement of the current flame retardants by DOPO, although further studies are needed to establish the nephrotoxicity and endocrine disruption of DOPO.

New fire retardant compositions for fire-resistant automatic curtains

The paper overviews the way by which intumescent fire retardant compositions act as fillers in fire-resistant automatic curtains. A several intumescent compositions, which form a heat-isolating charred layer when they are exposed to high temperatures, were produced and applied to the mineral-fabric basis of the curtain. Fire-protective properties of produced materials were assessed and compared with foreign specimens. Swelling coefficient and material’s fire durability were considered as operating parameters. The developed specimen which performed the best during fire tests was sent to accredited laboratory. It was proven, using standardized methods, that it’s fire resistance limit reaches 30 minutes. This proves an effective contribution of an intumescent compound and opens new ways of using them in fire curtains manufacturing.

Massive versus lightweight construction in residential building

AbstractMasonry as the primary form of construction is currently the most economic option for the building of multi‐storey apartment blocks in Germany in order to provide affordable housing. It can however also be stated that there is definitely further rationalisation potential in masonry construction, in contrast to lightweight construction.In comparison to masonry construction, lightweight building methods show no apparent economic advantages, the ecological balance is objectively equivalent and the fire protection and sound insulation properties have to be provided technically and constructively at high cost in order to comply with the same requirements.Under consideration of a realistic and objective assessment, there is therefore no reason to promote the use of lightweight building methods, such as timber‐frame, from their current status as niche products, especially for residential building.

Passive fire protection of ligno-cellulosic substrates using environmentally-friendly formulations

Here we report on our preliminary investigations on the passive fire protection property of potato starch on some ligno-cellulosic substrates, in the context of protecting them when present as structural components at Wildland Urban Interfaces (WUIs), during forest fires. The fire retardant properties of the formulations were evaluated using Thermo-gravimetric analysis (TGA), and Differential scanning calorimetric (DSC) and Bench-cone calorimetric measurements (BS 476-13: 1987). The results obtained have highlighted the efficiency of a potato starch coating, especially, in increasing the times to ignition, and also in reducing the flame intensities, thus warranting further investigations and developments in this area.

Diphenolic acid based biphosphate on the properties of polylactic acid: Synthesis, fire behavior and flame retardant mechanism

In an effort to impart fire protection properties to polylactic acid (PLA) utilizing renewable resources, diphenolic acid, a plant derived compound, was used to synthesize a biphosphate (hereinafter shortened as FR) that contains two types of phosphorus. The chemical structure of FR was confirmed by 1H NMR and 31P NMR. UL-94 V0 rating and LOI value of 27.4 for PLA were achieved at the FR loading content of 16 wt%. Besides, the heat release rate and total heat release of the flame retardant PLA were decreased remarkably in cone calorimetric tests. The significantly increased CO/CO2 ratio in cone tests and the presence of phosphorous containing compound in gas phase in TG-FTIR tests confirmed that the gas phase mechanism is mainly responsible for the improved flame retardant performance. Differential scanning calorimetric analysis showed the glass transition temperature of PLA composites have no change indicating no plasticizing effect of the FR. Finally, the tensile tests revealed that the ductility of PLA was sustained and tensile strength was depressed in a minimal content after the FR was incorporated. This work suggests a novel green strategy for improving flame retardancy performance of PLA and promoting the utilization of sustainable resource.

Comparative Environmental Life Cycle Analysis of Stone Wool Production Using Traditional and Alternative Materials

The mineral wool sector represents 10 % of the total output tonnage of the glass industry. The thermal, acoustic and fire protection properties of mineral wool make it desirable for use in a wide range of economic sectors especially in the construction industry for the creation of low energy buildings. The traditional stone wool manufacturing process involves melting raw materials, in a coke-fired hot blast cupola furnace, fiberization, polymerization, cooling, product finishing and gas treatment. The use of alternative raw materials as torrefied biomass and sodium silicate, is proposed as an alternative manufacturing process to improve the sustainability of stone wool production, particularly the reduction of gas emissions (CO2 and SO2). The present study adopts a life cycle analysis (LCA) approach to measure the comparative environmental performance of the traditional and alternative stone wool production processes; process data are incorporated into a LCA model using SimaPro 8 software with the Ecoinvent version 3 life cycle inventory database. The CML 2000 and Eco-Indicator99 methods are used to estimate effects on different impact categories. The Minerals and Land use impacts in Eco-Indicator99 and the Eutrophication impact in CML2000 increase between 2 and 4 % for the alternative process instead of the traditional one. Similarly, the ecotoxicity-related impacts increase between 9 and 24 % with the use of the alternative process. However these increases are compensated by concomitant impact decreases in other categories of impact; consequently, the three areas of impact grouped by individual Eco-indicator 99 impacts, show environmental benefits improvements between 6 and 15 % when using the alternative process based on torrefied biomass and silicate instead of the traditional process based on coke and cement use.

Influence of nano-silica on flame resistance behavior of intumescent flame retardant cellulosic textiles: Remarkable synergistic effect?

Abstract In recent years, nano-silica has emerged as a promising synergistic agent for improving the flame retardancy of intumescent flame retardant (IFR) polymer materials. However, few researches have been focused on the influence of the nano-silica on the flame retardant behavior of IFR cellulosic materials. In the paper, flame retardant mixtures of nano-silica and traditional IFR (NS-IFR) were applied on cotton fabric (CF) to investigate the synergistic effect of nano-silica on the thermal stability and fire resistance of IFR system. The results of the limited oxygen index (LOI) test and the vertical burning test (VBT) demonstrated that the flame retardancy of the treated cotton fabric was optimized when 4 wt% APP/PER/MEL was replaced by the 4% nano-silica. But it is impaired with increasing the concentration of nano-silica. Char residues, characteristic decomposition temperatures and heat release data from thermogravimetric (TG) and micro-scale combustion calorimeter (MCC) measurements revealed that appropriate addition of nano-silica into traditional IFR system can improve the fire protection properties of IFR-CF to a certain extent, but cause depress in thermal stability of IFR-CF. Therefore, for cellulosic textiles, it is not strongly recommended for use of nano-silica as synergistic agents in IFR system.

Determination of critical heat transfer for the prediction of materials damages during a flame engulfment test

SummaryThe personal protective equipment of workers exposed to heat can consist of materials with a relatively low melting point of approximately 250°C (membranes, zippers, and underwear). In particular, users of heat protective clothing (such as volunteer firefighters or industrial workers) are often consider using functional sports underwear for an optimized sweat transport and lower heat stress. However, in an emergency situation (flame engulfment), this kind of clothing can be potentially dangerous because of its low melting temperature. In this study, we investigated the critical heat transfer needed to melt synthetic underwear worn under heat protective clothing and developed a model to predict possible damage to material layers exposed to a flame engulfment condition. The fire protection properties of four clothing systems with varying layer structures were assessed. These combinations were tested on an instrumented manikin according to ISO 13506 (flame engulfment test). The thickness and thermal resistance of the individual garments were measured in order to examine the influence of each parameter on the performance of the complete clothing combination. The measurements showed that synthetic polyester underwear worn underneath heat protective clothing can withstand a 4s flame engulfment exposure without damage when the outer layer has an adequate thermal resistance. By using a simple heat transfer model, we could define a ‘critical thermal resistance’ as the thermal resistance of the outer layer required to prevent the melting of the underwear material. Copyright © 2016 John Wiley & Sons, Ltd.

Effect of boron compounds on fire protection properties of epoxy based intumescent coating

SummaryThe aim of this study was to investigate the effect of boron compounds on fire protection properties of intumescent coating based on ammonium polyphosphate (APP). Three kinds of boron compounds namely boric acid (BA), zinc borate (ZB) and melamine borate (MB) were used. Total amount of flame retardant additive was kept constant at 30 wt%, and boron compounds were used at three concentrations of 1, 3 and 5 wt%. Thermogravimetric analysis (TGA), Attenuated total reflectance–Fourier transform infrared spectroscopy (ATR‐FTIR) and fire test were conducted for the determining the fire performance of intumescent coating. According to fire test results, BA and MB showed synergistic effect at 1 wt% loading. ZB showed antagonistic effect at all concentrations. Fire protection effect of intumescent coating decreased as the added amount of boron compound increased regardless of boron compound type because of suppression of intumescence. Copyright © 2016 John Wiley & Sons, Ltd.

Experimental investigations on ultra-lightweight-concrete encased cold-formed steel structures: Part II: Stability behaviour of elements subjected to compression

In the field of structural engineering the design of cost efficient structures is highly important. This led to the development of cold-formed steel structures (CFS). An advanced CFS structure is introduced in this paper, which uses a special type of polystyrene aggregate concrete (PAC) as bracing material. This material has beneficial insulating and fire protection properties, which makes it a reasonable choice for residential buildings. An experimental programme was performed, to gain information on the flexural and axial behaviour of PAC-encased CFS elements and panels. Both unbraced and braced members were tested to gain information on increment of load-bearing capacity. Several different element sizes were used to be able to investigate the different stability failure modes (i.e. local, distortional and global). Results showed that PAC was able to restrain the global and distortional buckling modes of steel elements, thus providing “full bracing” in most practical cases. These results are introduced in two papers (Part I and II), detailing the failure modes, load increments and the effect of composite action. In this paper – Part II – the background and the results of compression tests are presented, and the bending experiments are detailed in Part I [1].

Experimental study on ultra-lightweight-concrete encased cold-formed steel structures Part I: Stability behaviour of elements subjected to bending

In the field of structural engineering the design of cost efficient structures is highly important. This led to the development of cold-formed steel structures (CFS). An advanced CFS structure is introduced in this paper, which uses a special type of polystyrene aggregate concrete (PAC) as bracing material. This material has beneficial insulating and fire protection properties, which makes it a reasonable choice for residential buildings. An experimental program was performed, to gain information on the flexural and axial behaviour of PAC-braced CFS elements and panels. Both unbraced and braced members were tested to gain information on increment of load-bearing capacity. Several different element sizes were used to be able to investigate the different stability failure modes (i.e. local, distortional and global). Results showed that PAC was able to restrain the global and distortional buckling modes of steel elements, thus providing “full bracing” in most practical cases. These results are introduced in two papers (Part I and II), detailing the failure modes, load increments and the effect of composite action. In this paper – Part I – the background and the results of bending tests are presented, and the experiments on the compression elements are detailed in Part II [1].

Surface thermodynamic parameters of modified wood

Energy characteristics of modified wood are studied in the paper. Application of this approach during the study of wooden materials allows forecasting the efficiency of modifiers for surface layer of wood. Phosphites, the efficient fire-retarders, were applied as modifiers. Using the example of a number of ethers with various alkoxy substituents of phosphorus atom, we have made an attempt to associate surface thermodynamic properties of modified wood and formation of properties for fire-, bio- and smoke protection. The dependence of change of energy characteristics and surface structure of wood on the nature of modifiers is determined. To study energy characteristics of wood, modified by various compounds, the following characteristics were used: σ surface tension and ΔG free enthalpy gradient. Easy Drop setting and the corresponding software were used to determine these values. According to the obtained data, the conclusion is made about the influence of modifiers on energy characteristics of wood. The high degree of modification (% P) causes bigger change of Gibbs energy, which determines formation of high-level fire-, bio- and smoke protection. Diethyl phosphite is the most efficient modifier. Formation of fire-protective properties stipulates long-term operation of wood and wood-based materials.