Flammability properties of fire-retardant timber

2021 ◽  
Vol 30 (2) ◽  
pp. 23-34
Author(s):  
O. N. Korolchenko ◽  
S. G. Tsarichenko ◽  
N. I. Konstantinova

Introduction. At present, the house-building industry, that produces timber structures, is in the process of sufficiently intensive development; however, high flammability of wood is the factor that restrains widespread use of timber in construction. The purpose of this work is to optimize the conditions of application of fire-retardant timber in the construction industry. The co-authors believe that the following problems are to be solved to attain this objective:● a comparative analysis of the fireproofing efficiency of several fire-proofing agents applied to different species of wood;● determination of the character of influence produced by fire proofing agents on fire retardant properties of wood.Methods of research. The fire proofing efficiency of sample compositions designated for wood was measured in compliance with the benchmark testing method specified in GOST R 53292 (p. 6.2). Experiments were launched pursuant to the methodology and with the help of measurement instruments specified in GOST 30244–94 (Method 2) to study the extent of the pine-tree timber flammability suppression. Critical values of thermal loads that may trigger inflammation and flame propagation in timber structures, that can be described using values of the critical surface density of the heat flow, were determined pursuant to GOST 30402–96 and GOST R 51032–97. The toxicity of combustion products and the smoke generation ability of fire-retardant pine-tree samples was assessed using standard methods and measurement instruments pursuant to GOST 12.1.044–89 (paragraphs 4.18 and 4.20).Research results and discussion. Biological flame retardants, integrated biological flame retardants that also ensure moisture protection, intumescent coatings, lacquers and varnishes that are ready for use and labelled as having group I and II fire-retardant efficiency pursuant to GOST R 53292, were studied in the course of this research project. The co-authors have identified that the mass loss by all fire-retardant compositions is below 9 %, if applied to samples of larch and oak-tree timber, same as if it were applied to standard samples of pine-tree timber.The findings of the experiment conducted to assess the flammability, ignitibility, flame propagation, smoke generation ability and toxicity of combustion products have proven the maximal efficiency of the composition designated for full-cell pressure impregnation of timber that ensures the properties of the material labelled as G1, V1, RP1, T2, D2.Conclusions. Hence, the research results have enabled the co-authors to assess the discrepancy between average mass loss values demonstrated by the samples of different species of timber (alder, linden, pine-tree, larch, and oak-tree).The comprehensive study of flammability properties of timber, treated by compositions that vary in their chemical composition and mode of action of the fire proofing agent, enabled the co-authors to identify the impact produced by versatile fire-proofing agents on different flammability properties of pine-tree timber with regard taken of the fire-safe use of construction materials and constructions of buildings and structures.

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3979
Author(s):  
Anna Strąkowska ◽  
Sylwia Członka ◽  
Karolina Miedzińska ◽  
Krzysztof Strzelec

The subject of the research was the production of silsesquioxane modified rigid polyurethane (PUR) foams (POSS-Cl) with chlorine functional groups (chlorobenzyl, chloropropyl, chlorobenzylethyl) characterized by reduced flammability. The foams were prepared in a one-step additive polymerization reaction of isocyanates with polyols, and the POSS modifier was added to the reaction system in an amount of 2 wt.% polyol. The influence of POSS was analyzed by performing a series of tests, such as determination of the kinetics of foam growth, determination of apparent density, and structure analysis. Compressive strength, three-point bending strength, hardness, and shape stability at reduced and elevated temperatures were tested, and the hydrophobicity of the surface was determined. The most important measurement was the determination of the thermal stability (TGA) and the flammability of the modified systems using a cone calorimeter. The obtained results, after comparing with the results for unmodified foam, showed a large influence of POSS modifiers on the functional properties, especially thermal and fire-retardant, of the obtained PUR-POSS-Cl systems.


2020 ◽  
Vol 2020 (2) ◽  
pp. 64-69
Author(s):  
I Khaidarov ◽  
◽  
R Ismailov

This article presents studies of fire resistance in the treatment of expanded vermiculite, which depends on the size of the dispersed particles and the orientation of the granules, their moisture and temperature. It has been studied that one of the interesting and important in practice properties of vermiculite is its ability to swell and turn into a lightweight effective material for imparting fire resistance. The properties and compositions of vermiculite from the Tebinbulak deposit are studied, from which a flame-retardant suspension is prepared for processing textile materials based on vermiculite dissolved in orthophosphoric acid and alkali in an aqueous medium. When modifying materials with developed flame-retardant suspensions, it is possible to obtain fire-resistant textile materials that meet the requirements of GOST for fire resistance, smoke generation and other physical and mechanical properties.


Author(s):  
Yu. Tsapko ◽  
◽  
А. Tsapko ◽  
O. Bondarenko ◽  
V. Lomaha ◽  
...  

Abstract. The processes of creation of fire-retardant varnish for wood consisting of a mixture of inorganic and polymeric substances are investigated in the work. It is established that the optimization of the inorganic component leads to a directional ratio of mineral acids and urea capable of effective fire protection of the material. Studies have shown that at the initial temperature of gaseous combustion products T = 68 °C, when exposed to the radiation panel, the untreated sample ignited after 146 s, the flame spread over the entire surface, instead, the sample fire-protected varnish did not ignite, the maximum temperature was 105 °C. In this case, as evidenced by the results of heat resistance, there is a change in the structure of the protective film of the coating. The thickness of the protective layer increases due to the decomposition of the composition, which leads to inhibition of oxidation in the gas and condensed phase, change the direction of decomposition towards the formation of non-combustible gases and combustible coke residue, reduce material combustion and increase flammability index. The coating under the influence of high temperature promotes the formation of a heat-insulating layer of coke, which prevents burning and the passage of high temperature to the material, which is confirmed by the absence of the process of ignition of fire-retardant wood. Features of braking of process of ignition and distribution of a flame of the wood processed by a varnish which consist in several aspects are established. This is the formation of a heat-insulating layer of coke, which prevents burning and the passage of high temperatures to the material, which is confirmed by the absence of the process of ignition of fire-retardant reeds. This indicates the possibility of targeted control of high temperature transfer processes to organic material through the use of special coatings for wood products.


Fire Safety ◽  
2019 ◽  
pp. 66-71
Author(s):  
P. V. Pastuhov ◽  
V. V. Kochubei ◽  
O. I. Lavrenyuk ◽  
B. M. Mykhalichko

Introduction. The development of modern technologies and the elaboration of new materials facilitates the wide use of epoxy resins for instance in industries. Particular attention deserves the various fire retardant coatings making. These coatings are increasingly used to increase fire resistance of details and designs made of metals, plastics, wood in various industrial and civil constructions, and in transport. The very perspective mode producing the effective fire retardant coatings is the direct introduction into the polymeric matrix of epoxy resins of reactive fire retardant agents. Purpose. The aim of this work is to study the effect of the elaborated fire retardant on the ability of epoxy-amine composites modified with copper(II) carbonate to resist the spread of the flame, as well as the effects of water and chemicals. Metods. The flame propagation rate on the surface of horizontally located experimental samples was determined according to all-State Standard 28157-89. Water and chemical resistance were evaluated by a gravimetric method on the polymer mass film change after exposure to distilled water and corrosive media for a certain period of time. Results. The results of experimental studies have shown that samples of the epoxy-amine composites containing 20, 40 and 80 mass parts of CuCO3 per 100 mass part of the binding agent do not propagate the flame horizontally at all. At that, duration of free combustion of these polymer samples did not exceed 2 min. It has been found too that the penetrability of water and chemicals through films based on epoxy-amine composites modified with CuCO3 is reduced due to the formation of chemical bonds between copper(II) carbonate and polyethylenepolyamine. The lowest level of the equilibrium absorption in water and 10% aqueous solutions of H2SO4 and NaOH was watched for samples of those composites that contained 20 mass parts of CuCO3 per 100 mass parts of binder. Conclusion. When studying the effect of copper(II) carbonate on the flame propagation rate, it was found that the epoxy-amine composites containing >20 mass parts of CuCO3 per 100 mass parts of the binding agent, do not propagate the flame and so these are self-extinguishing. The copper(II) carbonate addition to epoxy polymers reduces their sorption capacity in water and solutions of alkalis and acids. These data are the basis to future develop the chemically resistant fire retarding coatings based on epoxy-amine composites modified with copper(II) carbonate. Keywords


Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4113
Author(s):  
Ruiqing Shen ◽  
Tian-Hao Yan ◽  
Rong Ma ◽  
Elizabeth Joseph ◽  
Yufeng Quan ◽  
...  

Metal–organic frameworks (MOFs) are emerging as novel flame retardants for polymers, which, typically, can improve their thermal stability and flame retardancy. However, there is a lack of specific studies on the thermal decomposition kinetics of MOF-based polymer composites, although it is known that they are important for the modeling of flaming ignition, burning, and flame spread over them. The thermal decomposition mechanisms of poly (methyl methacrylate) (PMMA) have been well investigated, which makes PMMA an ideal polymer to evaluate how fillers affect its decomposition process and kinetics. Thus, in this study, UiO-66, a common type of MOF, was embedded into PMMA to form a composite. Based on the results from the microscale combustion calorimeter, the values of the apparent activation energy of PMMA/UiO-66 composites were calculated and compared against those of neat PMMA. Furthermore, under cone calorimeter tests, UiO-66, at only 1.5 wt%, can reduce the maximum burning intensity and average mass loss rate of PMMA by 14.3% and 12.4%, respectively. By combining UiO-66 and SiO2 to form a composite, it can contribute to forming a more compact protective layer, which shows a synergistic effect on reducing the maximum burning intensity and average mass loss rate of PMMA by 22.0% and 14.7%, respectively.


Author(s):  
Lyubov Vakhitova ◽  
◽  
Nadiya Taran ◽  
Konstantin Kalafat ◽  
◽  
...  

Purpose. Identification of the main directions of evolution of scientific researches concerning development and improvement of fire protective reactive coatings of intumescent type for steel constructions. Methods. Analysis of literature sources, study and generalization of information, classification and modeling of chemical processes. Results. As a result of the performed researches it has been shown that of all the developed reactive fire protection systems for increasing the fire resistance of steel structures the intumescent composition of ammonium polyphosphate/ pentaerythritol / melamine / polymer is the most widespread and economically justified. To reduce the cost of fire protection measures, it is necessary to improve the coatings of the intumescent type in the following main areas: increasing of fire protection efficiency with a decrease in the thickness of the fire protection layer; prolongation of life time with strengthening of resistance to external factors; reducing the cost of the prescription composition of intumescent paint due to the use of nanomaterials. Scientific novelty. It has been established that nanoclays, nanooxides of metals and silicon, LDH compounds and their analogues should be considered the most promising and multifunctional. The presence of nanomaterials in intumescent compositions allows to increase the environmental parameters of fire-retardant treatment due to the rejection of halogen flame retardants, boron compounds, formaldehyde resins. In addition, the presence of nanocompounds in intumescent coatings significantly reduces smoke in fire. Practical significance. The conclusions obtained from the literature review are of practical importance for the development of new approaches to the design of fire-fighting materials with improved performance through the use of nanomaterials, which provides a strong fire retardant foam char layer and provides rigidity of the insulation frame.


Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 664 ◽  
Author(s):  
Maria Paola Luda ◽  
Marco Zanetti

Polymers are intrinsically flammable materials; hence, fire retardance (FR) is required in their most common applications (i.e., electronic and construction, to mention some). Recently, it has been reported that cyclodextrin (CD) and cyclodextrin derivatives are beginning to be introduced into Intumescent Fire Retardant (IFR) formulations in place of pentaerythritol, which is used in IFRs that are currently on the market. Since IFRs are of less environmental concern than their hazardous halogen containing counterparts, the use of natural origin compounds in IFRs provides a way to comply with green chemistry issues. BCD and BCD derivatives presence in IFR mixtures promotes a higher yield of blowing gases and char when polymeric materials undergo combustion. Both processes play important roles in intumescence. The key rule to obtain in insulating compact char is the good dispersion of the nanoparticles in the matrix, which can be achieved by functionalizing nanoparticles with BCD derivatives. Moreover, CD derivatives are attractive because of their nanosized structure and their ability to form inclusion complexes with many compounds used as FR components, reducing their release to the environment during their shelf life of FR items. Often, fire retardance performed by BCD and BCD derivatives accompanies other relevant properties, such as improved mechanical resistance, washability resistance, self healing ability, thermal conductivity, etc. The application of CD fire retardant additives in many polymers, such as poly(lactic acid), poly(propylene), poly(vinyl acetate), poly(methyl methacrylate), linear low density poly(ethylene), polyamides, and polyesters are comprehensively reviewed here.


RSC Advances ◽  
2020 ◽  
Vol 10 (20) ◽  
pp. 12078-12088
Author(s):  
Hui Wang ◽  
Xiaosheng Du ◽  
Shuang Wang ◽  
Zongliang Du ◽  
Haibo Wang ◽  
...  

A novel reactive intumescent fire retardant hexa-[4-[(2-hydroxy-ethylimino)-methyl]-phenoxyl]-cyclotriphosphazene (HEPCP), containing both cyclotriphosphazene and Schiff base structures, is successfully prepared.


Polymers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 180 ◽  
Author(s):  
Neeraj Mandlekar ◽  
Aurélie Cayla ◽  
François Rault ◽  
Stéphane Giraud ◽  
Fabien Salaün ◽  
...  

In this study, two different types of industrial lignin (i.e., lignosulphonate lignin (LL) and kraft lignin (DL)) were exploited as charring agents with phosphorus-based flame retardants for polyamide 11 (PA11). The effect of lignins on the thermal stability and fire behavior of PA11 combined with phosphinate additives (namely, aluminum phosphinate (AlP) and zinc phosphinate (ZnP)) has been studied by thermogravimetric analysis (TGA), UL 94 vertical flame spread, and cone calorimetry tests. Various blends of flame retarded PA11 were prepared by melt process using a twin-screw extruder. Thermogravimetric analyses showed that the LL containing ternary blends are able to provide higher thermal stability, as well as a developed char residue. The decomposition of the phosphinates led to the formation of phosphate compounds in the condensed phase, which promotes the formation of a stable char. Flammability tests showed that LL/ZnP ternary blends were able to achieve self-extinction and V-1 classification; the other formulations showed a strong melt dripping and higher burning. In addition to this, cone calorimetry results showed that the most enhanced behavior was found when 10 wt % of LL and AlP were combined, which strongly reduced PHRR (−74%) and THR (−22%), due to the interaction between LL and AlP, which not only promotes char formation but also confers the stability to char in the condensed phase.


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