Fire Retardant Effect Research Articles

Mechanisms of the Action of Fire-Retardants on Reducing the Flammability of Certain Classes of Polymers and Glass-Reinforced Plastics Based on the Study of Their Combustion.

In the present review, using an integrated approach based on the experimental and theoretical study of the processes of thermal decomposition and combustion of practically important polymers, such as polymethyl methacrylate, polyethylene, and glass-fiber-reinforced epoxy resin, the features of the mechanism for reducing the combustibility of these materials with phosphorus-containing flame-retardants (FR), as well as graphene, are identified. A set of original experimental methods was developed and applied that make it possible to study the kinetics of thermal decomposition and the thermal and chemical structure of the flames of the studied materials, including those with FR additives, as well as to measure the flame propagation velocity, the mass burning rate, and the heat fluxes from the flame on the surface of a material. Numerical models were developed and tested to describe the key parameters of the flames of the studied polymeric materials. An analysis of the experimental and numerical simulation data presented showed that the main effect of phosphorus-containing fire-retardants on reducing the combustibility of these materials is associated with the inhibition of combustion processes in the gas phase, and the effect of adding graphene manifests itself in both gas and condensed phases.

Development of NaOH-borax crosslinked PVA-xanthan gum-lignin hydrogel as green fire retardant coating

In this paper, we report synthesis of green fire-retardant hydrogels comprising polyvinyl alcohol (PVA), xanthan gum (XG), and lignin nanoparticles (LNP, synthesized using nanoprecipitation). The hydrogel network was achieved through crosslinking by borax and NaOH. XPS analysis of LNPs revealed no change in chemical state of lignin after formation of nanoparticles. The hydrogels were characterized using FTIR, FESEM, and thermogravimetric analysis. The rheological properties of the hydrogels were measured. Among different hydrogels, the best combination of properties was achieved for hydrogel PX3B0.4N2L20, viz. elastic modulus (G′) = 23,428.57 Pa (indicating strong elastic network), crosslinking density = 870,350.12 kmol m−3 and mesh size of 5.60 nm. High char formation (34.61 wt%) by PX3B0.4N2L20 hydrogel helped in enhancing fire retardancy. With coating of PX3B0.4N2L20 hydrogel, limiting oxygen index (LOI) for cotton cloth improved from 20 % to 39 %. Kinetic analysis of TGA data yielded the highest activation energy of 493.8 kJ mol−1 for hydrogel, which corroborated the LOI test results. The cone calorimeter tests of PX3B0.4N2L20 hydrogel also revealed the least peak heat release rate of 90.3 ± 10 kW/m2 and the least total heat release rate of 1.56 ± 4 MJ/m2. In summary, PVA-based hydrogels synthesized in this study have high potential as effective and biodegradable fire retardant coatings.

Effect of fire retardants on germination of agricultural seeds

The occurrence of fires in agricultural areas grown with winter maize has become recurrent in the Central-West region of Brazil, since the harvest occurs in the dry season in the region. Fire retardants can be used as an indirect control of fire; they consisted of chemical products that can remain in the straws or on the soil after the fire extinction. The objective of this work was to evaluate the effect of two short-term fire retardants (Phos-Chek WD881® and Hold Fire®) and a hydrogel (alternative fire retardant) on germination of rice (Oryza sativa), common bean (Phaseolus vulgaris), millet (Pennisetum glaucum), maize (Zea mays), and soybean (Glycine max) seeds. The control treatment consisted of only distilled water. The seed germination percentage and speed index, mean time for germination, and seedling growth (shoot and root length and dry weight) were evaluated. A completely randomized experimental design was used, with 4 replications per treatment; each experimental unit consisted of 100 seeds maintained in germination chambers (30 °C and photoperiod of 12 hours). The effects of the fire retardants and hygroscopic polymer on the seed germination and seedling initial growth were specific, and no significant effect caused by the variations in the concentrations of the fire retardants was found.

The fabrication of phytate and LDH-based hybrid nanosheet towards improved fire safety properties and superior smoke suppression of intumescent flame retardant LDPE

An effective fire retardant system was developed composed by traditional intumescent flame retardant (IFR) and a new-typed nano-synergist (PAMA-SDBS-LDH, P@L), and their synergistic effect and mechanism on the thermal stability and flammability properties of low-density polyethylene (LDPE) was comprehensively studied. Briefly, the nano-synergist was successfully prepared by using melamine, phytic acid and Zn-Ni-Al layered double hydroxide (LDH) according to hydrothermal method. By adding 0.5% PAMA-SDBS-LDH and 29.5% IFR, the fire retardant properties of LDPE composite (LDPE/I/P@L) reached V-0 rating in UL-94 test. The total smoke production of LDPE/I/P@L decreased by 69.8% compared with LDPE. It is confirmed that PAMA-SDBS-LDH nanosheet is an efficient synergist to promote the formation of high-quality char layer via multiple fire retarding mechanisms. The good mechanical properties of LDPE/IFR system are also maintained by incorporating PAMA-SDBS-LDH. Undoubtedly, this study will provide valuable insights into improving the fire retardant efficiency and practical application of traditional IFR.

Fire-retardant effect of titania-polyurea coating and additional enhancement via aromatic diamine and modified melamine polyphosphate

Polymeric materials and composites are well suited to support structures in marine conditions due to their corrosion resistance. However, their low glass transition temperature makes them vulnerable to softening at high temperatures. Hence, fire retardancy is a key aspect if these materials are selected to ensure stiffness under flammable conditions. In this paper, a fire-retardant polyurea coating for industrial applications is proposed. The aromatic diamine and aliphatic diisocyanate are believed to have a synergistic effect in improving flame properties. Moreover, various combinations of flame-retardant additives with aromatic and aliphatic-based polyurea are mixed to further improve fire-retardancy. Through the characterizations of their glass transition temperature and delay in the ignition, it indicates that the combination of Talc and melamine polyphosphate may provide an outstanding enhancement for the Titania-polyurea coating, and such enhancement may improve its original tensile and compression strength, and surface hardness as well.

Small multiamine molecule enabled fire-retardant polymeric materials with enhanced strength, toughness, and self-healing properties

The combination of high fire retardancy, high strength, and great toughness as well as good healability is essential for successful real-world applications of polymeric materials in the fields of packaging, electronics & electrics, and optical devices. To date, there have been few successes in achieving such performance portfolios in polymers due to their different and even mutually exclusive governing mechanisms. Inspired by the nanoconfinement effect that governs the unique mechanical properties of spider silk, we, herein, rationally design a multifunctional small molecule, HCPA, that can serve as a fire retardant and hydrogen-bond crosslinker for poly(vinyl alcohol) (PVA). Benefiting from the dual-phase fire-retardancy effect and the dynamic cross-linking effect, the addition of 5.0 wt% of HCPA enables PVA to achieve a desired self-extinguishment in combination with a high tensile strength of 133 MPa and a toughness of 112 MJ/m3. In addition, the as-prepared polymer material exhibits a high healing efficiency of over 90% (based on strength) if triggered by water. This proof-of-concept opens numerous opportunities for the creation of self-extinguishing, strong, tough, and self-healing polymers for many high-end applications in the above-mentioned industries.

A Si-containing polyphosphoramide via green chemistry for fire-retardant polylactide with well-preserved mechanical and transparent properties

A solvent-free green approach has been developed to synthesize a Si-containing polyphosphoramide (DM-Si) for creating transparent and fire-retardant PLA materials. • A green strategy for a Si-containing polyphosphoramide (DM-Si) was developed. • 1 wt% DM-Si significantly improves the fire safety of PLA. • The toughness of PLA increases to 4.7 MJ/m 2 but maintaining its tensile strength. • The transparency of PLA fire-retardant composites is well-preserved. Renewable polylactide (PLA) features good biodegradability, high optical transparency and mechanical strength. However, inherent flammability severely restricts its practical applications in packaging, fabric and electronics. Polyphosphoramides have recently demonstrated high fire-retardant effectiveness in PLA, but their synthesis usually involves the use of a large volume of toxic organic solvents, in addition to their negative impacts on the transparency of PLA. Herein, we report a one-pot green solvent-free approach for massively synthesizing a silicon (Si)-containing polyphosphoramide (DM-Si). The results show that with only 1.0 wt% of DM-Si, the resultant PLA material exhibits desirable fire retardancy, e.g., a UL-94 V-0 rating and a limiting oxygen index of 27.9%, and a 68% increase in toughness relative to virgin PLA. Moreover, both the tensile strength and transparency of PLA are well-preserved. This work provides an eco-benign yet facile strategy for the synthesis of efficient flame retardants for bioplastics with balanced mechanical strength and transparency, which hold great promise as sustainable materials for many industrial applications.

Governing effects of melt viscosity on fire performances of polylactide and its fire-retardant systems

SummaryExtreme flammability of polylactide (PLA) has restricted its real-world applications. Traditional research only focuses on developing new effective fire retardants for PLA without considering the effect of melt viscosity on its fire performances. To fill the knowledge gap, a series of PLA matrices of varied melt flow index (MFI) with and without fire retardants are chosen to examine how melt viscosity affects its fire performances. Our results show that the MFI has a governing impact on fire performances of pure PLA and its fire-retardant systems if the samples are placed vertically during fire testing. PLA with higher MFI values achieves higher limiting oxygen index (LOI) values, and a lower loading level of fire retardants is required for PLA to pass a UL-94 V-0 rating. This work unveils the correlation between melt viscosity and their fire performance and offers a practical guidance for creating flame retardant PLA to extend its applications.

Synergistic Effect of APP and TBC Fire-Retardants on the Physico-Mechanical Properties of Strandboard.

This study explored the feasibility of fabricating fire-retardant strandboard with low mechanical properties deterioration to the physico-mechanical properties. A hybrid fire-retardant system of ammonium polyphosphate (APP) and 1,3,5-tris(2,3-dibromopropyl)-1,3,5-triazinane-2,4,6-trione (TBC) was investigated. Thermogravimetric analysis results show that both APP and TBC enhance the thermal stability and incombustibility of wood strands. An infrared spectrum was applied to investigate the effect of flame retardants on the curing behaviors of polymeric diphenylmethane diisocyanate (PMDI) resin. Based on the results of limiting oxygen index (LOI) and Cone calorimetry (CONE), APP and TBC both lead to a higher fire retardancy to strandboard. It is worth mentioning that the two flame retardants lead to evidently differential influences on the modulus of rupture (MOR), modulus of elasticity (MOE), internal bond (IB), and water-soaking thickness swelling (TS) properties of strandboard. Hence, a hybrid flame retardant is prominent in manufacturing strandboard with both good fire retardant and satisfying physico-mechanical properties.

ИССЛЕДОВАНИЕ ВЛИЯНИЯ АНТИПИРЕНОВ НА ГОРЮЧЕСТЬ И ПОКАЗАТЕЛЬ ТЕКУЧЕСТИ РАСПЛАВА АЛИФАТИЧЕСКИХ ПОЛИАМИДОВ

The paper presents the results of a study of the effect of fire retardants on the flammability and melt flow rate of aliphatic polyamides of the PA 66L, PA 610L, PA 66KS grades. The degree of this influence depends on the grade of polyamide, the type of fire retardant and its quantitative content. Among the selected grades of polyamides, polyamide PA 66L has the highest fluidity. The efficiency of using decabromodiphenyloxide and antimony trioxide to reduce the duration of residual combustion of polyamides of the studied brands is shown, compositions related to the category of «self-extinguishing» are determined.

Эффективность комбинации огнезащитных вспучивающихся покрытий для стальных конструкций

Introduction. Steel constructions are one of the most widely used and rational types of constructions for buildings and structures of various functional purposes. As advantages in comparison with constructions made of other materials, their high load-bearing capacity, industriality, ease of installation are noted. One of the disadvantages is low fire resistance. A common way to increase the fire resistance of metal structures is considered to be the use of fire protection products, the experience of which has been developed for many decades. However, as practice and the results of fire tests show, it is quite difficult to obtain a stable and reliable result using such fire-retardant systems. Goals and objectives. Analysis of work on the creation of effective flame retardant technologies. Development of formulations of thin-layer bulging coatings, taking into account their use as protective layers of combined flame retardant systems. Evaluation of the characteristics of the resulting foam layers of the developed coatings. Conducting a comparative analysis of the effectiveness of combined technologies of intumescent fire protection. Methods. The research was based on experiments conducted in a firing furnace, with the possibility of isothermal or dynamic radiation heating of the surface of a steel sample up to 1000 °С. The installation makes it possible to study the properties and structure of the expanded layer of flame-retardant coatings and their thermal insulation ability under unilateral thermal exposure. Thermoelectric converters were used to measure the temperature on the unheated surface of the sample. Results and discussion. The conducted analysis of the works testifies to numerous studies in this direction. The development of intumescent systems is of great interest. In the course of the research, the authors have developed various formulations of thin-layer flame retardant coatings, as well as their combinations based on innovative chemical technologies for steel constructions, taking into account the availability and manufacturability of the raw materials used. The results of studies on the evaluation of the thermal insulation ability of the developed foam systems have shown that the fire-retardant effect due to the combination of various swelling coatings can be increased by 30 % or more. Conclusion. A new scientific direction has been formed related to the creation of combinations of bulging flame-retardant coatings for various construction structures. The establishment of various options for the combination of the use of fire-resistant coatings opens up wide opportunities for the creation of effective protection of various building materials and structures from the effects of fire. Keywords: combined fire protection, intumescent coatings, swelling, foam, thermal insulation ability, steel constructions.

Assessment of the fire retardant effect potential of carbonized cow horn ash additive in banana peduncle fibre reinforced polyester composites

Purpose This paper aims to examine the fire retardant property potentials of cow horn ash particles (CHAp) bio-additive and aluminium trihydrate (AH), a traditional inorganic fire-retardant additive, respectively, in banana peduncle fibre (BPF) reinforced polyester composites. An attempt was made to comparatively analyse the fire retardant capacity potentials of CHAp, a bio-material waste that is readily available, at no cost, as a potential fire retardant material for composites manufacture with a conventional inorganic fire retardant additive (AH). Design/methodology/approach The fibre used in this research was derived from the banana peduncle. The matrix is unsaturated polyester. A scanning electron microscope was used to analyze the particle size of the carbonized CHAp. The composites were compounded using 0%, 2.5%, 5%, 7.5% and 10% of CHAp and AH, respectively. A cone calorimeter instrument was used in the analysis to obtain combustion information of CHAp and AH formulated polyester-BPF composites. Test samples were cut to the dimensions of 100 × 100 mm. All materials are conditioned at 23 ± 30 °C and the relative humidity of 50 ± 5% for 24 h before testing. The samples were wrapped with aluminium foil around the back and edges before placing the samples on the holder and then into the cone calorimeter. The samples were backed with a non-combustible insulating refractory material (brick). The samples were orientated horizontally and exposed to irradiances of 50 kW/m2 at a temperature of approximately 6000 °C. The samples were pilot ignited and ran in triplicate; the average readings of the three runs were taken. Findings The results obtained from the analysis depicted similar fire retardant properties for formulations with CHAp and AH, respectively. Composites formulated with CHAp exhibited delayed ignition time of 25%, increased end of burning time of 14.24% and reduced total heat release rate of 9.07% for the developed composites. The developed BPF/CHAp/polyester composites yield composites with fire retardancy, which would find relevance in the engineering material industry. Originality/value CHAp, therefore, would suffice as an alternative to the inorganic, expensive and non-environmental friendly, conventional fire retardant additives used in composites manufacture.

Fire-Retardant Synergy of Tris(1-Methoxy-2,2,6,6-Tetramethyl-4-Piperidinyl)Phosphite and Melamine Hydrobromide/Aluminum Diethylphosphinate in Polypropylene

The fire-retardant synergy of tris(1-methoxy-2,2,6,6-tetramethyl-4-piperidinyl)-phosphite (NORPM) and melamine hydrobromide (MHB)/aluminum diethylphosphinate (ADEP) in polypropylene (PP) was characterized by UL-94 tests, limiting oxygen index (LOI) determination and cone calorimetry tests (CCT). NORPM exhibits an exceptional synergy in PP. The LOI and fire-retardant effectivity (EFF) of S-3 (the loadings of MHB and ADEP 1.00 and 1.50 wt%, respectively, no NORPM) were 19.0% and 0.48%, respectively, however, the LOI and EFF of S-15 (the loadings of NORPM, MHB and ADEP 0.2, 1.00 and 1.50 wt%, respectively) significantly increased to 25.5% and 2.85%, respectively, synergistic effectivity (SE) of NORPM is 2.03, and the fire-retardant rating was improved from none to UL 94 V-2 and the total heat release (THR) and peak heat release rate (PHRR) dropped obviously by adding the 0.2 wt% NORPM. The analysis by thermogravimetry-mass spectrum analysis (TG-MS) of the PP samples and the residues in the CCT revealed that NORPM, MHB and ADEP induced the synergy primarily by the following modes: CH3O·, aminyl radicals, CH3·and nitro radicals formed through the cracking of NORPM, along with the free radicals such as PO·, PO2 · and HPO· pyrolyzed from ADEP and HBr from MHB, which quenched the active radicals, such as HO·, H·, ROO·, R· and broke down the radical source. The chain oxidation reaction of combustion was accordingly interrupted, which brought about the more exceptional fire-retardant effect than that of MHB/ADEP.

The Effects of Some Phosphorus-Containing Fire Retardants on the Properties of Glass Fibre-Reinforced Composite Laminates Made from Blends of Unsaturated Polyester and Phenolic Resins

This study investigated the effects of phosphorus fire retardants (FRs) in matrices from co-cured blends of an unsaturated polyester (UP) with inherently fire-retardant phenolic resoles (PH) on the mechanical and flammability properties of resultant glass fibre-reinforced composites. Three different phenolic resoles with UP have been used: (i) an ethanol soluble (PH-S), (ii) an epoxy-functionalised (PH-Ep), and (iii) an allyl-functionalised resin (PH-Al) with two different phosphorus FRs: resorcinol bis (diphenyl phosphate) (RDP) and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO). The flammabilities of the resultant composites were evaluated using cone calorimetry and the UL-94 test. Cone calorimetric results showed reductions in peak heat release rate (PHRR) and total heat released (THR) as expected compared to those of UP and respective UP/PH composite laminates without FRs. UL-94 tests results showed that while all composites had HB rating, FR containing samples self-extinguished after removal of the flame. The mechanical properties of the composites were evaluated using flexural, tensile and impact tests. All FRs reduced the mechanical properties, and the reduction in mechanical properties was more severe in UP/PH-S (least compatible blends) composites with FRs than in UP/PH-Al (most compatible blends) composites with FRs. Amongst the different composites, those from UP/PH-Al with DOPO showed the best fire retardancy with little deterioration of mechanical performance.

The evaluation of the fire-retardant efficiency of intumescent coatings of steel structures exposed to high-temperature gas flows

Introduction. High-temperature gas flows often occur in case of a fire at oil and gas facilities; gas flows out of holes, cracks, ruptures in depressurized items of equipment and pipelines. The fire-retardant efficiency of intumescent coatings of steel structures, exposed to high-temperature gas flows, plummets. Hence, the task of developing a methodology for the adequate assessment of their fire-retardant efficiency is relevant.Goals and objectives. The purpose of the study was to develop a methodology for evaluating the fire-retardant efficiency of intumescent coatings for steel structures exposed to high-temperature gas flows and experimentally evaluate the fire-retardant efficiency of various intumescent coatings. The following research-focused tasks were solved: the evaluation of the velocity of high-temperature gas flows leaving depressurized items that normally operate under pressure; the analysis of the methodology designated for identifying the fire-retardant efficiency of intumescent coatings of steel structures in a calm (sedentary) gaseous medium; the development of a method for evaluating the fire-retardant efficiency of intumescent coatings of steel structures exposed to high-temperature gas flows; the experimental evaluation of the fire-retardant efficiency of various intumescent coatings in a high-temperature gas flow.Methods. The velocity of high-temperature gas flows, leaving depressurized items that normally operate under pressure, has been calculated. The co-authors have analyzed the established methodology used to identify the fire-retardant efficiency of intumescent coatings of steel structures in a steady (sedentary) environment, where gas temperature in a furnace is the only factor taken into account. The co-authors propose a method for evaluating the fire-retardant efficiency of intumescent coatings of steel structures exposed to high-temperature gas flows, which takes into account gas flow temperature and velocity. To evaluate the fire-retardant efficiency of an intumescent coating exposed to a high-temperature gas flow, a coefficient of relative fire resistance is introduced. An experimental evaluation of various intumescent coatings is carried out. It shows a substantial fire- retardant efficiency decrease in a high-temperature gas flow that fosters the hydrocarbon temperature regime.Results and discussion. Mutual aerodynamic and thermal effects of a gas flow substantially reduce the fire- retardant efficiency of intumescent coatings of steel structures, and this is proven by the results of experiments conducted according to the proposed method. The method for evaluating the fire-retardant effectiveness of intumescent coatings of steel structures takes into account the temperature and velocity of a gas flow that affects the sample.Conclusions. It is relevant and necessary to evaluate the fire-retardant efficiency of intumescent coatings of steel structures at oil and gas facilities, operating under pressure, since a substantial decrease in their fire-retardant efficiency is observed in high-temperature gas flows.

Evaluating the use of calcium hydrogen phosphate dihydrate as a mineral‐based fire retardant for application in melamine‐urea‐formaldehyde (MUF)‐bonded wood‐based composite materials

SummaryCalcium hydrogen phosphate dihydrate (DCPD) was evaluated for its potential as a mineral fire retardant (FR) for application in melamine‐urea‐formaldehyde (MUF)‐bonded wood composites. The efficacy as FR was studied in melamine‐urea‐formaldehyde (MUF)‐bonded three‐layer particleboard as a function of addition quantities of 10‐, 20‐ and 30 wt%. Resistance to fire and mechanical properties were determined by measuring the self‐extinguishing time after flame exposure and internal bond strength, respectively. Combustion behavior was examined on samples with 20 wt% DCPD addition by performing cone calorimetry experiments. The efficacy of DCPD was evaluated by determining the heat release, total heat release rate, smoke production, and smoke production rate and compared to another promising mineral‐based fire‐retardant composition (FRC) based on hydroxyapatite (HA) with deliquescent salt and HA alone. The effect of FR on the curing behavior of MUF in relation to mechanical properties was determined through viscosity measurements of MUF with 10 wt% addition of FR. The results confirmed the fire‐retardant characteristics of DCPD in wood composites, albeit at higher application rates when compared to the FRC, however with no negative impact on resin curing time or mechanical strength. Based on the demonstrated compatibility in MUF, DCPD is considered a promising mineral extender of other FRs for application in UF‐based wood composites.

Physicochemical features of the effect of special water-based fire retardants on forest materials

Specialists in forest fire extinguishing consider special fire retardants (solutions, suspensions, and emulsions), in addition to water, to be the promising. When discharged from aircrafts, these agents show greater efficiency in suppressing combustion and preventing ignition of forest materials compared to water. However, such agents have been developed through trial and error so far, because no general theory of the effect of aqueous suspensions, solutions, and emulsions on combustion has been developed yet. In addition, there have not been any experimental data to develop physical and mathematical models of processes when a combustion front acts on forest materials after their wetting by special aqueous compositions. In this paper, we studied the wetting behavior of water and four special fire retardants (bentonite suspension, bischofite solution, fire-extinguishing solution FES-5, and foam agent emulsion) on surfaces of leaves, branches, and needles. The lifetimes and evaporation rates of droplets of fire retardants from the leaf surface were determined at 50–110°С. The differences were established in the evaporation rate of droplets of typical fire retardants and water without additives. With identical initial droplet sizes of fire-extinguishing suspension, emulsion and solutions, their evaporation times differed significantly.

Optimizing Flame Retardancy and Durability of Melamine-Formaldehyde/Solid-Urban-Waste Composite Panels.

In our previous study, an innovative method for sterilization, inertization, and valorization of the organic fraction of municipal solid waste (OFMSW), to be recycled in the production of composite panels, was developed. In this follow-up work, the effects of fire retardants on fire performance, durability, and the mechanical properties of the composite panels based on OFMSW and melamine-formaldehyde resin were investigated. The performance of panels without fire retardants (control panels) was compared to panels containing either mono-ammonium phosphate (PFR) or aluminium trihydrate (ATH) at a mass fraction of 1% and 10% (modified panels). As shown by cone calorimetry, the total heat released was already low (about 31 MJ/m2 at 50 kW/m2) in the control panels, further decreased in the modified panels with the addition of fire retardants, and reached the lowest value (about 1.4 MJ/m2) with 10% mass fraction of PFR. Hence, the addition of fire retardants had a beneficial effect on the response to fire of the panels; however, it also reduced the mechanical properties of the panels as measured by flexural tests. The deterioration of the mechanical properties was particularly obvious in panels containing 10% mass fraction of fire retardants, and they were further degraded by artificial accelerated weathering, carried out by boiling tests. Ultimately, the panels containing PFR at a mass fraction of 1% offered the best balance of fire resistance, durability, and mechanical performance within the formulations investigated in this study.

ИССЛЕДОВАНИЕ ВЛИЯНИЯ ДВУХ ТИПОВ АНТИПИРЕНОВ НА ГОРЮЧЕСТЬ ОБРАЗЦОВ ИЗ ЭПОКСИДНОЙ СМОЛЫ

Studies have been carried out to assess the effectiveness of fire retardants on the flammability of an epoxy composition – graphene and an organophosphorus compound DOPO-THPO. The concentrations of the added flame retardants were 2 and 4 % (mass). Flammability characteristics were determined using the method according to GOST 28157 (UL 94) with vertical and horizontal samples. It was found that the introduction of fire retardants reduces the flammability of the epoxy composition, but the introduction of even 4 % was insufficient to ensure self-extinguishing of the epoxy composition during vertical testing.

IInvestigation of ash wood during treatment with fire-protective agent DSA

Experimental studies of fire-retardant efficacy of DSA for ash wood have been carried out. The dependence of fire-retardant efficiency on the mass of dry agent is obtained, which is important when treating ash wood with DSA. The influence of wood characteristics of different species on the effectiveness of fire-retardant impregnating agents on the example of ash and DSA has been studied. It is established that the standard method of research of fire protection efficiency using only pine cannot provide fair data on the effectiveness of the tool to other wood species. Yes, according to the instructions of the test agent, 3 applications are required, but for ash to achieve the first group of fire-retardant effectiveness required 6 applications. The obtained dependence of the weight loss of the treated wood sample on the amount of fire-retardant composition in standard tests provides the possibility of engineering, economic and other calculations when performing work on fire protection. The standard method of research of fire-retardant efficiency with use of pine exclusively is checked. It is determined that standard test methods cannot be objective when processing species other than pine. Especially useful for the study is the dependence of the weight loss of the treated wood sample on the amount of fire-retardant composition in standard tests, the influence of wood of different species on the effectiveness of fire-retardant impregnating agents such as ash and DSA. The standard method of research of fire-retardant efficiency with use of pine exclusively is checked. Can it be used in the case of ash wood processing. Thus, according to the instructions of the tested tool, 3 applications are required. Ash wood has a higher specific weight than pine, so to make a sufficient amount of active substance is a more difficult task.