Fireproof Materials Research Articles

Evolution Process of Fault Silica Aerogel under High Temperatures: A Molecular Dynamics Approach.

Building fire will seriously threaten human safety. Silica aerogel with low thermal conductivity and thermal stability as fire-retardant material has been widely used in building fireproof structures. However, the natural fragility of silica aerogel will limit its application. In this work, the effects of faults on the thermal stability of silica aerogel are studied by molecular dynamics simulation with large simulation time (20 ns). Additionally, the atomic model of silica aerogel with random faults is built by a straining structure (tensile strains are 10%, 20%, 30%, and 40%). It is found that when the tensile strain is less than 20%, the silica backbone can remain stable. The effects of faults on the thermal stability can be neglected. The silica backbone thermally vibrates during the heating process. However, when the tensile strain is over 30%, it is observed that the faults will enhance the silica backbone merging. Silica aerogel can be stable under 800 K. It is believed that the results of this study will pave the way for the development of fireproof materials.

Preparation and performance verification of calcium silicate composite electrical fireproof materials

Preparation and performance verification of calcium silicate composite electrical fireproof materials

Oil and Gas Structures: Forecasting the Fire Resistance of Steel Structures with Fire Protection under Hydrocarbon Fire Conditions

The hydrocarbon temperature–time curve is widely used instead of the standard curve to describe the temperature in the environment of structural surfaces exposed to fire in oil and gas chemical facilities and tunnels. This paper presents calculations of the ratio of time to reach critical temperatures at different nominal fire curves for steel structures such as bulkheads and columns with different types of fireproofing. The thermophysical properties of the fireproofing materials were obtained by solving the inverse heat conduction problem using computer simulation. It was found that the time interval for reaching critical temperatures in structures with different types of fireproofing in a hydrocarbon fire decreased, on average, by a factor of 1.2–1.7 compared to the results of standard fire tests. For example, for decks and bulkheads with mineral wool fireproofing, the K-factor of the ratio of the time for reaching the critical temperature of steel under the standard curve to the hydrocarbon curve was 1.30–1.62; for plaster, it was 1.56; for cement boards, it was 1.34; for non-combustible coatings, it was 1.38–2.0; and, for epoxy paints, it was 1.71. The recommended values of the K-factor for fire resistance up to 180 min (incl.) were 1.7 and, after 180 min, 1.2. The obtained dependencies would allow fireproofing manufacturers to predict the insulation thickness for expensive hydrocarbon fire experiments if the results of fire tests under standard (cellulosic) conditions are known.

Structural properties and barrier performance of low-cost aerogel composites for building insulation

The high cost and weak mechanical properties of silica-based aerogel seriously affect its wide application in the field of building insulation. In this paper, low-cost SiO2 aerogel (WSA) was prepared based on water glass/water system, and the modulation of aerogel network structure was achieved under the dual effect of sodium methylsilicate (SMS) and pH. WSA exhibits extremely low density (∼88.5 kg/m3) and thermal conductivity (0.02114 W/(m·K)) as well as high hydrophobicity (150°). The cost of WSA is 53 % lower compared to atmospheric pressure drying and 21.5 % lower than commercial aerogel. On this basis, rock wool fiber felt (RWF) and ultrafine glass fiber wool felt (UGFW) were modified with WSA. The effect of fiber arrangement on the force-thermal coupling property of WSA@RWF was investigated. Meanwhile, the addition of WSA reduced the volumetric water absorption of RWF by 85.1 % and 91.4 %. Since the sandwich structure, the thermal conductivity of WSA@UGFW can be as low as 0.01168 W/(m·W), which is 44.7 % and 44.4 % lower than that of UGFW and WSA. It features a low density of 45.7 kg/m3 and a high hydrophobicity angle of 155.87°. In addition, the compressive strength of WSA@UGFW is increased by 16.5 times. Therefore, the aerogel materials prepared in this paper have great application potential as fire-proof building insulation materials.

A REVIEW ON LIGHT WEIGHT, BULLET PROOF AND FIRE PROOF MATERIALS FOR DEFENSE SECTOR: Existing and Succeeding Developments

A REVIEW ON LIGHT WEIGHT, BULLET PROOF AND FIRE PROOF MATERIALS FOR DEFENSE SECTOR: Existing and Succeeding Developments

Adjustable Ti2C3Alx-based segregated composite network for enhanced electromagnetic shielding and fire safety

With the rapid development of communication technology and portable electronic devices, the demand for the design of electronic devices with superior electromagnetic interference shielding and fire safety performance is increasing. Herein, epoxy resins (EPs) with typical segregated networks were designed by emulsion polymerization and adhesion self-assembly strategies and novel polyphosphonitrile microspheres (PZS) synthesized by precipitation polymerization were used to improve the fire safety of EP composites. It is worth noting that the oil-water (EP to water) ratio in emulsion polymerization is closely related to the microscopic morphology of the segregated network. A smaller ratio of EP to water results in more paths for electrical charge transfer through the EP composites. As a result, EP/PT-3 with a minimum oil-to-water ratio exhibits a high EMI SE (electromagnetic interference shielding effectiveness) in the X-band ranging from 40.12 to 40.30 dB at a loading of 7.20 vol% Ti3C2Alx. Besides, the synergistic action of the adjustable Ti3C2Alx network with PZS endows EP superior flame retardant performance. Compared with EP, the PHRR and THR values of EP/PT-3 are down 55.7 % and 72.6 %, respectively. There is no doubt that EP/PT-3 has provided a new route for the preparation of Ti3C2Alx-based electromagnetic shielding and fireproof materials.

Research on the application of ultrasonic pulse velocity method in fire-damaged concrete

The number of fires that break out in buildings accounts for most of all fires worldwide. People are very concerned about the damage to the concrete structure after the fire because the safety of the fire-damaged concrete structure needs to be assessed. The Ultrasonic Pulse Velocity Method is most frequently employed in the non-destructive evaluation of fire-damaged concrete. The UPV method has been widely used in the concrete industry for over fifty years. It is an essential non-destructive technique because it uses relatively inexpensive equipment and can provide reliable results quickly. This paper summarizes the traditional methods of using UPV in fire-damaged concrete, the application of UPV in new fireproof materials, and the use of UPV on other potential test objects. Whats more, this paper also provides suggestions for the future development of UPV testing, so as to improve the repair and evaluation efficiency of fire-damaged concrete structures.

Agent-based modeling of high-rise building fires reveals self-rescue behaviors and better fire protection designs

It is always challenging to seek external rescue assistance in high-rise building fires. Therefore, it is critical for individuals to master survival skills. For crowd dynamics modeling, previous research focused on numerical simulations and building designs with little attention to the self-rescue mechanism. It is critical to understanding crowd evacuations and better response strategies. We modeled the Grenfell Tower (a high-rise building with a complicated structure) case in 2017. Based on the percolation and social force models, we build an agent-based model to simulate individual behaviors inside. We obtain the optimal solution and robust paralleled outcomes under all counterfactual situations based on precisely matching tangible case outcomes (fire duration, deaths, and injuries). For individuals, mastering self-rescue skills is better at reducing social losses (deaths & injuries). In terms of high-rise buildings design, the central alarm system is also useful to reduce them. Besides, the crowd evacuation guided by the social force model also reduces deaths & injuries. This work provides insight into better high-rise building design and practical response strategies for societies. The central alarm system and fire-proof materials should be used in high-rise buildings. The residents should have routine training in social force-based evacuations and survival (self-rescue) skills to better the evacuation process and outcome under natural disasters and social emergencies.

Pyrolysis characteristics, reaction mechanisms and gas emission of organic fireproof plugging materials by TG-FTIR-MS

Pyrolysis characteristics, reaction mechanisms and gas emission of organic fireproof plugging materials by TG-FTIR-MS

Thermal degradation and flame spread characteristics of epoxy polymer composites incorporating mycelium

Although bioderived flame retardants are environmentally sustainable and less toxic, their impact on the thermal stability and flammability of polymers remains poorly understood. In this study, we assessed the influence of mycelium on the thermal stability and flame spread characteristics of epoxy through thermogravimetric analysis, Fourier transform infrared spectroscopy, the UL94 flammability test, and scanning electron microscopy. We observed a decrease in the maximum mass loss rate temperature when mycelium was incorporated into epoxy, indicating an earlier onset of thermal degradation. The inclusion of mycelium increased char yields above 418 °C due to mycelium’s inherent char-forming ability. However, mycelium did not alter the thermal degradation pathway of epoxy. Furthermore, according to the UL94 test results, the incorporation of mycelium reduced the flame spread rate compared to that of neat epoxy. These findings contribute to our understanding of the interaction between bioderived flame retardants and polymers paving the way for the development of more sustainable fireproofing materials.

Sustainable biomass-based composite biofilm: Sodium alginate, TEMPO-oxidized chitin nanocrystals, and MXene nanosheets for fire-resistant materials and next-generation sensors

Efficient utilization of natural biomass for the development of fireproof materials and next-generation sensors faces various challenges in the field of fire safety and prevention. In this study, renewable sodium alginate (SA), TEMPO-oxidized chitin nanocrystals (TOChNs), and MXene nanosheets were employed to fabricate a sustainable, flexible, and flame-retardant composite biofilm, donated as STM, utilizing a simple and environmentally friendly evaporation-induced self-assembly technique. The incorporation of SA, TOChNs, and MXene in a weight ratio of 50/10/40 led to improved mechanical properties of the resulting STM-40 films, as evidenced by increased tensile strength and Young's modulus values of approximately 36 MPa and 4 GPa, respectively. Notably, these values were approximately 3 and 11 times higher than those observed for the pure SA film. Moreover, the STM-40 films demonstrated highly sensitive fire alarm capabilities, exhibiting a superior flame alarm response time of 0.6 s and a continuous alarm time of approximately 492 s when exposed to flames. The STM exhibited exceptional flame retardancy due to the synergistic carbonization between MXene and SA/TOChNs, resulting in a limiting oxygen index of 45.0 %. Furthermore, its maximum heat release rate decreased by over 90.1 % during the test. This study presents a novel approach for designing and developing fire-retardant fire alarm sensors by utilizing natural biomass.

Sintering behavior of ceramic ethylene‐propylene‐diene rubber/pyrophyllite/zinc borate composites

AbstractCeramic polymer materials have great future applications in the field of fireproof materials. However, ceramic polyolefins have shortcomings such as few available inorganic fillers, high sintering temperature, and low flexural strength. Therefore, achieving rapid sintering of ceramic ethylene‐propylene‐diene rubber (EPDM) is an urgent problem that needs to be solved. Herein, we prepared ceramic EPDM materials using pyrophyllite as aggregate and zinc borate as flux. The materials were prepared using a mixer and sintered in a muffle furnace at 850 and 1000°C. The flexural strength of the sinter residue was tested by a material testing machine. The microstructure changes during the ceramification process were characterized using scanning electron microscopy (SEM), thermogravimetric analysis (TG), derivative thermogravimetric analysis (DTG), differential thermal analysis (DTA), and x‐ray diffraction (XRD). The results indicated that the EPDM filled with pyrophyllite and zinc borate had a flexural strength of 2.6 MPa after sintering at 850°C. After sintering at 1000°C, its flexural strength further increased up to 12.3 MPa. The SEM results indicated that as the temperature increased, the zinc borate melted and filled in the space among pyrophyllite particles, and the zinc borate and the pyrophyllite were sintered into a dense whole. The TG, DTG and DTA testing results indicated that the melting and decomposition behaviors of the pyrophyllite‐zinc borate mixture changed compared with pure pyrophyllite and zinc borate. The XRD results indicated that during the sintering process, the crystalline structure of the zinc borate and the pyrophyllite gradually transformed into a quartz‐based crystalline structure. It is promising that the ceramic polyolefin materials are prepared by the pyrophyllite/zinc borate combination.

Влияние фосфорсодержащих антипиренов на показатели пожарной опасности газонаполненных полимеров на основе реакционноспособных олигомеров

Introduc tion. The reduction of flammability of gas-filled polymers prone to carbonization is based on the use of phosphorus- and boron-containing compounds that reduce the formation of combustible volatile pyrolysis products and increase the yield of coke residue. This reduces the rate of heat release, heat and mass transfer between the material and the flame. In the scientific literature the data about the influence of phosphorus-containing flame retardants on thermal stability, combustibility and smokeability of foams are given, but there are no data about the influence of phosphorus concentration on fire danger indicators of foams. The aim of this paper is the development of effective methods of production of casting foams based on reactive oligomers with low fire hazard and high-performance. Objectives: to reveal the influence of phosphorus concentration on the technological and physical-mechanical characteristics, thermal resistance and fire hazard indices of foams and to develop fire-proof thermal insulation materials possessing high performance. Methods. Physical-mechanical properties and fire hazard indices of gas-filled polymers were determined according to current GOST. Thermal properties and composition of combustion products of foams have been studied with thermoanalytical complex DuPONT-9900 and chromatography-mass spectrometry. Results and discussion. The concentration of phosphorus in the synthesis of rigid polyurethane foams with reduced flammability and high performance should exceed 2.1 % wt. The low-combustible urea foams have been obtained at a phosphorus concentration of 0.2–0.3 % wt. For the production of non-flammable, low-­flammable resin foams, the phosphorus concentration is 0.6–0.7 % wt. At the same time, organophosphorus flame retardants containing reactive groups are highly effective. Conclusion s. As a result of experimental studies the influence of phosphorus concentration and content of organophosphorus-containing flame retardants on physical-mechanical properties, thermal stability and fire hazard of foams based on reactive oligomers was revealed, the pouring foams with lowered fire hazard and high performance were developed.

Long-term phase composition and microstructure characteristics of phosphoric acid modified magnesium oxychloride cement exposed to natural environment

Magnesium oxychloride cement (MOC) is widely used as fireproof materials, decorative materials, and adsorption materials, etc. However, its poor water resistance limits the engineering application as a building material. The existing researches mainly focus on improving the short-term durability and water resistance, but few focus on long-term durability of MOC. In this paper, phosphoric acid-modified MOC samples with an age of 2–16 years from China and the Netherlands were collected. Their phase composition and microstructure characteristics were studied, which is of practical engineering significance for the modification of MOC. The results indicate that MOC modified by phosphoric acid would be decomposed and carbonated, and water in the ambient where MOC exposed to is the main factor. MOC exposed to humid environment presents a loose and porous morphology, but shows dense matrix with drying shrinkage cracks in dry air condition. MOC exposed to the air shows good carbon capture ability. The carbonated wood-MOC shows lower porosity than fresh wood-MOC paste. Carbonation phase on the surface of MOC products is beneficial to the internal structure and stability of MOC matrix. Besides, MOC is an environmentally friendly material. The manufacture of MOC requires less energy compared to ordinary Portland cement and shows good carbon neutralization potential under service life.

Impact of Accelerated Weathering on Fire Resistance Performance of Intumescent Materials

The fire resistance performance of intumescent fireproofing materials for steel structure changes with time, as a result of exposure to environmental conditions especially temperature. The objective of this study is to investigate the impact of environmental conditions on fire protection properties (fire performance and char formation) of intumescent coating materials by using accelerated weathering technique. In this study a group of eight steel plates were coated with intumescent fireproofing of the same dry film thickness (DFT), the prepared samples were devided into two supgroups in which every supgroup of four specimens was exposed to ultraviolet radiation (UV) of wavelength (340 nm) for 0, 3, 6 and 9 years. The all intumescent coated samples were exposed to fire resistance tests in accordance with International test standard to evaluate their fire resistance performance. The formed char layers were characterized by using scanning electron microscopy (SEM). The results revealed insignificant change in the fire resistance for the 3 years aged samples. Increasing the accelerating aging over 3 years led to remarkable degradation of fire resistance. The SEM analysis revealed various foaming efficiencies as function of the exposure time.

Fe3O4 and Ag micro/nano coating for high-efficiency flame retardancy and electromagnetic interference shielding

In order to solve the growing problem of electromagnetic radiation and accidental fires due to heat accumulation or electric heating smart clothing, electromagnetic shielding materials with fire resistance are urgently needed. Herein, a polydopamine-assisted polysulfonamide (PSA) nonwoven fabric was designed as a hydrophilic substrate and nano‑silver was employed as a conductive layer. A mixed solution of Fe3O4 with ammonium polyphosphate (APP) was further treated to obtain the surface of microspheres with incombustibility. Interestingly, the micro-nano electromagnetic wave loss gradient enabled the PSA/Ag/Fe3O4/APP-1(PSA/AFA-1) fabric to exhibit efficient absorption-dominant electromagnetic shielding performance, and the optimized fabric exhibited an EMI SE value of 45.5 dB at X-band (8.2–12.4 GHz) with a shielding efficiency of 99.99 %, which remained stable under multiple twisting and bending. This study opens up a new idea for the preparation of fireproof EMI shielding materials with broad application prospects as well as next-generation multi-purpose garments.

Study on the performances of fire-resistive engineered cementitious composites (ECCs)

The high ductility of fire-resistive engineered cementitious composites (ECC) makes it possess better cohesive performance than the traditional cement-based fireproof material, and improves the cracking and delamination between the fireproof material and the substrate material. In this paper, the tensile and compression properties, dry density, heat insulation properties, and high temperature resistance of the prepared fire-resistive ECC materials were systematically studied, and the heat transfer behavior in the heating process was studied by means of small-scale fire resistance test. The results demonstrate that the prepared fire-resistive ECC materials possess both the favorable thermal insulation properties and adequate mechanical properties. Meanwhile, compared with traditional cementitious fireproof materials, better high temperature stability of prepared fire-resistive ECC avoids the failure due to the deterioration of mechanical properties during heating process. Then the reduction of temperature rising rate and equilibrium temperature shown in small-scale fire resistance experiments verifies that it can effectively improve the fire performance of the structure under actual fire. Finally, with the help of microscopic experiments the action mechanism of the porous fillers on the ductility and fire performance of fire-resistive ECC materials were explored.

Research, test and evaluate fireproof materials for mixed solid fuels operating reliably in the temperature range -50÷50oC

This article presents experiment results on the manufacture of the flame retardant sheath for the based-rubber solid fuel bar-nitrile butadiene rubber NBR26. The flame retardant sheath is specified by high mechanical strength (tensile strength 19.2 MPa), good solvent resistance (swelling capacity in toluene 19.5%), good heat and cold resistance ensuring the working capability of the mixed solid fuel bar in the temperature range (-50÷50oC). The product’s calorific effect is high (over 3000oC) during the period of up to 12 s according to the design document. The results of this experiment play an important role in the development of the rocket industry in general and the mixed rocket solid fuel industry in particular in Vietnam in the next period.

Review and prospects of research on materials to prevent and extinguish mine fires

AbstractCoal spontaneous combustion (CSC) has hindered the utilization of coal resources and the development of the global economy for centuries. At present, many materials are used for preventing and extinguishing CSC fires, and different types of materials have various sites of action. In this paper, research on CSC fire prevention and extinguishing materials is reviewed and proposed. The preparation schemes and effects of physical barrier materials, chemical inhibitors, composite materials, and other fields of fire prevention materials were discussed. The improved compounding schemes of CSC inhibiting materials were analyzed regarding the characteristics of base materials and material properties. It was found that in the field of fire prevention materials, plant extracts, hydrolyzed proteins, biomass, and other green recycling materials have gradually become the new trend in materials. The composite material has a synergistic physical barrier and chemical inhibition and has a good inhibitory effect on coal heat storage and group activation, which has become an inhibitory material that is highly concerning. CSC inhibiting technology involving microbial control has emerged and exhibits notable characteristics, including a green cycle and long action time, but its application still needs to control the coexistence of heterogeneous microorganisms and improve the environmental livability. High‐quality firefighting materials, which are used in preventing battery fires, fighting building fires, inert coatings of cotton fabric, and other fields, have potential applicational value for CSC prevention. This review aims to provide new ideas for the research of CSC fireproof materials.

Facile synthesis of intrinsically flame‐retardant epoxy thermosets with high mechanical properties from lignin derivatives

AbstractPreparing bio‐based epoxy resins with high performance is crucial to sustainable development. However, seeking renewable and flame‐retardant epoxy resins with high mechanical properties are still challenging. Here, we reported a facile way to transform lignin derivatives to intrinsic flame‐retardant epoxy resins with satisfactory mechanical properties. Two guaiacol‐based novolac epoxy resins (i.e., GTEP/DDM and GPEP/DDM) were prepared as alternatives for petroleum‐based DGEBA/DDM. The cured GTEP/DDM product showed a high Tg of 209.5°C, a high tensile modulus of 3.13 GPa, and a high LOI of 28.6% with UL‐94 V‐1 rating, which outperformed DGEBA/DDM system. Specially, GPEP/DDM resin possessed more superior mechanical properties (e.g., tensile strength of 73.9 MPa, and tensile modulus of 5.85 GPa) owing to additional interactions (i.e., π–π interactions and hydrogen bonds), and outstanding anti‐flammability (e.g., LOI of 31.2% with UL‐94 V‐0 rating) due to the endow of phosphorus‐containing groups. The mechanical reinforcement and flame‐retardant mechanisms were clarified based on structural evolution and performance variation. This work provides an efficient synthesis route to achieve a high‐performance thermoset, which is a promising alternative for substituting conventional bisphenol‐A epoxy resin for use as fireproof materials.