Fire-resistant Materials Research Articles

“Rigid-Flexible” structured polyimine/graphite felt composites with excellent fire Resistance, electromagnetic shielding and recyclability

With the development of the electronic information, the conductive polymers with high electromagnetic interference (EMI) shielding effectiveness has become a research point. The polyimine material that forms a cross-linking network can rapidly achieve bond exchange at high temperatures, which is becoming a potential substrate for carbon loaded materials. In this work, a novel composite material is successfully prepared by incorporating cost-effective graphite felt (GF) with excellent electrical properties into a biobased polyimine network. Leveraging the exchange properties of dynamic imine bond (−C = N-), the two substrates can be separated by acidolysis, enabling a recycle of the GF efficiently. The electromagnetic shielding effectiveness (EMI SE) of the composite material in the X-band (8.2–12.4 GHz) reaches approximately 46 dB. Additionally, the introduction of highly fire-resistant graphite material significantly enhances the flame retardancy of the composite by reducing the peak heat release rate (HRR) by 47.1 %, which improves the fire safety in complex electromagnetic environments. Herein, we broaden the application of polyimine/graphite composites in the electronic information field and provide a new strategy for the preparation of environmentally friendly composite materials.

Investigation on novel ultralight weight thermally insulated fireproof composite

Abstract This study highlights the performance of ultra-lightweight fireproof composite. Polyacrylonitrile based carbon fiber (CF) has been reinforced in Polyetherimide (PEI) polymer to develop the composite. The Surfac2e of CF and PEI film was modified by low-pressure plasma to improve the bonding strength between matrix and reinforcement. The polymeric composite was fabricated by compression molding with a pressure of 2 bar, temperature of 380 °C and holding time of 30 min. CF/PEI composite was used to make a hybrid composite by layering of silicone foam in between the layers. The hybrid composite was exposed to a Bunsen burner under sustained flame for a duration of 10 min. The composite panel’s flame-facing side reached 676.2 °C after 10 min of fire exposure, while the temperature on the other side only reached 58.2 °C. The fabricated hybrid composite was exposed to very low temperature in order to test its ability of thermal insulation under extreme cold temperature. Over the specific period of testing, the temperature of the dry ice decreased from 25 °C to −3.1 °C. After exposure to fire, only minimal loss of material was observed. The hybrid composite of carbon fiber and PEK film, sandwiched between silicone foam, exhibits excellent fire resistance due to its high limiting oxygen index. This composite is considered to be among the best thermally insulating and fire-resistant materials. Thermogravimetric analysis of carbon fiber and PEI-Carbon fiber composite was performed to determine the optimal processing temperature of compression molding for the composite, upon heating, it showed a modest weight decrease of 6.053%. The composite shows a significant improvement of impact resistance, compressive strength and thermal stability. A simulation model was developed under Ansys fluent software for both heating and cooling. The analysis of developed model also shows similar results.

Performance of sandwich type fire-resistant flexible composite phase change material PEE@EBF for battery thermal management and runaway protection

To mitigate the risks of overheating and thermal runaway in lithium-ion batteries, this study proposes a novel sandwich-type fire-resistant flexible composite phase change material (CPCM), referred to as PEE@EBF. The core material (PEE) was created by melt-blending paraffin wax (PW), expanded graphite (EG), and ethylene–vinyl acetate copolymer (EVA). The outer layer, a fire-resistant coating (EBF), was applied to the surface of PEE and consists of epoxy resin (EP), boron nitride (BN), and the composite flame retardant (CFR). Test results demonstrated that PEE@EBF maintained structural integrity, exhibiting no significant deformation or leakage after being heated at 80 °C for 5 h. PEE@EBF also displayed a high latent heat of 166.6 J/g, thermal conductivity of 0.8 W/(m∙K), and excellent electrical insulation properties. Furthermore, it achieved a UL94 V-0 flame retardant rating, with notable reductions in peak heat release rate (PHRR) and peak smoke production rate (PSPR) by 67.8 % and 81.8 %, respectively. During long-term cycling at 4C, the peak temperature (PT) and maximum temperature difference (MTD) of batteries in the module incorporating PEE@EBF were reduced by 11.8 °C and 4 °C, respectively, compared to natural convection cooling. In addition, the heat generated during the battery thermal runaway was efficiently absorbed and transferred by PEE@EBF, delaying the irreversible thermal runaway process by 633 s. This indicated that the sandwich-type PEE@EBF was suitable for thermal management and fire protection in lithium-ion batteries or energy storage devices.

Fire prevention and mitigation technologies in high-rise buildings: A bibliometric analysis from 2010 to 2023

PurposeThis study provides a comprehensive bibliometric analysis for research in the area of fire prevention and mitigation in high-rise buildings, an emerging crucial subject. The analysis covers the period between 2010 and 2023, with the main goal of classifying and evaluating the efficacy of fire prevention and mitigation technologies. MethodsThe current study contributes a methodological approach for analyzing fire safety measures and highlighting the critical necessity for multidisciplinary approaches in enhancing fire safety protocols, with a special focus on the integration of advanced fire detection, suppression, and evacuation technologies. The investigation indicates a steady 10 % growth rate in scholarly production on this topic. ResultsResearch on active fire prevention technologies has focused on the technologies including; 1) water mist suppression, 2) unmanned aerial vehicles, 3) Artificial Intelligence (AI) algorithms, and 4) Internet of Things (IoT) frameworks, while research on passive technologies has trended toward fire compartmentation and fire-resistant materials. The study identifies 6 passive technologies and 14 active technologies, with active technologies focusing on water mist suppression, AI algorithms, and IoT frameworks. On the other hand, passive technologies focus on risk assessment, fire protection, and management. ConclusionsThe current study analyzes the role of risk assessment, fire protection, and management in the development of the field of fire mitigation and prevention. The study highlights research collaboration toward reducing risk and fatalities by fire prevention and mitigation solutions. The US and China have the highest collaboration in these technologies, while the UK and the US have the highest publications. Research implicationsThe provided analysis ultimately serves as guidance for stakeholders involved in the design, policy-making, and implementation of fire safety measures in urban high-rise environments, and can give insight on future research direction toward effective strategies and technologies for fire mitigation and prevention in high-rise buildings.

Integrating an urban fire model into an operational wildland fire model to simulate one dimensional wildland–urban interface fires: a parametric study

Background Wildland fires that occur near communities, in the wildland–urban interface (WUI), can inflict significant damage to urban structures. Although computational models are vital in wildfires, they often focus solely on wildland landscapes. Aim We conducted a computational study to investigate WUI fire spread, encompassing both urban and wildland landscapes. Methods We developed a 1D landscape-scale semi-physical model by integrating a semi-physical urban fire spread model into an Eulerian level set model of wildfire. The model includes ignition and spread through radiation, direct flame contact and ember deposition. Key results Through a parametric study, we compare the relative change of spread rate from various structural properties and landscape layouts represented by model parameters, highlighting the significant impact of fire-resistant structure materials over surface treatments. Layout configurations play a pivotal role in fire spread, with isolated islands of combustibles effective in reducing spread rate, aligning with existing mitigation strategies. Conclusion Despite using a 1D domain and limitations on spatial and temporal variability, our model provides insights into underlying phenomena observed in WUI fires and their mitigation. It offers early-stage development of strategies for managing structure materials and landscape layouts. Implications Our model and findings provide insights into WUI fire dynamics, paving the way for advanced mitigation strategies.

Assessing and mitigating building fire risk based on the scenario clusters in Bangladesh

The increasing occurrence of fire hazards in residential buildings in Bangladesh has led to severe property damage, physical injuries, and fatalities, underscoring a critical research gap in effective fire risk management. This study aims to address this gap by identifying key fire risks and proposing mitigation strategies using BIM technology. The research employs a comprehensive survey and scenario clustering methodology to identify these risks and assess the efficacy of various fire-resistant materials. Data collection involved questionnaires distributed to 200 respondents, including building owners, occupants, engineers, and firefighters. These clusters are based on the metrics of fatality numbers and property damage to quantify fire risk. Findings highlight the significant role of wall and ceiling lining materials (RII = 0.919) in contributing to fire risk. Further analysis was conducted using a residential building model developed in Autodesk Revit and simulated in Pyrosim software, assessing various lining materials. Quantitative results demonstrated that fire brick is the most effective material, exhibiting the lowest heat release rate (968 kW/m2), minimum adiabatic surface temperature (28°C), minimum heat transfer coefficient (1.75 W/m2/K), and lowest surface burning rate (7.5e−08 Kg/m2/s). These results suggest that fire brick is the optimal choice for enhancing fire resistance in residential buildings.

Fire performance of CFRP-strengthened piloti-type columns with fire-resistant materials during standard fire exposure

This paper presents a numerical investigation into the fire endurance of carbon fiber reinforced polymer (CFRP)-strengthened columns, shielded with fire-resistant materials, in piloti-type reinforced concrete buildings. The strengthened column, equipped with a fire protection system, underwent exposure to the ASTM E119 standard time-temperature curve for a duration of 4 h. To comprehensively evaluate the thermal and structural performance of the strengthened column at elevated temperatures and substantiate the effectiveness of the fire protection system, a fully coupled thermal-stress analysis was conducted. The numerical modeling approach employed in this study was rigorously validated through previous experimental studies in conjunction with adherence to the ACI design guideline, specifically ACI 440.2R-17. Using the validated structural fire model, the thermal and structural behaviors of the RC column with an insulated CFRP strengthening system were investigated based on four key performance criteria: glass transition temperature, ignition temperature of polymer matrix, critical temperature of reinforcing bars, and the design axial load capacity at elevated temperatures. Furthermore, a comparative assessment of fire endurance was performed using diverse fire-resistant materials, including Sprayed Fire-Resistive Material (SFRM) and Sikacrete®-213 F, with insulation thicknesses ranging from 10 to 30 mm, during the 4-hour fire exposure period.

МОДЕЛЮВАННЯ ВОГНЕЗАХИСТУ СВІТЛОПРОЗОРИХ ФАСАДНИХ КОНСТРУКЦІЙ З ВЛАШТУВАННЯМ ЗРОШУВАЧІВ

The popularity of translucent materials in construction, especially in high-rise buildings, creates challenges for improving approaches to fire safety. Translucent designs have a limited. During a fire, they can quickly heat up, crack or even collapse, which helps the fire to spread to other parts of the building and increases the speed of fire spread. Practical methods and methods of limiting the spread of fire on building facades are considered in the work, including the use of fire eaves, protective screens made of fire-resistant material, limiting the area of the window opening, as well as the use of water irrigation. Water irrigation is an effective method of extinguishing fire and cooling facade elements, but its parameters, such as working pressure, water flow, location, etc., require careful research to achieve maximum efficiency. The purpose of this work is to use the PyroSim software complex to investigate the effectiveness of sprinklers for the protection of transparent structures on the facade of high-rise buildings and to determine their main parameters. With the help of PyroSim, a detailed three-dimensional model was created, which takes into account the complex geometric shapes of the building and the impact of fire protection systems, taking into account the features of translucent facades. In the course of research, structural elements that can affect the spread of fire and smoke are also taken into account, namely the characteristics of materials, fire load, installation of window openings. PyroSim, simulating the spread of a fire, made it possible to take into account heat and smoke flows, convective effects occurring during a fire, as well as the interaction of sprinklers with the heat load. The results of such modeling can be used to optimize the design of fire protection systems and ensure the compliance of building regulations with fire safety issues. In particular, modeling allows you to determine the most effective ways to place sprinklers, taking into account the specific conditions and structural features of the building. Thanks to this, it is possible not only to increase the level of protection of buildings against fires, but also to minimize the costs of installing and maintaining fire systems.

FEATURES OF WASHING WATER-SOLUBLE PHOSPHORUS-AMMONIUM SALTS OF FIREPROOF WOOD COATING

The article analyzes fire-resistant materials for wooden building structures and establishes the need to develop reliable methods of researching the process of washing out flame retardants from the surface of the building structure, which are necessary for the creation of new types of fire-resistant materials. Therefore, there is a need to determine the conditions for the formation of a barrier for leaching and to establish a mechanism for inhibiting the transfer of moisture to the material. In this regard, a mathematical model of flame retardant leaching has been developed, when a polymer shell made of organic material is used as a coating, which allows evaluating the effectiveness of the polymer shell based on the amount of flame retardant washed out. According to experimental data and theoretical dependences, the dynamics of release of flame retardants from the fire-resistant layer of the coating, which does not exceed 1.0%, is calculated, and accordingly provides fire protection of wood. The results of determining the loss of mass of the sample during exposure to water indicate an ambiguous effect of the nature of the protection on leaching. In particular, this assumes the availability of data sufficient for qualitatively carrying out the process of inhibiting moisture diffusion and identifying, on its basis, the moment in time when the decline in coating efficiency begins. Experimental studies have confirmed that a sample of fire-resistant wood after exposure to water for 30 days withstood the influence of heat flow. In particular, the loss of wood mass after temperature exposure was less than 6%, and the temperature of flue gases did not exceed 185 ºС. Thus, there are reasons to assert the possibility of targeted regulation of wood fire protection processes through the use of polymer coatings capable of forming a protective layer on the surface of the fire retardant material, which inhibits the rate of flame retardant leaching.

Microstructure and residual strength properties of engineered geopolymer composites (EGC) subjected to high temperatures

This study investigates the effects of high temperature on the microstructure and residual compressive strength properties of engineered geopolymer composites (EGC). The importance of this study focusses on the performance and durability of EGC, aiming towards sustainable construction practices. The proposed study fills the knowledge gap by the use of steel fibers (SF) as primary reinforcement in EGC, specifically involving a combination of Fly Ash (FA), Basic Oxygen Furnace (BOF) slag, and Iron Ore Tailings (IOT). The residual properties of EGC under high-temperature conditions were assessed by preparing cube specimens (50 mm) involving FA and BOF slag as primary precursors, with IOT as a partial replacement to conventional fine aggregate (M-sand) and brass-coated SF as discrete reinforcement. The specimens were exposed to temperatures up to 1000 °C in a muffle furnace in six different levels: 25, 200, 400, 600, 800, and 1000 °C. Post-exposure, the specimens were ambient cured prior to testing of pore structure distribution, residual strength properties, and microstructural characteristics involving scanning electron microscopy (SEM) analysis. The experimental findings show that, despite various combinations of precursors, IOT and SF, no explosive deterioration or spalling occurred in EGC mixes at any level of exposure. Also, as the exposure temperature increased, the compressive strength decreased while the strain capacity enhanced, denoting an increase in the stiffness of the EGC mixes. Notably, the SF maintained its structural integrity even at 1000 °C, which was consistent with the observed microstructural behavior. This indicates the proposed EGC exhibits excellent resistance to elevated temperatures and enhanced strain-hardening capacity. Overall, this research provides valuable insights into the residual properties and microstructural characteristics of FA: BOF: IOT-based EGC, highlighting its potential as a sustainable and fire-resistant building material. The outcomes contribute significantly to the existing knowledge on EGC and its application in environments exposed to high temperatures.

Effect of Phase Composition Variation of Oxy–Nitride Composite Ceramics on Heat Resistance and Preservation of Strength Parameters

The aim of this study is to determine the effect of changes in the phase composition of Al2O3–Si3N4 ceramics that were obtained using the method of mechanochemical solid-phase grinding on their resistance to the process of long-term thermal exposure, accompanied by the processes of oxidation and softening. The relevance of this research consists of determining the influence of the phase composition of ceramics on the change in their strength and thermophysical parameters, on the basis of which, we can draw a conclusion about the optimal composition of composite ceramics that have great prospects in the field of fire-resistant, heat-resistant, or radiation-resistant structural materials. During this study, the dynamics of the changes in the phase transformations of the xAl2O3–(1−x)Si3N4 ceramics, with variations in the ratio of the components, initiated by the thermal annealing of the samples, was established. According to the assessment of the phase transformations with variations in the ratio of the components, it was found that thermal annealing in an air environment at an Al2O3 concentration in the order of 0.3–0.5 M leads to the formation of an orthorhombic Al2(SiO4)O phase and an elevation in its contribution at concentrations above 0.5 M, which causes a rise in the thermophysical parameters and resistance to high-temperature degradation. During the heat resistance tests, it was found that the formation of the composite ceramics with the Si3N4(SiO2)/Al2(SiO4)O/Al2O3 phase composition results in an increase in the stability of their strength properties when exposed to thermally induced oxidation, which has a negative impact on their resistance to softening and a decrease in hardness. Moreover, the presence of the Al2(SiO4)O phase in the composition of the ceramics causes a slowdown in the processes of thermal oxidation of the Si3N4 phase under prolonged temperature exposure, alongside an increase in the degradation resistance of strength properties by more than 4–7 times, in comparison with the softening data established for single-component ceramics.

Thermal and Combustion Properties of Biomass-Based Flame-Retardant Polyurethane Foams Containing P and N.

Biomass has been widely used due to its environmental friendliness, sustainability, and low toxicity. In this study, aminophosphorylated cellulose (PNC), a biomass flame retardant containing phosphorus and nitrogen, was synthesized by esterification from cellulose and introduced into polyurethane to prepare flame-retardant rigid polyurethane foam. The combustion properties of the PU and PU/PNC composites were studied using the limiting oxygen index (LOI), UL-94, and cone calorimeter (CCT) methods. The thermal degradation behavior of the PU and PU/PNC composites was analyzed by thermogravimetric analysis (TGA) and thermogravimetric infrared spectroscopy (TG-IR). The char layer after combustion was characterized using SEM, Raman, and XPS. The experimental results showed that the introduction of PNC significantly improved the flame-retardant effect and safety of PU/PNC composites. Adding 15 wt% PNC to PU resulted in a vertical burning grade of V-0 and a limiting oxygen index of 23.5%. Compared to the pure sample, the residual char content of PU/PNC15 in a nitrogen atmosphere increased by 181%, and the total heat release (THR) decreased by 56.3%. A Raman analysis of the char layer after CCT combustion revealed that the ID/IG ratio of PU/PNC15 decreased from 4.11 to 3.61, indicating that the flame retardant could increase the stability of the char layer. The TG-IR results showed that PNC diluted the concentration of O2 and combustible gases by releasing inert gases such as CO2. These findings suggest that the developed PU/PNC composites have significant potential for real-world applications, particularly in industries requiring enhanced fire safety, such as construction, transportation, and electronics. The use of PNC provides an eco-friendly alternative to traditional flame retardants. This research paves the way for the development of safer, more sustainable, and environmentally friendly fire-resistant materials for a wide range of applications.

Ensuring fire safety: compliance tests for the use of polystyrene foam in facades systems

Ensuring fire safety is the most important thing in the construction industry, especially when it comes to facade materials. The inherent flammability of polystyrene foam poses significant safety concerns, especially when integrated into facade systems. Therefore, the main focus is on meeting the strict flammability requirements set for construction products, which are assessed by applying rigorous test procedures. This study focuses on the fire resistance testing of a facade system using EPS 70 with graphite additives. The system has been evaluated according to the strict DIN 4102-20 standards. Tests were conducted under real-world conditions to gain insight into the performance of the EPS 70 in real-world fire scenarios. Temperature measurements were taken at various points in the facade system, including at least 3.5 meters above the combustion chamber. The results showed that the temperature does not exceed 500 °C, so it is possible to quantify the thermal properties of the material and the ability to prevent the vertical spread of fire. After the tests, detailed post-test inspections were carried out to evaluate the internal flame propagation after removing the top layer of plaster. The study confirms that polystyrene foam EPS 70 with graphite additives meets the fire safety requirements of DIN 4102-20, which suggests that it can be used more widely in building facades to improve fire safety in residential and commercial buildings. The study highlights the importance of adhering to installation standards, emphasizing the need for accurate installation practices. It also encourages the development of new composite materials with similar or improved fire safety properties, laying the foundation for further innovations in fire-resistant materials

Common incidents and prevention of urban water supply pipeline accidents

With rapid urbanization, urban water supply pipeline accidents have become increasingly prevalent. Understanding their common occurrences and prevention strategies is crucial for ensuring water safety. This study aims to explore the underlying causes of such incidents, ranging from ageing infrastructure to design flaws and construction issues. By analyzing existing preventive measures and international best practices, this research seeks to contribute to the development of effective strategies for mitigating urban water supply pipeline accidents. This thesis focuses on urban water supply pipeline accidents, addressing both common incidents and preventive measures. It begins by highlighting the unique challenges of fires in high-rise buildings, including their rapid spread and the difficulties in evacuating occupants. The paper then emphasizes the importance of innovative fire-resistant materials, classifying them into various types such as phenolic, sprayed, calcium silicate, and lightweight composite materials. Each type is explored in detail, discussing their properties and potential applications. Finally, the paper outlines the practical use of these materials in fire engineering, emphasizing their role in enhancing the safety and resilience of urban infrastructure. Overall, this thesis contributes valuable insights to understanding and mitigating the risks associated with urban water supply pipeline accidents, promoting disaster prevention and management efforts.

Long-term durability of discarded cork-based composites obtained by geopolymerization

Geopolymers are amorphous aluminosilicate inorganic polymers synthesized by alkaline activation characterized by a lower carbon footprint, greater durability, and excellent mechanical properties compared to traditional concrete, making them promising building materials for sustainable construction. To develop sustainable lightweight geopolymer-based building materials useful as fire resistant thermal insulation materials, we added 5 and 10 wt% of discarded cork dust, a readily available industrial by-product, to metakaolin before and after the alkaline activation with sodium hydroxide 8 M and sodium silicate solutions. We followed the chemical, microstructural, antibacterial, and physical properties of the resulting composites for up to 90 days in order to monitor their long-term durability. The presence of cork does not interfere with the geopolymerization process and in fact reduces the density of the composites to values around 2.5 g/cm3, especially when added after alkaline activation. The composites resulted in chemically stable matrices (less than 10 ppm of cations release) and filler (no hazardous compounds released) with a bacterial viability of around 80%. This study provides valuable insights into the tailoring of discarded cork-based composites obtained by geopolymerization with a porosity between 32 and 48% and a mechanical resistance to compression from 15 to 5 MPa, respectively, suggesting their potential as durable interior panels with low environmental impact and desirable performance.

Synthesis of cerium-based flame retardant containing phosphorus and its impact on the flammability of polylactic acid

The synthesis and characterization of [Ce2(PPPA)4(OH)2]·4H2O, wherein PPPA denotes 3-(hydroxy(phenyl)phosphoryl)propanoate, were conducted. Its potential as a flame-retardant additive for poly(L-lactic acid) (PLA) in conjunction with ammonium polyphosphate (APP) was investigated. Remarkably, with just incorporation of the 1 % Ce-complex and 4 % APP, the resulting PLA composite (PLA-8) meets the V-0 standard, exhibiting an impressive limiting oxygen index (LOI) of 29.4 %. Moreover, the introduction of the Ce-complex leads to a significant extension of ignition time (TTI), a significant 24.1 % decrease in total heat release (THR) compared to pure PLA, and a notable increase in residual carbon rate from 0.3 % to 3.51 %. Although PLA-8 exhibits a minor decline of 8.7 % in tensile strength and 3.4 % in elongation at break, respectively, compared to pure PLA, there is a substantial improvement of 32.2 % in Young's modulus and 29.9 % in impact resistance. These results emphasise the potential of cerium-based phosphorus-containing flame retardants, with cerium playing a key role in enhancing the flammability characteristics of PLA. This study contributes to the development of sustainable and fire-resistant materials in polymer chemistry.

REAL TIME WIRELESS FIRE FIGHTING ROBOT

The Real-time Wireless Firefighting Robot is an innovative autonomous robotic system designed for effective fire response in hazardous environments. This robot integrates advanced technologies such as wireless communication, sensors, and real-time data processing to enhance firefighting capabilities. Equipped with a high-resolution camera, the robot can navigate through smoke-filled areas and transmit live video feeds to the control center. The wireless communication system enables seamless remote operation, allowing firefighters to assess the situation and make informed decisions. The robot's robust design and fire-resistant materials ensure its durability in high-temperature environments. Overall, the Live Wireless Firefighting Robot presents a cutting-edge solution for improving firefighting efficiency and reducing risks to human responders. This robot is equipped with advanced sensors for real-time fire detection and localization. Its wireless connectivity enables remote control and monitoring, allowing firefighters to operate it from a safe distance. The robot's mobility and agility enable it to navigate challenging environments, reaching areas that may be hazardous for humans. With a built-in water or foam spraying system, the robot can effectively suppress fires. Additionally, it incorporates live video streaming to provide a comprehensive view of the situation. The use of wireless technology not only facilitates seamless communication but also ensures quick response times, making this robot a valuable asset in firefighting scenarios, minimizing risks to human lives. Key Words: Fire Fighting Robot, Mobility, Live video feeds.

Fire safe and sustainable lightweight materials based on Layer-by-Layer coated keratin fibers from tannery wastes

The increasing consciousness about the depletion of natural resources and the sustainability agenda are the major driving forces to try to reuse and recycle organic materials such as agri-food and industrial wastes. In this context, keratin fibers, as a waste from the tannery industry, represent a great opportunity for the development of green functional materials. In this paper, keratin fibers were surface functionalized using the Layer-by-Layer (LbL) deposition technique and then freeze-dried in order to obtain a lightweight, fire-resistant, and sustainable material. The LbL coating, made with chitosan and carboxymethylated cellulose nanofibers, is fundamental in enabling the formation of a self-sustained structure after freeze-drying. The prepared porous fiber networks (density 100 kg m–3) display a keratin fiber content greater than 95 wt% and can easily self-extinguish the flame during a flammability test in a vertical configuration. In addition, during forced combustion tests (50 kW m–2) the samples exhibited a reduction of 37 % in heat release rate and a reduction of 75 % in smoke production if compared with a commercial polyurethane foam. The results obtained represent an excellent opportunity for the development of fire-safe sustainable materials based on fiber wastes.

Study of a Fire-Resistant Plate Containing Fly Ashes Generated from Municipal Waste Incinerator: Fire and Mechanical Characteristics and Environmental Life Cycle Assessment.

The recycling of fly ash from municipal solid waste incineration is currently a global issue. This work intends to examine the viability of a novel recycling alternative for fly ashes as a component of fire-resistant plates. To lessen the quantity of heavy metal leaching, the fly ash was utilized after being washed using a water/fly ash ratio of 2 for one hour. Subsequently, an inexpensive, straightforward molding and curing process was used to create a plate, with a composition of 60%wt of MSWI-FA, 30%wt of gypsum, 0.5%wt of glass fiber and 9.5%wt of vermiculite. The plate exhibited high fire resistance. Furthermore, it demonstrated compression, flexural strength and surface hardness slightly lower than the requirements of European Standards. This allows for manufacturing plates with a high washed MSWI-FA content as fire protection in firewalls and doors for homes and commercial buildings. A Life Cycle Assessment was carried out. The case study shows that a 60% substitution of gypsum resulted in an environmental impact reduction of 8-48% for all impact categories examined, except four categories impacts (marine eutrophication, human toxicity (cancer), human non-carcinogenic toxicity and water depletion, where it increased between 2 and 718 times), due to the previous washing of MSWI-FA. When these fly ashes are used as a raw material in fire-resistant materials, they may be recycled and offer environmental advantages over more conventional materials like gypsum.

Sorption Processes of Selected PAHs on Selected Fire-Resistant Materials Used in Special Firefighter Clothing.

Fires constitute a significant threat due to the pollutants emitted and the destruction they cause. People who take part in firefighting operations must be equipped with appropriate tools, including special clothing that will allow them to work and guarantee safety. One of the threats is represented by compounds from the PAH (Polycyclic Aromatic Hydrocarbons) group, which are characterized by high toxicity and carcinogenicity. Therefore, it is important that the materials used constitute a barrier to contamination. Various materials from which individual elements of special firefighter's clothing are made were tested. Additionally, the effect of height on the possibility of sorption of PAH compounds on a given type of material was analyzed. Based on the obtained analysis results, it was found that both the type of material and the zone in which the clothing items are used are important in the sorption processes of pollutants. For example, PAHs with high molecular weight are most likely to settle on rubber, i.e., the material from which shoes are made, with the exception of Chrysene, whose presence was found primarily in aramid fibers, i.e., the material from which trousers and jackets are made. However, among PAHs with low molecular weight, compounds such as Methylnaphthalene,1- and Fluorene were sorbed on the rubber surface in large quantities. The only compound that is present in comparable amounts in all materials is Acenaphthylene. Data in this area may be important for taking further actions related to the modification of materials used in special fire brigade clothing and in their cleaning processes.