Fire Retardant Research Articles

Recycling Functional Fillers from Waste Tires for Tailored Polystyrene Composites: Mechanical, Fire Retarding, Electromagnetic Field Shielding, and Acoustic Insulation Properties-A Short Review.

Polymer waste is currently a big and challenging issue throughout the world. Waste tires represent an important source of polymer waste. Therefore, it is highly desirable to recycle functional fillers from waste tires to develop composite materials for advanced applications. The primary theme of this review involves an overview of developing polystyrene (PS) composites using materials from recycled tires as fillers; waste tire recycling in terms of ground tire rubbers, carbon black, and textile fibers; surface treatments of the fillers to optimize various composite properties; and the mechanical, fire retarding, acoustic, and electromagnetic field (EMI) shielding performances of PS composite materials. The development of composite materials from polystyrene and recycled waste tires provides a novel avenue to achieve reductions in carbon emission goals and closed-loop plastic recycling, which is of significance in the development of circular economics and an environmentally friendly society.

A Comparative Analysis of Tannin and Commercial Fire Retardants in Wood Fire Protection

In civil construction, one of the primary challenges associated with wood application is its high flammability and low durability during fires. Although chemical treatment with fire-retardant properties exists, they are expensive and of non-renewable origin. Tannin, a wood extractive, being a phenolic compound, holds promise for enhancing the thermal properties of wood. This study aimed to assess the efficacy of tannin as a fire retardant and compare it with a commercial product, as well as comparing different application techniques for these products. Wood samples from the Simarouba amara Aubl. species were utilized. Tannin and a commercial flame retardant were applied via immersion, vacuum impregnation, brushing, and a treatment of tannin incorporated into water-based wood varnish. Alongside the burning test performance, assessments of the wood’s physical properties, such as colorimetry, thermal stability, and mass retention, were conducted. The application of tannin altered the wood’s color and reduced the spread of fire; its presence significantly reduced the flame duration and maintained the wood’s structural integrity. However, tannin retention was lower compared to commercial flame retardant, leading to reduced fire retardancy. Among the methods tested, immersion proved to be the most effective in enhancing the wood’s resistance to flame contact.

Fire Retardancy of Poly(ethylene 2,5-furandicarboxylate-co-ethylene terephthalate) Regulated by Phosphinate

Fire Retardancy of Poly(ethylene 2,5-furandicarboxylate-<i>co</i>-ethylene terephthalate) Regulated by Phosphinate

Sunflower Stalk ASH: Prime Additive to Latex Paint for Fire Retardancy of Marine Plywood

This research study investigates the use of sunflower stalk ash as a prime additive to latex paint for the fire retardancy of marine plywood. Its main goal was to assess the effectiveness of sunflower stalk ash paint in improving the fire retardancy of marine plywood. The researchers employed a simplified flame spread test to determine the effectiveness of the paint, and statistical analysis alongside observation were used to ascertain the ideal concentration required for the sunflower stalk ash paint. The findings revealed that the use of sunflower stalk ash paint can significantly improve the fire retardancy of marine plywood, with the most effective outcome observed in marine plywood that was coated thrice with 16% concentration of sunflower stalk ash in latex paint. This study suggests that utilizing agricultural waste like sunflower stalk ash could serve as an effective and efficient method for enhancing the fire retardancy of marine plywood.

Cyclodextrin-based host-guest hierarchical fire retardants: Synthesis and novel strategy to endow polylactic acid fire retardancy and UV resistance

β-Cyclodextrin (β-CD) with a cage-like supramolecular structure possesses the hydrophobic internal ring and external hydroxyl groups, which are beneficial for intramolecular interactions known as “host-guest” chemistry. This study presents a β-CD-based three-functions-in-one and host-guest fire retardant (βCD-MOF@Schiff base), which incorporates self-crosslinking Schiff base into its cavity and modification of its surface by metal-organic framework (MOF). With the presence of 5 wt% of βCD-MOF@Schiff base, the LOI value of PLA composites increased to 29 % and showed 15 %, 17 % and 62 % reductions in peak heat release rate (pHRR), total heat release (THR), and the yield of hazard gas carbon monoxide, respectively. The mode action of FR on fire retardation of PLA showed that the FR promoted the char formation with higher thermal stability and graphitization, and modified the decomposition path of PLA. Additionally, the PLA composites exhibited enhanced UV resistance in the UVA and UVB areas with improved UV absorbance and the UPF values improving and doubling. This work develops a new approach to preparing biodegradable FR, which simultaneously endows fire safety and anti-UV properties for PLA.

Research on preparation and performance tests of the fire retardant coatings for special functionalized wires and cables

This study aimed to produce a new potential intumescent flame retardant system through the addition of titanium dioxide and alumina-silica fiber based on optimizing the traditional ammonium polyphosphate (APP) / melamine (MEL) / pentaerythritol (PER) intumescent flame retardant formula. The flame retardant capacity and the physical properties were fully analyzed and discussed. The produced flame retardant coating could resist the rapid rise in 1100 of high flame temperature, whereas 40 exceeded the national standards. Thus, the produced flame retardant coating in this study could be potentially further applied to the cables and wires that are frequently needed in petroleum, telecommunication, military, tunnel, and electric uses.

Glory of Fire Retardants in Li‐Ion Batteries: Could They Be Intrinsically Safer?

Glory of Fire Retardants in Li‐Ion Batteries: Could They Be Intrinsically Safer?

Isomerism-enabling low-temperature ultrasensitive and moisture-resistant fire-alarming “Guarder” via color changing

Aiming to integrate a low-temperature, ultrasensitive and wireless remote-monitoring fire alarming with a fire suppression into a commercialized system, in view of a heat-induced tailored isomerization of Salen molecules and sunflower configuration for a heat capturing, we constructed a quasi-core-shell MAPP@Salen with silaned ammonia polyphosphate guiding a vertical deposition of Salen lamellas assembly. Resultantly, MAPP@Salen demonstrated an ultralow triggering temperature of 120 °C and 1 s time at 250 oC with a remarkable color from yellow to dark red. A Salen isomerization and its vertical alignment on MAPP accounted for an ultra-sensitiveness feature. A model acrylic coating with MAPP@Salen presented a 0.3 s responsive time at 250 °C as well as instant (0.5 s) and unstopped warning once flame approached. A wireless signal communication system via a color recognition algorithm and 4 G IoT was realized. Additionally, the coating provided >10 min and ultrastrong intumescent fire protection via a Salen-participative charring optimization as well as well-persevered structural integrity after a long-term water attack. The fire-alarming capability was retained as well. This work pertaining to a bio-inspired hierarchical assembly integrates a low-temperature ultra-sensitive fire alarming and an optimized fire resistance for commercial all-time-scale fire retardants in multi-scenario universal applications.

Non-solvent displacement nonaqueous precipitation fabrication of novel foldable HAp ceramic paper without fiber and its performance

Novel highly foldable HAp ceramic paper with fire retardancy but without fiber was fabricated via novel non-solvent displacement nonaqueous precipitation strategy. The obtained HAp ceramic paper, characterized by highly smooth and glossy, is characterized via X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), curlability test, moisture absorbency and Pb2+ removal performance test. The results show that the ceramic paper is very straight, uniform, and smooth with high curlability and low moisture absorption. No fiber is detected in the ceramic paper. No defect is either detected except for at the edge area. The HAp ceramic paper is grown along the (002) crystal plane of the hydroxyapatite phase from hexagonal plate like single crystal sheets. The ceramic paper loaded for four times has formed a clear four-layer-structured, with a total thickness of about 832 nm. The thickness of each layer is very uniform, with an average thickness of about 208 nm per layer. HAp ceramic paper has excellent Pb2+ ions removal performance, curling performance, moisture absorption performance and flame retardant performance. These performances confirm this novel HAp ceramic paper has superior properties over the traditional ceramic paper with fibers and shows great application prospect in various fields.

Innovative multifunctional fire retardance of poly(butylene adipate-co-butylene terephthalate)-based bio-composite formulation

Poly(butylene adipate-co-butylene terephthalate) (PBAT), a biodegradable aromatic-aliphatic copolyester, has been widely applied in various fields, but it shows the flammability, resulting in serious fire risk. The flame retardancy of some PBAT/polymer blend systems have been studied, but that of neat PBAT was seldom reported. In particular, the research and development of the bio-based green flame retardant agent is highly desired. In this work, fully bio-derived modified chitosan particles (C-CS), were synthesized and used to prepare a novel PBAT-based multifunctional flame-retardant composite. The PBAT/3%C-CS composite (PC3) exhibited an excellent anti-dripping and self-extinguishing performance and achieved the highest fire safety rating (V-0). Peak of heat release rate and total heat release reduced by 39.8 % and 14.9 %, respectively. The char residue yield of the PC3 increased by 211.6 % in the PC3, compared with that of neat PBAT. Both condensed- and gas-phase played dual roles on increasing the flame-retardant performance of the PC3. The PC3 showed a relatively compact and continuous char layer which acted as a physical barrier to suppress the heat exchange and O2 entry (into the matrix) in the combustion process. Meanwhile, the concentration of O2 and H·/HO· free radicals were diluted by a small portion of non-flammable gas products in the pyrolysis process. Also, the PC3 presented elevated crystallizability and anti-bacterial effect, and reduced UV-transmittance characteristic.

Study of using cork powder as an adjuvant bio-flame retardant in acrylonitrile-butadiene-styrene flame retardant formulations

By having a challenging prospect of developing more environmentally friendly flame-retardant (FR) acrylonitrile-butadiene-styrene (ABS) formulations, an initial study related to the effect of combining ammonium polyphosphate (APP) with cork powder (C), a bio-waste of the cork industry on ABS-FR thermal stability and fire performance is proposed and discussed in the present work. ABS composites with a global filler weight content of 30 wt.% were prepared by using a melt-compounding process. Two different types of thermal decomposition behavior, assessed by means of thermogravimetric analysis (TGA), were observed for ABS/C/APP composites. For formulations with C/APP weight ratio < 1, the thermal decomposition of APP polyphosphate network was shifted to lower temperature. On the other hand, when C/APP ratio was ≥ 1, a new thermal decomposition (TD) step related to an earlier thermal decomposition of cork components was registered between 320 °C and 370 °C. Moreover, by means of Fourier-transform infrared spectroscopy (FTIR) analysis of the pyrolysis gasses, a broader temperature range of ammonia and water release was noticed when APP and C were simultaneously incorporated in ABS. In addition, a micro-scale combustion calorimeter (MCC) analysis revealed that replacing APP by cork led to a decrease of the heat release capacity (HRC) and an increase of the residue formation compared to when only APP was present in ABS composite. Furthermore, forced flaming fire characterization of ABS formulations, studied by means of cone calorimetry (CC), revealed that replacing 20 wt.% of APP by cork (ABS/20C/10APP) led to a similar fire performance to the ABS formulation with 30 wt.% of APP (ABS/30APP). A similar trend under horizontal UL-94 was observed, nevertheless, for the composite with cork in its composition no dripping was noticed. Additionally, by only replacing a 3 wt.% of APP (ABS/3C/27APP) by cork an optimum improvement in fire retardancy was achieved, with the highest efficiency in reducing the peak heat release rate (pHRR) of 21 % regarding ABS/30APP. These results have been related to the chemical interaction between APP and cork components in the condensed phase confirmed by the observance of a more intense P-O-C absorbance peak of the CC residue of ABS/3C/27APP, analyzed by means of FTIR. This composite also showed a more cohesive and expanded char layer, observed by scanning electron microscopy (SEM), which acted as a more efficient protective barrier, reducing heat and mass transfer phenomena during combustion which also led to the highest reduction in linear burning rate (LBR) under horizontal UL-94.

Fully bio‐based flax/furan versus carbon/glass epoxy composites: Scope and limitations in terms of fire and physico‐mechanical performances

AbstractFire and mechanical performances of a bio‐based flax/furan resin composite are evaluated and, in order to assess their commercial potential, compared with those of conventional carbon/glass fiber‐reinforced composites. Fire retardant (FR) variants of flax/furan were obtained by adding FRs to the resin and using (i) flax or (ii) FR‐treated flax fabrics. With (i), the fire hazard of the composite could be reduced to minimum, without detrimental effect on the mechanical properties. However, use of FR‐flax fabric (ii) led to impairment of mechanical properties. This indicated that for optimized fire and mechanical properties, use of a FR in the resin matrix suffices; there is no advantage in using a FR‐treated flax fabric. Natural aging of the samples for 10 years followed by water aging indicated that water absorption in flax/furan composites was much higher than in comparable carbon/epoxy composites. While there was evidence of released acidic components such as acetic acid, oxalic acid, and so forth, in flax/furan composites, mainly from oxidative degradation of furan resin, there was no evidence of leaching of FR additives from the matrix. However, FR treatment of flax fabric affected the fiber–matrix interfacial adhesion, leading to considerable water absorption during aging and disintegration of the reinforcement.Highlights Furan resins are naturally fire retardant, burn only under forced combustion. FR flax/furan composites obtained by adding FRs to the resin or the flax fabric. FR treatment of the flax impairs mechanical properties and water tolerance. FRs in the resin neither affect mechanical properties nor leach out in water.

Polybutylene adipate terephthalate (PBAT) composites for thermally conductive, fire retardant, high dielectric applications using BaTiO3 and MWCNTs as fillers

This study provides a comprehensive investigation of the fabrication of novel composite materials by blending polybutylene adipate terephthalate (PBAT) with barium titanate (BaTiO3) and multiwalled carbon nanotube (MWCNT) fillers. Prior to fabricating the composites, the filler surface treatments were tailored to enhance their compatibility with the PBAT matrix. Adipic acid (AA), a monomer for PBAT, was employed on the surface of the BaTiO3 particles, while butanediol (BD) also a monomer of PBAT was used to modify the surface of the MWCNTs to ensure effective interaction with the PBAT chains during the composite fabrication process. The composite samples were produced by melt-blending at 140 °C, followed by injection molding at the same operating temperature for subsequent analysis. The results revealed remarkable improvements in the dielectric constant, thermal conductivity, fire retardancy, and tensile strength of the 40 wt% BaTiO3 and MWCNT-PBAT blends compared to pure PBAT. The incorporation of BaTiO3 additionally contributed to enhanced fire retardancy, mechanical properties, and dielectric properties, making the composite material more resistant to ignition and flame spread, thus rendering it suitable for applications requiring elevated fire safety. In addition, the inclusion of MWCNT improved thermal conductivity, enabling promising and efficient heat dissipation in various applications.

High-amylose starch-based gel as green adhesive for plywood: Adhesive property, water-resistance, and flame-retardancy

The escalating demand for environmentally sustainable and cost-effective adhesives in the wood processing and manufacturing sector has prompted exploration into innovative solutions. This study introduces a novel gel adhesive composed of chemically unmodified high-amylose starch (G70, with 68 % amylose content) with a minimal proportion of urea-formaldehyde (UF) (UF/starch = 1:10, w/w). This G70/UF gel demonstrates remarkable adhesive capabilities for wooden boards under both dry conditions (with a shear stress of 4.13 ± 0.12 MPa) and wet conditions (with a shear strength of 0.93 ± 0.07 MPa after 2 h of water soaking). The study unveils that the elevated amylose content in the starch, coupled with a meticulously controlled isothermal process during bonding, is crucial for these enhancements. Specifically, the robust cohesion of amylose chains expedites phase separation between starch and UF, while the isothermal process facilitates the migration and enrichment of UF molecules at the gel-board and gel-air interfaces. Lacking these mechanisms, conventional amylopectin-rich starch/UF gels (27 % amylose content) show minimal improvement. Moreover, the G70/UF gel showcases exceptional fire retardancy. In all, the G70/UF gel presents a promising alternative for plywood production, reducing reliance on unhealthy UF resin while offering satisfactory bonding resistance in diverse conditions and superior flame retardancy.

Advancing building fire safety through heat resistant and flame retardant hybrid silicone sealant

Rapid urbanization and population growth have led to a significant transformation in the urban landscape, characterized by the proliferation of high-rise buildings. However, this urban development has brought about new challenges, particularly in terms of fire safety. The escalating risk of disasters, especially fires, underscores the critical importance of implementing effective fire safety measures across all building types, necessitating legislative reforms. Despite their crucial role in ensuring structural integrity, sealants have often been overlooked in building safety standards, resulting in a lack of comprehensive regulations. The research addresses these challenges by focusing on the development of fire-resistant silicone sealants designed to enhance the fire resistance of building materials. These sealants were formulated independently, incorporating three fire retardants and four heat-resistant agents. While metal oxide flame retardants generally exhibited excellent performance, excessive mixing led to surface deformation and reduced workability. Optimal combinations of flame retardants and heat-resistant agents were identified, with the FR2 specimen demonstrating promising fire resistance performance. Full-scale fire performance tests conducted on FR2 revealed a maximum temperature difference of 40.6 °C between heated and unheated surfaces over a 2-h period, indicating high thermal insulation performance. These findings validate the efficacy of the proposed method and offer significant enhancements to building safety, thereby mitigating fire damage in urban environments.

Cellulose-based eutectogel electrolyte with high ionic conductivity for solid-state lithium-ion batteries

It is known that the low ionic conductivity of solid-state polymer electrolytes at room temperature (RT) has severely restricted their practical application in lithium-ion batteries. Although eutectogel (ETG) electrolytes could solve this problem to some extent, highly compatible deep eutectic solvent (DES)/polymer systems are desirable to further enhance ion conduction. Herein, we designed cellulose-based ETG (CETG) with dual channels through “hopping” and “vehicle” mechanisms by hydroxyethyl cellulose (HEC) molecular chains and N-methylacetamide (NMA)/LiTFSI-derived DES, respectively. Thanks to the strong molecular interactions between HEC and DES, the highest DES content in the ETG could achieve 90 %, which endowed the CETG with an excellent ionic conductivity of 2.04 × 10–3 S cm−1 at 30 °C. Additionally, our designed CETG displayed good self-healing and fire retardant properties. The assembled Li/LiFePO4 cell showed a capacity retention of 91.8 % after 200 cycles at 0.2 C under RT with an initial discharge capacity of 156.2 mAh g−1. In particular, the capacity retention rates of the assembled batteries reached 95.2 % and 92.1 %, respectively, after 100 cycles at 0.2 C under 60 °C and 50 cycles at 0.2 C under 100 °C. Our fabrication strategy would provide a novel idea for the design of green, safe and efficient solid-state polymer electrolytes for lithium-ion batteries.

A Review and Thermal Conductivity Experimental Program of Mattress Waste Material as Insulation in Building and Construction Systems

The building and construction industry consumes a significant amount of natural resources alongside contributing to the generation of waste materials. Addressing the dual challenge of waste management and recycling in this sector is imperative. This study begins with a bibliometric assessment to identify waste materials used as insulation in building and construction systems. The assessment of 2627 publications revealed mattress waste materials were seldom considered. The aim of this research focuses on exploring alternative methods for repurposing mattress materials in construction, aiming to mitigate waste generation. While various materials are being recycled for building applications, this research emphasises the potential of incorporating recycled polyurethane foam (PUF) from mattresses as insulation products. A transient plane source (TPS) was employed to determine the thermal conductivity of waste mattress PUF obtained from a recycling plant in Victoria, Australia. The results exhibited promising thermal resistance, with a mean value of 0.053 Wm/K. However, optimal thermal performance was observed with increased thickness, suggesting that a thickness of 215mm aligns with industry standards for building fabric systems. Further research is required to comprehensively analyse moisture resistance and fire retardation of waste mattress materials. This paper presents key findings of current trends, limitations, and future research directions to the use of waste mattress PUF as an insulation material.

Perfluoroalkyl sulfonate induces cardiomyocyte apoptosis via endoplasmic reticulum stress activation and autophagy flux inhibition

Perfluoroalkyl sulfonate (PFOS) is a commonly used chemical compound that often found in materials such as waterproofing agents, food packaging, and fire retardants. Known for its stability and persistence in the environment, PFOS can enter the human body through various pathways, including water and the food chain, raising concerns about its potential harm to human health. Previous studies have suggested a cardiac toxicity of PFOS, but the specific cellular mechanisms remained unclear. Here, by using AC16 cardiomyocyte as a model to investigate the molecular mechanisms potential the cardiac toxicity of PFOS. Our findings revealed that PFOS exposure reduced cell viability and induces apoptosis in human cardiomyocyte. Proteomic analysis and molecular biological techniques showed that the Endoplasmic Reticulum (ER) stress-related pathways were activated, while the cellular autophagy flux was inhibited in PFOS-exposed cells. Subsequently, we employed strategies such as autophagy activation and ER stress inhibition to alleviate the PFOS-induced apoptosis in AC16 cells. These results collectively suggest that PFOS-induced ER stress activation and autophagy flux inhibition contribute to cardiomyocyte apoptosis, providing new insights into the mechanisms of PFOS-induced cardiomyocyte toxicity.

Effect of graphene on properties of acrylic emulsion intumescent fire retardant coating

Nowadays, intumescent paint is one of the most popular fireproof paint products and is widely used in buildings. They can be applied to steel, wood, concrete, etc. This study aimed to enhance the properties of intumescent coating by graphene addition. The effect of graphene (GR) content on fire resistance, thermal and mechanical properties of water-based intumescent coatings were studied. Intumescent coating formulations include acrylic emulsion binder (R4152), flame retardant additives (Ammonium polyphosphate (APP) - acid source, pentaerythritol (PER) - carbon source, melamine (MEL) - foaming source), fire retardant fillers (TiO2, Al(OH)3) were prepared by mixing different graphene content (0.5, 1, 1.5 and 2 wt.% GR). The investigated coating properties were examined by fire protection test, furnace test, static water immersion test, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and mechanical properties (adhesion, pendulum hardness). The results showed that the GR could effectively enhance the fire resistance performance (from 13.6 % to 23.4 %), thermal stability (from 2.9 % to 5.2 %), water resistance (from 5.0 % to 11.9 %), and mechanical properties (from 5 % to 12 %) of the coating.

Thermal degradation and fire retardant behaviour of natural fibre reinforced polymeric composites- A comprehensive review

In this comprehensive review, we dive into the potential of natural fibre composites, tracing their historical use spanning three millennia and their recent incorporation into polymer matrices. Various natural fibres, including flax, hemp, jute, and more, have been explored as potential reinforcements due to their renewable nature and environmental appeal. Moreover, these fibers are gaining traction in industries such as automotive and packaging. Leveraging abundant agricultural waste such as, wheat husk, rice husk, straw, and hemp fibre into commercially viable fibre-reinforced polymer composites. A thorough summary is given in this article of the diverse array of natural fibers, their current research status, encompassing properties, processing techniques, filler materials on structural factors, thermogravimetric analysis, dynamic mechanical performance under thermal loading, fire retardant behaviour, cone calorimetric analysis and various other applications, all while referencing the latest developments in the field, exploring a sustainable future with natural fibre composites. Furthermore, the difficulties associated with natural fibre-reinforced composites, including their vulnerability to humidity, fire retardancy and compliance with fibre matrices, are examined. This paper summarizes the complex field of natural fibre composites and covers several thermal stability-related appearance.