Flame Retardant Properties Research Articles

Development of sustainable flame-retardant bio-based hydrogel composites from hemp/wool nonwovens with chitosan-banana sap hydrogel

Flame retardant (FR) finishing is crucial for developing protective textiles, traditionally relying on halogen, phosphorus, and phosphorus-nitrogen chemistries, which have limitations like toxicity and fabric stiffening. Innovative approaches such as nanotechnology, plasma treatments, and natural resource-based finishes are being explored to achieve sustainable FR textiles. This study presents the development and comprehensive characterization of hydrogel composites made from nonwoven fabrics composed of various hemp/wool blends (70/30, 80/20, and 90/10). The nonwoven fabrics were treated with a chitosan hydrogel incorporating banana sap to enhance their properties. Scanning electron microscope (SEM) examined the surface morphology and structural integrity of the composites, while Fourier transform infrared spectroscopy (FTIR) identified chemical interactions and functional groups. Differential scanning calorimeter (DSC) revealed thermal properties, water absorbency tests demonstrated hydrophilicity, mechanical testing assessed tensile strength, and vertical flammability tests evaluated fire resistance. SEM and FTIR revealed a successful coating of chitosan hydrogel with banana sap inclusions onto the hemp/wool nonwoven fabric, forming a composite structure. DSC analysis suggests higher chitosan content and hemp fiber ratio (like 70/30) lead to increased thermal stability of hydrogel composites. Higher chitosan concentrations in the hydrogel significantly improve the flame-retardant properties of hemp/wool nonwoven fabrics by reducing char length and enhancing protective char layer formation, with banana sap further promoting charring. These results indicate that the developed composite can be effectively used in flame-retardant textiles.

Biomass aerogel with humidity sensitive for thermal runaway suppression of battery modules and flame-retardant application

The propagation of thermal runaway (TR) is a critical safety issue in lithium-ion battery modules, which can be mitigated by using aerogels, a new nano porous material with exceptional thermal insulating capabilities and flame resistance. In this study, we developed an environmentally friendly aerogel by combining chitosan (CS) and phytic acid (PA) through ambient pressure drying. The optimal PA composition was 5 wt%, and the corresponding aerogel achieved a limit oxygen index (LOI) value of 45.6 % and V-0 rate in UL-94 tests, demonstrating excellent flame retardancy. With a low density of 0.163 g/cm³, the aerogel exhibited a thermal conductivity of 0.0309 W/(m·K), making it an effective thermal insulator. The rigid porous structure of the composite aerogel provided a maximum compressive strength of 25.8 MPa and a compressive modulus of 5.58 MPa. To study the effect of the aerogel in mitigating TR, we simulated TR conditions by heating blocks to 300 °C. The aerogel significantly reduced the temperature rise in adjacent blocks, effectively inhibiting TR propagation. These findings indicate that the CS/PA aerogel offers superior thermal insulation, flame-retardant properties, and robust mechanical strength, making it a promising material for enhancing the safety of lithium-ion battery modules.

Study on preparation and performance of bagasse/sodium carboxymethyl cellulose gel for inhibiting coal spontaneous combustion

In order to effectively prevent and control coal spontaneous combustion and improve the safety of coal mining, bagasse carboxymethy cellulose (BCC) prepared from bagasse (BS) and sodium carboxymethyl cellulose (CMC) were used as the substrates. A gel (BCC-CMC) for inhibiting coal spontaneous combustion was prepared using a chemical crosslinking method involving zirconium citrate crosslinking and glucono-delta-lactone (GDL) modification. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy were utilized to characterize both the crystal and molecular structure of bagasse and its derived bagasse carboxymethyl cellulose. The results indicated that new carboxymethyl groups were introduced into bagasse during the treatment, facilitating the successful extraction and preparation of sodium carboxymethyl cellulose. The results of viscosity and bonding tests demonstrated that the concentration and dosage of CMC had the most significant influence on the gel viscosity, which remained higher and more stable at room temperature. The coal bonded by the gel coal mixture can effectively seal surface cracks, with a bonding degree of up to 70.72 %. TG-DTG, temperature-programmed oxidation experiment and FTIR analyses revealed that, compared to raw coal, coal samples treated with gel exhibited improved stability, fewer active groups, and fewer oxygen-containing functional groups, effectively inhibiting coal’s low temperature oxidation and reducing the risk of spontaneous combustion. The gel is environmentally friendly, cost-effective, and exhibits good flame retardant properties. This study is of great significance for preventing and controlling coal spontaneous combustion, effectively ensuring the safe production of coal resources and the safety of mine workers, achieving the green sustainable development of the mine.

Urchin-like NiCo-based bimetallic hydroxide decorated with DOPO as highly hydrophobic flame retardant for remarkably reducing fire hazard of poly (L-lactic acid)

Designing high-performance flame retardants for poly (L-lactic acid) (PLA) materials and exploring a simple and scalable strategy have been hot topics in research. In this work, a novel and highly efficient flame retardant, that is, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) decorated urchin-like NiCo-based bimetallic hydroxide (NiCo-BH@DOPO), was synthesized and incorporated into PLA to prepare PLA and NiCo-BH@DOPO (PLA/NiCo-BH@DOPO) composite. Benefiting from the DOPO organic modification, NiCo-BH@DOPO had superb hydrophobicity and presented excellent dispersion in the PLA matrix. When 20 wt% NiCo-BH@DOPO was added, the LOI value of PLA/NiCo-BH@DOPO composites reached 33.2 %, passed the V-0 level of UL-94 grade, and its maximum peak heat release rate (PHRR) and total heat release (THR) were reduced by 13.2 % and 17.3 %, respectively, compared with PLA/NiCo-BH composites. Furthermore, the residue of PLA/NiCo-BH@DOPO at 800 °C reached 19.8 wt% and the T10% (temperature at 10 % weight loss) increased by 33 °C. More importantly, the residual PLA/NiCo-BH@DOPO char exhibits a significantly reduced presence of large cracks compared to PLA/NiCo-BH, indicating a more compact formation of residual char. NiCo-BH@DOPO endowed PLA with outstanding flame retardancy, thermal stability and carbonization properties, which were owing to the multi-coordinating effect transition metal (NiCo-BH) catalyzed the char formation to form a char layer barrier and DOPO free radicals captured to inhibit the combustion reaction chain. This investigation provided a facile strategy for the novel multi-function NiCo-based bimetallic hydroxide flame retardant, expanding NiCo-BH potential applications in PLA.

Sustainable lignosulfonate-modified PA6.6 fabrics to improve durable flame retardancy, hydrophilicity and mechanical performance

Creating durable flame retardancy, enhanced mechanical performance, and hydrophilic polyamide 6.6 (PA6.6) textiles via cost-effectiveness from sustainable renewable sources is a considerable challenge. This study introduces a pretreatment process involving the application of sodium lignosulfonate (LS) to the surface of PA6.6 fabrics, thereby enhancing their hydrophilic and flame-retardant properties. Subsequently, a layer-by-layer (LbL) nanocoating treatment is employed, utilizing renewable polyelectrolytes—chitosan (CS), LS, and poly (sodium phosphate) (PSP)—to create 8-bilayer (BL) and 4-quarda layer (QL) structures that further improve the hydrophilicity and durable flame resistance of PA6.6 fabrics. The combined LS-modified and LbL coatings notably increased the limiting oxygen index (LOI) values from 19.5 % to 22.5 %, eliminated melt dripping, and secured a V-1 rating in the vertical burning (UL-94) tests. Moreover, the treated fabrics exhibited a 43 % reduction in the peak heat release rate (PHRR) and a lower fire growth rate (FGR) of 0.84 W/g·s, with a significant increase in char yield% in both air and nitrogen (N2) atmospheres. A cross-linked network structure is responsible for the superior hydrophilicity, enhanced tensile strength, and fabric softening properties. The self-crosslinking of sulfur-containing radicals with amide units ensures an anti-dripping performance that can withstand up to 30 home laundering cycles, demonstrating remarkable washing durability. However, a convincing approach has been developed for sustainable and high-performance materials for the textile industry, and a simple LbL technique using renewable polyelectrolytes that have traditionally been utilized in water treatment and food processing has been developed.

High-temperature resistant SnSe/MSN film for thermal runaway prevention in lithium-ion batteries

Recent years have witnessed an accelerated development of electric vehicles (EVs) driven by the pressing need to curb carbon emissions. Lithium-ion batteries (LIBs) stand out as preferred energy storage solutions owing to their high energy density and extended cycle life. Nonetheless, the persistent threat of thermal runaway (TR) remains a critical safety concern. This study endeavors to tackle this issue by introducing a novel composite insulating film tailored to function as a thermal barrier within LIBs. Comprising exfoliated SnSe (tin selenide) and mesoporous silica bonded via Zn ion gelation, the composite showcases a low thermal conductivity of 0.131 W/mK alongside a robust tensile strength of 52.7 MPa. These attributes stem from the distinctive amalgamation of materials and the robust interfacial interactions facilitated by Zn ion gelation, thus enhancing thermal stability and mechanical resilience. The devised DGEBA/SnSe-MSN composite exhibits notable flame retardant properties and superior thermal management capabilities, positioning it as a promising candidate to bolster the safety and dependability of LIBs. This research introduces a promising approach for crafting high-performance insulating films applicable across diverse industries, particularly in the realm of lithium-ion battery technology, leveraging SnSe as an insulating material—a departure from its prior application as a thermoelectric material.

Flame Retardancy and Thermal Stability of Rigid Polyurethane Foams Filled with Walnut Shells and Mineral Fillers.

Recently, the influence of the concept of environmental sustainability has increased, which includes environmentally friendly measures related to reducing the consumption of petrochemical fuels and converting post-production feedstocks into raw materials for the synthesis of polymeric materials, the addition of which would improve the performance of the final product. In this regard, the development of bio-based polyurethane foams can be carried out by, among other things, modifying polyurethane foams with vegetable or waste fillers. This paper investigates the possibility of using walnut shells (WS) and the mineral fillers vermiculite (V) and perlite (P) as a flame retardant to increase fire safety and thermal stability at higher temperatures. The effects of the fillers in amounts of 10 wt.% on selected properties of the polyurethane composites, such as rheological properties (dynamic viscosity and processing times), mechanical properties (compressive strength, flexural strength, and hardness), insulating properties (thermal conductivity), and flame retardant properties (e.g., ignition time, limiting oxygen index, and peak heat release) were investigated. It has been shown that polyurethane foams containing fillers have better performance properties compared to unmodified polyurethane foams.

Pyrolysis kinetics and flame retardant enhancement of bio-based polyamide 56/6

The development of polyamide materials with fire safety is of great importance at this stage. A novel nitrogen-phosphorus bisystem flame retardant (MC) with a multi-branched structure was synthesized and applied to a new bio-based polyamide 56/6 (PA56/6). Notably, at 8 wt% MC content, flame-retardant PA56/6@MC8% (FRPA56/6@MC8%) achieved an Limiting Oxygen Index (LOI) of 26.6% and a V-0 rating in UL-94 tests. Cone calorimetry results indicated that FRPA56/6@MC8% exhibited a 22.9% reduction in total heat release (THR) and a 41.0% decrease in peak heat release rate (PHRR), underscoring the flame retardancy promotion by MC in PA56/6. The study further explored the pyrolysis kinetics and mechanisms of polyamide materials, offering insights crucial for flame-retardant modifications. Overall, the findings present an innovative strategy for enhancing the flame retardant properties of PA56/6, potentially applicable in automotive components and other pertinent fields.

Comparison of the Characteristics of Baekak(chalk) and Hobun(shell) Pigment for Dancheong based on Natural Raw Materials

Calcium carbonate white pigments were manufactured by classifying them into Baekak(chalk) and Hobun(Shell) according to the type of natural raw material, and their material characteristics were analyzed. Their performances were compared by evaluating their weather resistance, antifungal activity, and flame retardancy. The main components of Baekak pigments are calcite and dolomite, and those of Hobun pigments a re calcite and a ragonite. Depending on the raw material, the specific factors identified are Mg from the mineral composition of Baekak pigments, and P and S from the protein composition of Hobun pigments. The particle shape of the pigment shows a crystal structure unique to minerals in the case of Baekak pigments, but the Hobun pigments are classified into plate-shaped or columnar structures depending on the raw material and are in an aggregated state with a large specific surface area. While the absorption amount of Baekak pigments made from limestone and dolomite is similar, that of Hobun pigments shows differences depending on the raw material, with the absorption amount being high in the order of oyster > cockle > clam. As a result of the color analysis, both the Baekak and the Hobun pigments had L* values of over 90 and opacity of over 90, indicating good whiteness and painting workability. As a result of the accelerated weathering test, the final color difference value(ΔE) was less than 2.02, which was difficult to recognize with the naked eye, and the Hobun pigment showed superior color and film stability compared to the Baekak pigment. As a result of the antifungal test, all calcium carbonate-based white pigments showed high preventive effects against decay fungi, and among them, the pigment made from clams and cockles showed excellent antiseptic properties. In addition, the pigment made from clams and cockles has been shown to have flame retardant properties, and it is expected that it will contribute to enhancing the preservation of organic cultural heritage when applied to it.

Innovative silica aerogel fiberglass walls and roofs: A path to lower carbon emissions and higher energy savings

ABSTRACT Buildings account for a significant portion of global energy use and consumption. Buildings have substantial energy consumption due to the use of heating, ventilation, and cooling systems. It is evident that the insulation materials used in the design of building envelopes can efficiently reduce the cost of air conditioning by reducing external heat gains and losses. Additionally, the use of environmentally friendly and cost-effective can be beneficial from an environmental standpoint. This paper aims to evaluate the potential for cost savings in the air conditioning of buildings incorporated with silica aerogel fiberglass insulation in hollow concrete bricks (wall) and hollow roof tile (roof). Silica aerogel fiberglass insulation is extensively used for heat insulation purposes, including building insulations, due to its superior thermal insulation and flame retardant properties. The thermo-physical properties of silica fiberglass insulation and building materials were determined experimentally as per ASTM D 5334 standards. Twenty distinct building design concepts are investigated in this study, each featuring insulation-integrated concrete blocks composed of silica aerogel fiberglass: (WEM1) insulation layer in the outer side, (WEM2) insulation layer in the center, (WEM3) insulation layer in the inner side, (WEM4) insulation layers in the outer-middle, (WEM5) insulation layers in the middle-inner, and (WEM6) insulation layers in the outer-inner sides. Additionally, two arrangements of insulation-stuffed roof tiles, REM1 above the RCC and REM2 below the RCC. In addition, novel building designs integrated with insulation were analyzed numerically, related to environmental conditions that refer to two different scenarios in India (hot dry and composite climates). Thermo-economic analysis of novel wall and roof designs with silica fiberglass insulation materials on air-conditioning costs, carbon dioxide emissions, and payback time are compared with conventional roof and wall patterns. The thermo-economic analysis was carried out based on the number of degree-hours of heating and cooling to determine the building’s annual energy usage. The building model arrangement (WEM6-REM1), which consists of an insulation composite wall (WEM6) and insulation roof tile (REM1), demonstrated the greatest annual air conditioning cost savings of 3.4 $/m2/year and 1.74 $/m2/year when compared to conventional building design for climatic conditions of Kurnool and Gauhati. The building model arrangement (WEM6-REM1) composed of silica fiberglass aerogel insulation exhibits the highest reduction in carbon emissions of 65 kg/kWh and 33 kg/kWh, when compared to conventional building design analyzed in both hot-arid; (Kurnool) and composite (Gauhati) climatic conditions. The placement of insulation in the roof alone (REM1) has the shortest payback duration of 2.15 years. The results of this study point to a viable approach to enhancing building design decision-making and narrowing the performance gap in sustainable and energy-efficient strategies.

Enhanced flame retardancy and thermal insulation of epoxy resins composites incorporated with ammonium polyphosphate and ionic liquids loaded CuO-ZnO hollow spheres

Epoxy resin, as a thermosetting polymer material with good performance, has been limited in application due to its high flammability. In this investigation, porous CuO-ZnO hollow spheres (CZHS) were prepared by a hydrothermal method. By incorporation with ionic liquids loaded CuO-ZnO hollow spheres (CZHS@Ils) and ammonium polyphosphate (APP) into epoxy resin (EP) matrix, a new composite flame retardant material, named as EP/7.5APP/1.5CZHS@ILs, was developed for improvement of their thermal insulation and flame retardancy. The thermal conductivity of EP/7.5APP/1.5CZHS@ILs was measured to be 0.0197 W m −1 K −1, which is lesser than that of APP incorporated epoxy resin (EP/APP), demonstrating good thermal insulation capability. The flame retardancy were assessed using the limiting oxygen index (LOI) test, the Vertical flame testing (UL-94) test, and the cone calorimeter (CC) test. The results obtained from LOI test show that the EP/7.5APP/1.5CZHS@ILs has good flame retardancy with a LOI value of up to 28, better than that of pure EP which has a LOI value of 19.2. Moreover, a V-0 level of the EP/7.5APP/1.5CZHS@ILs was observed from the UL-94 test. The peak heat release rate (PHRR) was reduced to 257.9 kW m−2, which is 74.8 % lower than that of the pure EP. Such results are attributed to the synergy effect of CZHS@ILs and APP which offers the epoxy resin excellent flame retardancy. Taking advantages of the excellent thermal insulation, flame retardancy and better mechanical properties, the as-resulted EP/7.5APP/1.5CZHS@ILs may hold great potential for future thermal insulation and flame-retardant applications of energy saving building.

Advanced flame-retardant melamine foam with ultra-sensitivity and prolonged fire warning, featuring smart device-integrated graphene oxide/attapulgite nano-coating

Enhancing flame retardancy and fire-warning capabilities of thermal insulation materials used in building external walls is crucial for ensuring fire safety as well as guarding people's lives and assets. Herein, we have developed an environmentally friendly nano-coating that possesses flame-retardant and early-warning properties by integrating graphene oxide (GO) and attapulgite (ATP) onto melamine foam (MF) through a layer-by-layer self-assembly method (LBL). The GO-ATP-MF composite demonstrates a rapid response to flame (<1 s) due to GO's thermally induced reduction. Additionally, ATP's synergistic flame-retardant effects on both gas and condensed phases contribute to outstanding flame retardancy, enabling an enduring fire alarm duration (>1330 s). The warning duration time of this composite surpasses the majority of GO-based fire-warning nano-coatings reported to date. Moreover, incorporating a Bluetooth wireless transmission system facilitates real-time fire information sharing among smart devices, thereby optimizing fire signal transmission efficiency. Thus, this study advances GO-based flame-retardant nano-coatings and devices with high sensitivity and prolonged fire-warning capabilities, providing an innovative idea to enhance the fire safety of MF as a thermal insulation material.

Safety research of textile materials with flame retardant properties

This article discusses the findings of a study that explored the use of new compositions containing tetraethoxysilane, sodium dihydrogen phosphate, and hexamethylenediamine to improve the flame retardancy of cellulose fiber materials. The impact of different components and temperatures on the fire-resistant properties of the fabric was examined. In an untreated sample measuring 17*22 cm, ignition occurred in 15 seconds and the fabric burned completely within 60 seconds, whereas a treated sample showed signs of retardation. Increasing the concentration of flame retardant impregnation at a temperature of 150 degrees had minimal effects on the material's strength, air permeability, and appearance. With the help of electron scanning device it was found that on the surface of the fibers of the treated sample morphological changes were observed in the form of film, which in turn contain particles of Si (25.48%), P (17.61%), Na (1.70%). The optimum conditions of fabric processing are determined, the influence of concentration of working solution, impregnation and thermofixation temperature on flame retardant properties of fabrics investigated, also processing can be carried out on standard equipment of finishing enterprises and laboratories. Cotton materials treated with a compound based on tetraethoxysilane, sodium dihydrophosphate and hexamethylenediamine provides adequate fire resistance.

Flame retardant polyurethane foam prepared from compatible blends of ammonium ligninsulfonate-based and zinc alginate

Abstract Zinc alginate (ZnAlg) was prepared and subsequently employed to modify ammonium ligninsulfonate-based polyurethane foams (PUFs). A range of analytical techniques, including thermogravimetry, integral programmed decomposition temperature, activation energy, smoke density, cone calorimetry and scanning electron microscopy, were employed to characterise the modified PUFs. The results demonstrated that the PUFA15Z5 (15 % ammonium lignin sulfonate and 5 g ZnAlg) with the lowest mass loss exhibited the second-highest sample decomposition temperature (T50 %), second-highest peak temperature (TMAX2), IPDT and activation energy. Furthermore, the PUFA15Z5 sample exhibited the smallest smoke density (23.11) and the highest light transmittance (67.11 %). The peak heat release rate, total heat release, smoke production rate, total smoke release and four fire risk assessment indicators of the PUFA15Z5 were the lowest, while its carbon residue was the densest. The results demonstrated that the PUFA15Z5 exhibited the most favourable thermal stability, flame retardant properties and the lowest smoke toxicity. These findings provided a valuable reference for subsequent biomass-based flame retardant modified polyurethane foams (PUFs).

Boosting Flame Retardancy of Polypropylene/Calcium Carbonate Composites with Inorganic Flame Retardants.

This study investigates the effects of inorganic flame retardants, zinc borate, and magnesium hydroxide, on the thermal, morphological, flame retardancy, and mechanical properties of polypropylene (PP)/calcium carbonate composites for potential construction industry applications. Polypropylene/calcium carbonate (50 wt.%) composites containing 5 and 10 wt.% flame retardants were prepared using a batch mixer, followed by compression moulding. The results demonstrated enhanced thermal stability, with the highest char residue reaching 47.2% for polypropylene/calcium carbonate/zinc borate (10 wt.%)/magnesium hydroxide (10 wt.%) composite, a notably strong outcome. Additionally, the composite exhibited an elevated limited oxygen index (LOI) of 29.4%, indicating a synergistic effect between zinc borate and magnesium hydroxide. The proposed flame retardancy mechanism suggests that the flammability performance is driven by the interaction between the flame retardants within the polypropylene/calcium carbonate matrix. Magnesium hydroxide contributes to smoke suppression by releasing water, while zinc borate forms a protective glassy foam that covers the burning surface, promoting char formation and acting as a physical barrier to heat transmission and fire spread. Scanning electron microscopy confirmed good dispersion of the additives alongside calcium carbonate within the polymer matrix. Despite the addition of up to 10 wt.% flame retardants, the composites maintained high-notched impact strength.

Thermally-stable and flame-retardant metal-organic framework-based separator for high-performance lithium-ion batteries

Safety hazards hinder the development of lithium-ion batteries (LIBs), in which the failure of separator is a key point. However, commercial polyolefin separators display poor thermal stability and flame-retardant property. Aramid nanofiber (ANF) is a promising material for safer separators in batteries due to its excellent thermal stability and remarkable flame retardancy, but the pure ANF separator often shows low ionic conductivity because of the tightly packed fibers. Metal-organic framework (MOF) is a promising candidate for increasing the porosity and ionic conductivity of ANF separator due to its ultrahigh porosity and ultrahigh specific area. Herein, a thermally-stable and high-performance composite separator is fabricated by combining MOF pore-forming agent and ANF network skeleton. The MOF/ANF1composite separator with 10 wt% ANF shows excellent thermal-stability (melting-point above 300 °C and decomposition temperature above 500 °C) and remarkable flame-retardant property. And it exhibits high ionic-conductivity of 1.01 mS·cm−1, contributed to the superior long-term cycling performance of the coin cell with the capacity of 147.3 mAh·g−1 after 200 cycles at 1 C, almost 25.4 % higher than that of the coin cell with PP separator for LIBs. The strategy of this research provides new ideas for the design of high-safety LIBs.

Preparation of a bifunctional precursor with antibacterial and flame retardant properties and its application to cotton fabrics

Cotton fabric is a cellulose-based material with complex capillary spaces, which enhance breathability and softness. However, these capillary spaces can promote bacterial growth with moisture during storage and daily use. Additionally, cotton fibers are highly flammable, posing a fire hazard to wearer. The lack of inherent antibacterial and flame retardant properties in cotton fabric limits its applications. In this paper, the triazole compound containing Schiff base (NABTA) was synthesized from 3-bromopropene, p-hydroxybenzaldehyde and 3-amino-1,2,4-triazole, followed by an addition reaction between Schiff base activity and 9,10-dihydro-9-oxa-10-phospha-phenanthrene-10-oxide (DOPO) to synthesize an antibacterial and flame retardant precursor (NABTA-DOPO). The structure of NABTA and NABTA-DOPO was characterized by FTIR and NMR. NABTA and NABTA-DOPO were applied to cotton fabrics to investigate and compare their antibacterial properties and thermal stability. The results showed that all the cotton fabrics treated with NABTA and NABTA-DOPO had favorable antibacterial effects. The introduction of DOPO had no significant effect on the antibacterial effect and mechanism of the fabrics. However, it otherwise improved the burning stability of treated cotton fabrics. The antibacterial activity of 10 g/L NABTA-DOPO treated cotton fabrics after chlorination against E. coli and S. aureus was over 99.99 %. The vertical burning test results showed that cotton fabrics treated with a concentration of 50 g/L NABTA-DOPO had improved flame retardant properties with a damaged length of 5.9 cm. In addition, the storage, washability, UV stability and antibacterial reproducibility experiments demonstrated the excellent durability and reproducibility of the N-halamine structure of chlorinated cotton fabrics. This study enhances cotton fabric by synthesizing and applying NABTA and NABTA-DOPO, resulting in improved multifunctionalities, including antibacterial properties, flame retardancy, UV resistance, and wettability.

Investigation of the Effects of Phosphate-Containing Flame-Retardant Chemicals on Particleboards Produced Using Urea-Formaldehyde Resin.

In this study, urea-formaldehyde resins containing different phosphate-based flame retardants (FRs) were prepared to produce wood-based panels (medium-density fiberboard, particleboard, and veneer board), and their flammability properties were investigated. The changes in the gelation times were investigated when the phosphate-containing FRs used in different amounts were mixed with the resin. Chemicals that have both hardener and flame-retardant properties at the same time have been studied. In addition, the pH and thermal analyses of the resin and flame-retardant mixtures prepared in this study were performed by a pH meter and thermogravimetric analysis, respectively. The limiting oxygen index, UL-94 vertical burning, and cone calorimetry tests on the samples with the best combustion characteristics were carried out by sizing the particleboards in accordance with the standards and applying the prepared flame-retardant resins on them. The distribution of flame-retardant resin on the particleboard surface was investigated for the samples prepared by scanning electron microscopy. As a result of the analyses, it was determined that the samples containing 20% ammonium polyphosphate had good nonflammability properties.

Multifunctional fluorinated phosphonate-based localized high concentration electrolytes for safer and high-performance lithium-based batteries

This study introduces a novel fluorinated phosphonate-based additive, Bis(2,2,2-trifluoroethyl)(methoxycarbonylmethyl)phosphonate (BTCMP), in a localized high-concentration electrolyte (LHCE) to address key challenges in lithium metal batteries (LMBs), such as dendritic lithium growth and porous electrode morphology. The pristine LHCE forms a fluorine-rich solid electrolyte interphase (SEI) layer, primarily composed of lithium fluoride (LiF). However, the pristine LHCE suffers from severe electrolyte decomposition, forming a thicker and more resistive cathode electrolyte interphase (CEI), leading to increased impedance and reduced cyclability. Interestingly, Density Functional Theory (DFT) investigations revealed that the BTCMP inclusion modifies the solvation structure by dispersing the aggregates into smaller fragments, facilitating easier Li+ migration than the pristine LHCE. The addition of BTCMP suppresses solvent decomposition as confirmed by an increasing trend in the lowest unoccupied molecular orbital (LUMO) of corresponding LHCE molecules. Further, the presence of BTCMP results in a thinner and more stable CEI, reducing electrolyte decomposition, maintaining better ion transport, and preserving the cathode's structural integrity, as supported by TEM and XPS analysis. The BTCMP-based F-rich LHCE retained 82 % of its initial capacity while maintaining a coulombic efficiency of 99.5 % after 200 cycles in a Li||LNMO cell while the pristine LHCE only retained 47.2 % of initial capacity post-150 cycles. Additionally, the flame-retardant properties of BTCMP-based LHCE highlight its safety compared to commercial electrolytes.

Freeze-Cast MIL-53(Al) Porous Materials with High Thermal Insulation and Flame Retardant Properties.

The development of materials with superior thermal insulation and flame retardancy is critical for industrial applications and daily life. Metal-organic framework (MOF)@poly(vinyl alcohol) (PVA) (MOF@PVA) aerogel composites have demonstrated remarkable thermal insulation and flame retardancy properties. In this work, MIL-53(Al) was directly mixed with PVA and formed by freeze-drying, and the influence of the pore structure on the thermal insulation and flame retardancy properties of the materials was investigated. The incorporated MIL-53(Al) nanoparticles introduced abundant micro- and mesopores, enhancing the complexity of the pore structure and improving the thermal insulation and flame retardancy properties of the aerogels. The directionally freeze-cast aerogel achieved a thermal conductivity of 0.040 W·mK-1, and maintained excellent thermal insulation ability even at 220 °C. Furthermore, the aerogel exhibited nonflammable and self-extinguishing characteristics. This environmentally friendly manufacturing method provides new ideas for the design of MOF-based composites, thereby expanding their application areas.