Contemporary industrial sectors are experiencing a growing imperative for coatings that exhibit a multi-tude of functions.In this study,PBP-Ce(Ш)nanosheets,characterized by robust structural stability,were synthesize...Contemporary industrial sectors are experiencing a growing imperative for coatings that exhibit a multi-tude of functions.In this study,PBP-Ce(Ш)nanosheets,characterized by robust structural stability,were synthesized using a one-pot method and incorporated into waterborne epoxy resin(WEP)to formu-late nanocomposite coatings.The findings demonstrate that the coating,containing 0.6 wt.%PBP-Ce(Ш)nanosheets,exhibits superb anti-corrosion,flame-retardant,and wear-resistant properties.Upon 42 days of 3.5%NaCl solution immersion,the fb of the 6-PBTC coating was a mere 3.55 Hz,significantly lower than the 309.51 Hz measured for the pure WEP coating.Furthermore,the Peak heat release rate(PHRR)of the microscale combustion calorimeter(MCC)and the wear rate of the 6-PBTC coating were reduced by 41.63%and 84.65%,respectively,in comparison to the pure WEP coating.This work not only delves into the utilization of BP nanosheets but also presents a viable solution for advancing the development of multifunctional coatings.展开更多
A halogen-free flame-retardant (hydroquinone bis (N,N’-diarylphosphoramidate),4N-HDP) containing phosphorus-nitrogen was synthesized.Its structure was characterized by infrared spectroscopy (IR),nuclear magnetic reso...A halogen-free flame-retardant (hydroquinone bis (N,N’-diarylphosphoramidate),4N-HDP) containing phosphorus-nitrogen was synthesized.Its structure was characterized by infrared spectroscopy (IR),nuclear magnetic resonance (^(1)H-NMR and^(31)P-NMR).Thermogravimetric analysis (TG),limiting oxygen index (LOI),UL-94 vertical burning test (UL-94),thermogravimetric-infrared instrument (TG-IR) and scanning electron microscopy (SEM) were used to compare the flame-retarding performance and mechanism of hydroquinone bis (diphenyl phosphate) (HDP) and 4N-HDP.TG,IR and TG-IR were used for comparative analysis,indicating that both HDP and 4N-HDP are flame-retardants,and the gas phase and condensed phase act synergistically.In the pyrolysis process,it is divided into two steps:the first step is the breakage of large molecules to small molecules;the second step is the gasification and carbonization of small molecules,and eventually produces phosphate ester and non-flammable gases.Through the comparison of various results,it could be found that 4N-HDP has better flame-retarding performance compared to HDP in the composite with polycarbonate (PC).展开更多
The effect of potash as a nondurable finish on the flammability of 100% cotton fabric （plain 180 g/m^2） was investigated. The bone-drled weighed fabrics were dipped into suitable concentrations of potash, with a vol...The effect of potash as a nondurable finish on the flammability of 100% cotton fabric （plain 180 g/m^2） was investigated. The bone-drled weighed fabrics were dipped into suitable concentrations of potash, with a volume of 100 mL at 20-2℃. The impregnation was followed by means of squeeze rolls and drying at 110 ℃. The samples were then reweighed with analytical precision. After conditioning overnight by using our ＂vertical flame tester＂ the optimum add-on values to impart flame-retardancy to cotton fabric was determined and expressed by 0.80 g of potash per 100 g fabric to be an efficient addition. Thermogravimetric analysis of pure cotton, treated cotton with potash at its optimum efficiency for donation of flame-retardancy into cotton fabric was fulfilled and the thermograms were compared and commented. The effectiveness of this hydroxide was attributed to the heat dissipation by the remaining consumed material during the combustion. The results obtained are in favor of ＂Dust or Wall Effect Theory＂.展开更多
We have investigated the effect of zinc oxide as a photocatalyst and durable flame-retardant on cellulosic fibers. Zinc oxide nanocrystals were successfully synthesized and deposited onto cellulosic fibers using sol-g...We have investigated the effect of zinc oxide as a photocatalyst and durable flame-retardant on cellulosic fibers. Zinc oxide nanocrystals were successfully synthesized and deposited onto cellulosic fibers using sol-gel process at low temperature. The samples were characterized by means of several techniques such as scanning electron microscopy, transmission electron microscopy, diffuse reflectance spectroscopy, X-ray diffraction and thermogra- vimetric analysis. The photocatalytic activity was tested by measuring the photodegradation of methylene blue under UV-Vis illumination. Moreover, flame-retardancy was tested by vertical flame spread test. The optimum add-on value for donating flame-retardancy onto cellulosic fabric was obtained to be in the range of 15.24 to 23.20 g of the ZnO per 100 g of fabric. Thermogravimetric analysis of pure and flame-retarded samples were accomplished and discussed. The results obtained are in agreement with Wall effect theory and Coating theory. The originality of this work on introducing photoactive flame-retarded fibers is highly valuable for industrial implementation.展开更多
Compared to natural woods,synthetic woods have superior mechanical stability,thermal insulation,and flame retardancy owing to their hierarchically cellular microstructures and intrinsic advantages of the thermosetting...Compared to natural woods,synthetic woods have superior mechanical stability,thermal insulation,and flame retardancy owing to their hierarchically cellular microstructures and intrinsic advantages of the thermosetting matrix.Increasing the long-time fire resistance is very important to the practical application.In this study,we present a novel coating strategy by a vacuum-assisted sonication technique(sonocoating)with a rectorite nanosheet dispersion to create a uniform nanocoating on the channel walls of synthetic wood.Owing to ultrasonic energy and vacuum pressure,the nanosheet dispersion can penetrate deep down to form a layered nanocoating on the channel surface.The coated synthetic woods can withstand fire(400-600℃)for more than 10 min with 62%mass retainment,surpassing uncoated synthetic woods and natural woods.Therefore,as a lightweight and strong composite with enhanced flame-retardant performance,the coated synthetic woods have huge potential applications in safe and energy-efficient buildings.展开更多
The alternating copolymer of CO_(2) with epoxide is a green plastic that can efficiently transform CO_(2) into valuable chemicals. Despite the significant advances made, the restricted practical application of CO_(2)-...The alternating copolymer of CO_(2) with epoxide is a green plastic that can efficiently transform CO_(2) into valuable chemicals. Despite the significant advances made, the restricted practical application of CO_(2)-sourced polycarbonates due to their lack of functionality has hindered field development. We successfully demonstrated the flame retardancy of poly(chloropropylene carbonate) (PCPC), a perfectly alternating copolymer of epichlorohydrin (ECH) and CO_(2). This was prepared at a 200-gram scale using a high-efficacy tetranuclear organoborane catalyst. PCPC’s excellent flame-retardant performance has been proven by both the vertical combustion test (UL94 V-0) and the limiting oxygen index (LOI) value (29.1%). The underlaid flame-retardant mechanism of PCPC was clearly elucidated. As a result, we confirmed that the generated cyclic carbonates and concurrently released flame-retardant chlorine radicals, hydrogen chloride, and CO_(2) during combustion render PCPC an excellent flame retardant. Furthermore, we investigated the practicability of PCPC as a halogen-rich polymeric flame retardant by blending it with commercial bisphenol A polycarbonate (BPA-PC). PCPC upgraded the flame retardancy rating of BPA polycarbonate from V-2 to V-0 even with a mere 1 wt% addition. It is our hope that this result will prove useful in future developments of advanced CO_(2)-sourced polymeric materials.展开更多
Poor formability is a key problem that limits the application of flame-retardant Mg-Al-Ca based alloys at room temperature.In this study,we present a new Mg-6Al-3Ca-0.4Mn-2Zn(wt%)alloy which exhibits excellent flame-r...Poor formability is a key problem that limits the application of flame-retardant Mg-Al-Ca based alloys at room temperature.In this study,we present a new Mg-6Al-3Ca-0.4Mn-2Zn(wt%)alloy which exhibits excellent flame-retardant performance and excellent formability.Due to the high Ca content,the Mg-6Al-3Ca-0.4Mn-2Zn(wt%)alloy does not burn at 1065℃.The formability of the alloys is measured using a three-point bending test,and the Mg-6Al-3Ca-0.4Mn-2Zn(wt%)alloy shows excellent formability,with a significant increase in bending displacement from 7.1 mm to 23.8 mm compared to the Mg-6Al-3Ca-0.4Mn(wt%)alloy.The combined effect of the weakened basal texture,the reduction of twins and the plastically deformable Al2Ca phase particles ensures good formability of the Mg-6Al-3Ca-0.4Mn-2Zn(wt%)alloy.The dynamic recrystallization mechanisms of the alloys have been analyzed,and the promotion of dynamic recrystallization by the PSN mechanism is responsible for the weakened basal texture and the reduction of twins in the Mg-6Al-3Ca-0.4Mn-2Zn(wt%)alloy.The new Mg alloy is attractive for industrial applications due to its excellent flame-retardant performance and formability.展开更多
The effect of extrusion temperature on the dynamic recrystallization behavior and mechanical properties of the flame-retardant Mg−6Al−3Ca−1Zn−1Sn−Mn(wt.%)alloy was investigated.The observed dynamic recrystallization m...The effect of extrusion temperature on the dynamic recrystallization behavior and mechanical properties of the flame-retardant Mg−6Al−3Ca−1Zn−1Sn−Mn(wt.%)alloy was investigated.The observed dynamic recrystallization mechanisms in the alloy include continuous dynamic recrystallization(CDRX)and particle simulated nucleation(PSN)during hot extrusion.A significant increase in yield strength,from 218 to 358 MPa,representing a 140 MPa increase,is achieved by decreasing the extrusion temperature.The strengthening mechanisms were analyzed quantitatively,with the enhanced strength primarily attributed to grain boundary and dislocation strengthening.The plasticity mechanism was analyzed qualitatively,and the increase in the volume fraction of unDRXed grains caused by the decrease in extrusion temperature leads to an increase in the number of{1012}tensile twins during the tensile deformation,resulting in a reduction in plasticity.展开更多
Single ion gel polymer electrolyte has the advantages of high Li^(+)conductivity and dendrite mitigation.However,the addition of organic solvent makes the electrolyte flammable,posing serious safety hazards.Herein,we ...Single ion gel polymer electrolyte has the advantages of high Li^(+)conductivity and dendrite mitigation.However,the addition of organic solvent makes the electrolyte flammable,posing serious safety hazards.Herein,we report a flame-retard ant cross-linked sp^(3)boron-based single-ion gel polymer electrolyte(BSIPE).BSIPE was prepared by a simple one-step photoinitiated in situ thiol-ene click reaction.Due to the boron-based anions being immobilized in the cross-linking network,the developed BSIPE/PFN exhibits a high t_(Li^(+))(0.87),which can mitigate concentration polarization phenomenon and suppress the growth of lithium dendrites.BSIPE/PFN plasticized with triethyl phosphate(TEP),fluoroethylene carbonate(FEC)and LiNO_(3)exhibits enhanced ionic conductivity of 4.25×10^(-4)S cm^(-1)at 30℃ and flame retardancy.FEC and LiNO_(3) are conducive to form a stable solid electrolyte interphase(SEI)rich in Li_(3)N and LiF to improve interface stability.As expected,the dendrite-free Li‖BSIPE/PFN‖Li symmetric cell exhibits considerable cycling life over 1500 h.BSIPE/PFN significantly boosts the performance of LFP‖Li cell,which displays a capacity retention of 84.6%after 500 cycles.The BSIPE/PFN has promising applications in highsafety and high-performance lithium metal batteries.展开更多
Different reactive flame retardants have been extensively developed for vinyl ester resins(VERs),but very few of them can yield a flame-retardant resin that meets defined standards(e.g.UL-94 V-0 rating).In this work,p...Different reactive flame retardants have been extensively developed for vinyl ester resins(VERs),but very few of them can yield a flame-retardant resin that meets defined standards(e.g.UL-94 V-0 rating).In this work,phosphorous-containing 1-vinylimidazole salts(called VIDHP and VIDPP)were synthesized through the facile neutralization of the acid and 1-vinylimidazole.VIDHP and VIDPP were then applied as flame-retardant crosslinking agents of VERs,by which phosphorus-containing groups could be incorporated into the resin chain via ionic bonds.VIDHP/VER and VIDPP/VER showed a high curing activity and can be well cured in moderate temperatures.With 20 wt.%additions of VIDHP and VIDPP,VIDHP20/VER,and VIDPP20/VER presented a limiting oxygen index value of 29.7%and 28.4%,respectively,with the latter achieving a UL 94 V0 rating.In the cone calorimetric test,compared to the unmodified VERs,VIDPP20/VER exhibited large reductions in the peak heat release rate,total heat release rate,and total smoke release rate while VIDHP20/VER demonstrated comparatively inferior performance in terms of the heat release.VIDHP20/VER and VIDPP20/VER showed good thermal stability and presented a little lower glass transition temperature than the control sample.VIDPP with a low phosphorus oxidation state(+1)demonstrated high flame-retardant activities in the gaseous phase,whereas VIDHP with a high phosphorus oxidation state(+5)primarily exhibited efficacy in the condensed phase.展开更多
Flame-retardant mechanism of magnesium oxychloride （M OC） in EP was in-vestigated by limiting oxygen index （LOI）, XRD, SEM, TG-DTG and DSC. The results show that MOC performed well as an inorganic flame-retardant ...Flame-retardant mechanism of magnesium oxychloride （M OC） in EP was in-vestigated by limiting oxygen index （LOI）, XRD, SEM, TG-DTG and DSC. The results show that MOC performed well as an inorganic flame-retardant in EP. When the content of MOC is 50%, the LOI of EP reaches 29.6% and mass of residual char reaches 9.6%. The flame retarde mechanism of MOC is due to the synergies of diluting, cooling, catalyzing char forming and obstructing effects.展开更多
A new way to improve the tunnel fire protection by using flame-retarded porous asphalt pavement containing ATH powders was introduced. Based on the miniature burning test designed and conducted, the burning time and t...A new way to improve the tunnel fire protection by using flame-retarded porous asphalt pavement containing ATH powders was introduced. Based on the miniature burning test designed and conducted, the burning time and temperature of porous asphalt （PA） and flame-retarded porous asphalt （FRPA） were studied comparing with cement concrete pavement, dense-graded lIMA and SMA. Results of burning test and pavement performance test indicate that FRPA is appropriate and suitable as the pavement material of highway tunnel.展开更多
In order to reduce greenhouse gas emissions, developing flame retardants from bio-based resources has aroused extensive interest in recent years. In this work, we utilized furfural(biomass) and 9,10-dihydro-9-oxa-10-p...In order to reduce greenhouse gas emissions, developing flame retardants from bio-based resources has aroused extensive interest in recent years. In this work, we utilized furfural(biomass) and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide(DOPO) to synthesize a biobased co-curing agent(FGD) to combine with 4,4'-diaminodiphenyl methane(DDM) for obtaining a low-phosphorus loading flame-retardant epoxy thermosets. The introduction of FGD decreased the activation energy of the curing progress, enhanced the mechanical properties of the epoxy thermosets, and did not affect the glass transition temperature of the epoxy thermosets. EP-5.0 had a lower thermal degradation rate and a doubled char yield compared with EP-0. The phosphorus content of EP-5.0 was only 0.45 wt%, while EP-5.0 reached the UL-94 V-0 rating with a high LOI value of 32%. Compared with EP-0, the PHRR of EP-2.5 and EP-5.0 decreased by 22.3% and 31.3%, respectively. The SEM results showed that the addition of FGD made the char residues more uniform and denser, which could effectively prevent combustible volatiles from escaping from the degradation area to the flame area and isolate the heat transfer so that the epoxy thermosets had an excellent flame-retardant performance.展开更多
Phase change materials(PCMs)offer a promising solution to address the challenges posed by intermittency and fluctuations in solar thermal utilization.However,for organic solid-liquid PCMs,issues such as leakage,low th...Phase change materials(PCMs)offer a promising solution to address the challenges posed by intermittency and fluctuations in solar thermal utilization.However,for organic solid-liquid PCMs,issues such as leakage,low thermal conductivity,lack of efficient solar-thermal media,and flamma-bility have constrained their broad applications.Herein,we present an innova-tive class of versatile composite phase change materials(CPCMs)developed through a facile and environmentally friendly synthesis approach,leveraging the inherent anisotropy and unidirectional porosity of wood aerogel(nanowood)to support polyethylene glycol(PEG).The wood modification process involves the incorporation of phytic acid(PA)and MXene hybrid structure through an evaporation-induced assembly method,which could impart non-leaking PEG filling while concurrently facilitating thermal conduction,light absorption,and flame-retardant.Consequently,the as-prepared wood-based CPCMs showcase enhanced thermal conductivity(0.82 W m^(-1)K^(-1),about 4.6 times than PEG)as well as high latent heat of 135.5 kJ kg^(-1)(91.5%encapsula-tion)with thermal durability and stability throughout at least 200 heating and cooling cycles,featuring dramatic solar-thermal conversion efficiency up to 98.58%.In addition,with the synergistic effect of phytic acid and MXene,the flame-retardant performance of the CPCMs has been significantly enhanced,showing a self-extinguishing behavior.Moreover,the excellent electromagnetic shielding of 44.45 dB was endowed to the CPCMs,relieving contemporary health hazards associated with electromagnetic waves.Overall,we capitalize on the exquisite wood cell structure with unidirectional transport inherent in the development of multifunctional CPCMs,showcasing the operational principle through a proof-of-concept prototype system.展开更多
For solid polymer electrolytes(SPEs),improving their mechanical and electrochemical properties is the key to obtaining batteries with higher safety and higher energy density.Herein,a novel synergistic strategy propose...For solid polymer electrolytes(SPEs),improving their mechanical and electrochemical properties is the key to obtaining batteries with higher safety and higher energy density.Herein,a novel synergistic strategy proposed is preparing a 3D flame-retardant skeleton(3DPA)and adding nano-multifunctional fillers(Li-ILs@ZIF-8).In addition to providing mechanical support for the polyethylene oxide(PEO)matrix,3DPA also has further contributed to the system’s flame retardancy and further improved the safety.Simultaneously,the electrochemical performance is fully guaranteed by rigid Li-ILs@ZIF-8,which provides fast migration channels forLi^(+),reduces the crystallinity of PEO and effectively inhibits lithium dendrites.The limiting oxygen index of the optimal sample(PL3Z/PA)is as high as 20.5%,and the ionic conductivity reaches 2.89×10^(-4) and 0.91×10^(-3) S cm^(-1) at 25 and 55°C,respectively.The assembled Li|PL3Z/PA|Li battery can be cycled stably for more than 1000 h at a current density of 0.1 m A cm^(-2) without short circuit being pierced by lithium dendrites.The specific capacity of the LFP|PL3Z/PA|Li battery was 160.5 m Ah g^(-1) under a current density of 0.5 C,and the capacity retention rate was 90.0%after 300 cycles.展开更多
Lithium-sulfur(Li-S)batteries are one of the most promising modern-day energy supply systems because of their high theoretical energy density and low cost.However,the development of high-energy density Li-S batteries ...Lithium-sulfur(Li-S)batteries are one of the most promising modern-day energy supply systems because of their high theoretical energy density and low cost.However,the development of high-energy density Li-S batteries with high loading of flammable sulfur faces the challenges of electrochemical performance degradation owing to the shuttle effect and safety issues related to fire or explosion accidents.In this work,we report a three-dimensional(3D)conductive nitrogen-doped carbon foam supported electrostatic self-assembled MXene-ammonium polyphosphate(NCF-MXene-APP)layer as a heat-resistant,thermally-insulated,flame-retardant,and freestanding host for Li-S batteries with a facile and costeffective synthesis method.Consequently,through the use of NCF-MXene-APP hosts that strongly anchor polysulfides,the Li-S batteries demonstrate outstanding electrochemical properties,including a high initial discharge capacity of 1191.6 mA h g^(-1),excellent rate capacity of 755.0 mA h g^(-1)at 1 C,and long-term cycling stability with an extremely low-capacity decay rate of 0.12%per cycle at 2 C.More importantly,these batteries can continue to operate reliably under high temperature or flame attack conditions.Thus,this study provides valuable insights into the design of safe high-performance Li-S batteries.展开更多
Preparing both safe and high-performance lithium-ion batteries(LIBs) based on commonly used commercial electrolytes is highly desirable,yet challenging.To overcome the poor compatibility of conventional small-molecula...Preparing both safe and high-performance lithium-ion batteries(LIBs) based on commonly used commercial electrolytes is highly desirable,yet challenging.To overcome the poor compatibility of conventional small-molecular flame-retardants as electrolyte additives for safe LIBs with graphite anodes,in this study,we propose and design a novel low-cost flame-retardant oligomer that achieves an accurate and complete reconciliation of fire safety and electrochemical performance in LIBs.Owing to the integration of phosphonate units and polyethylene glycol(PEG) chains,this oligomer,which is a phosphonatecontaining PEG-based oligomer(PPO),not only endows commercial electrolytes with excellent flame retardancy but also helps stabilize the electrodes and Li-ion migration.Specifically,adding 15 wt% of PPO can reduce 70% of the self-extinguishing time and 54% of total heat release for commercial electrolytes.Moreover,LiFePO_(4)/lithium and graphite/lithium cells as well as LiFePO_(4)/graphite pouch full cells exhibit good long-term cycling stability.展开更多
Used as flame returdant of tunnel asphalt pavement, organic bromides produce a large amount of poisons and smoke in construction and flame retardation stage. The alkaline filler was found to replace mineral filler, ...Used as flame returdant of tunnel asphalt pavement, organic bromides produce a large amount of poisons and smoke in construction and flame retardation stage. The alkaline filler was found to replace mineral filler, and the flame- retarded asphalt mixtures were produced. Experimental results show that these asphalt mixtures are smoke restrained ; the performances and construction technology of asphalt pavement are not influenced; also the alkaline filler is of low-price. So this kind of flame-retarded asphalt mixtures is suitable for tunnel patement.展开更多
Flame-retardant polymer electrolytes(FRSPEs)are attractive due to their potential for fundamentally settling the safety issues of liquid electrolytes.However,the current FRSPEs have introduced large quantity of flame-...Flame-retardant polymer electrolytes(FRSPEs)are attractive due to their potential for fundamentally settling the safety issues of liquid electrolytes.However,the current FRSPEs have introduced large quantity of flame-retardant composition which cannot conduct lithium ions,thus decreasing the Li-ion conductivity.Here,we synthesize a novel liquid monomer 2-((bis((2-oxo-1,3-dioxolan-4-yl)methoxy)phosphoryl)oxy)ethyl acrylate(BDPA)for preparing FRSPE by in-situ polymerization,in which PBDPA polymer can not only conduct lithium ions,but also prevent burning.The prepared FRSPE demonstrated outstanding flame-retardant property,favorable lithium-ion conductivity of 5.65×10^(-4) S cm^(-1) at ambient temperature,and a wide electrochemical window up to 4.5 V.Moreover,the Li/in-situ FRSPE/S@pPAN cell exhibited favorable electrochemical performances.We believe that this work provides an effective strategy for establishing high-performance fireproof quasi-solid-state battery system.展开更多
Six new optically active and flame-retardant poly（amide-imide）s PAls 5a-5f containing phosphine oxide moiety as a flame-retardant unit in the main chain were synthesized from direct polycondensation reaction of six ...Six new optically active and flame-retardant poly（amide-imide）s PAls 5a-5f containing phosphine oxide moiety as a flame-retardant unit in the main chain were synthesized from direct polycondensation reaction of six chiral N,N＇-（pyromellitoyl）-bis-L-amino acid 3a-3f with bis（3-aminophenyl）phenyl phosphine oxide 4 in a medium consisting of N-methyl-2-pyrrolidone （NMP）, triphenyl phosphite （TPP）, calcium chloride （CaCl2） and pyridine. The polymerization reactions produced a series of optically active poly（amide-imide）s with good yield and good inherent viscosity of 0.34-0.70 dLg^-1. The resulted polymers were fully characterized by means of FTIR and ^1H-NMR spectroscopy, gel permeation chromatography （GPC）, elemental analyses, inherent viscosity and solubility tests. Thermal properties and flameretardant behavior of the PAIs 5a-5f were investigated using thermal gravimetric analysis （TGA and DTG） and limiting oxygen index （LOI）. Data obtained by thermal analysis （TGA and DTG） revealed that these polymers showed good thermal stability. Furthermore, high char yield in TGA and good LOI values indicated that the resulting polymers were capable of exhibiting good flame retardant properties. N,N＇-（pyromellitoyl）-bis-L-amino acids 3a-3f were prepared in quantitative yields by the condensation reaction of pyromellitic dianhydride （1,2,4,5-benzenetetracarboxylicacid-1,2,4,5-dianhydride） 1 with L-alanine 2a, L-valine 2b, L-leucine 2c, L-isoleucine 2d, L-phenyl alanine 2e and L-2-aminobutyric acid 2f in acetic acid solution.展开更多
基金the National Natural Science Foundation of China(No.22268025)the Science and Tech-nology Program of Guangzhou(No.2024A04J3710)the Sci-entific and Technological Innovation Strategy Program of Guang-dong Province:Guangdong-Hong Kong-Macao Technology Cooper-ation Funding Scheme(No.2022A0505030026).
文摘Contemporary industrial sectors are experiencing a growing imperative for coatings that exhibit a multi-tude of functions.In this study,PBP-Ce(Ш)nanosheets,characterized by robust structural stability,were synthesized using a one-pot method and incorporated into waterborne epoxy resin(WEP)to formu-late nanocomposite coatings.The findings demonstrate that the coating,containing 0.6 wt.%PBP-Ce(Ш)nanosheets,exhibits superb anti-corrosion,flame-retardant,and wear-resistant properties.Upon 42 days of 3.5%NaCl solution immersion,the fb of the 6-PBTC coating was a mere 3.55 Hz,significantly lower than the 309.51 Hz measured for the pure WEP coating.Furthermore,the Peak heat release rate(PHRR)of the microscale combustion calorimeter(MCC)and the wear rate of the 6-PBTC coating were reduced by 41.63%and 84.65%,respectively,in comparison to the pure WEP coating.This work not only delves into the utilization of BP nanosheets but also presents a viable solution for advancing the development of multifunctional coatings.
基金Funded by the National Key Research and Development Program of China(No.2016YFD0200404)the Sichuan Science and Technology Program(No.2018RZ0145)the National“Double First-Rate”Strategic Plan of Sichuan University,China(No.2030704401004)。
文摘A halogen-free flame-retardant (hydroquinone bis (N,N’-diarylphosphoramidate),4N-HDP) containing phosphorus-nitrogen was synthesized.Its structure was characterized by infrared spectroscopy (IR),nuclear magnetic resonance (^(1)H-NMR and^(31)P-NMR).Thermogravimetric analysis (TG),limiting oxygen index (LOI),UL-94 vertical burning test (UL-94),thermogravimetric-infrared instrument (TG-IR) and scanning electron microscopy (SEM) were used to compare the flame-retarding performance and mechanism of hydroquinone bis (diphenyl phosphate) (HDP) and 4N-HDP.TG,IR and TG-IR were used for comparative analysis,indicating that both HDP and 4N-HDP are flame-retardants,and the gas phase and condensed phase act synergistically.In the pyrolysis process,it is divided into two steps:the first step is the breakage of large molecules to small molecules;the second step is the gasification and carbonization of small molecules,and eventually produces phosphate ester and non-flammable gases.Through the comparison of various results,it could be found that 4N-HDP has better flame-retarding performance compared to HDP in the composite with polycarbonate (PC).
文摘The effect of potash as a nondurable finish on the flammability of 100% cotton fabric （plain 180 g/m^2） was investigated. The bone-drled weighed fabrics were dipped into suitable concentrations of potash, with a volume of 100 mL at 20-2℃. The impregnation was followed by means of squeeze rolls and drying at 110 ℃. The samples were then reweighed with analytical precision. After conditioning overnight by using our ＂vertical flame tester＂ the optimum add-on values to impart flame-retardancy to cotton fabric was determined and expressed by 0.80 g of potash per 100 g fabric to be an efficient addition. Thermogravimetric analysis of pure cotton, treated cotton with potash at its optimum efficiency for donation of flame-retardancy into cotton fabric was fulfilled and the thermograms were compared and commented. The effectiveness of this hydroxide was attributed to the heat dissipation by the remaining consumed material during the combustion. The results obtained are in favor of ＂Dust or Wall Effect Theory＂.
文摘We have investigated the effect of zinc oxide as a photocatalyst and durable flame-retardant on cellulosic fibers. Zinc oxide nanocrystals were successfully synthesized and deposited onto cellulosic fibers using sol-gel process at low temperature. The samples were characterized by means of several techniques such as scanning electron microscopy, transmission electron microscopy, diffuse reflectance spectroscopy, X-ray diffraction and thermogra- vimetric analysis. The photocatalytic activity was tested by measuring the photodegradation of methylene blue under UV-Vis illumination. Moreover, flame-retardancy was tested by vertical flame spread test. The optimum add-on value for donating flame-retardancy onto cellulosic fabric was obtained to be in the range of 15.24 to 23.20 g of the ZnO per 100 g of fabric. Thermogravimetric analysis of pure and flame-retarded samples were accomplished and discussed. The results obtained are in agreement with Wall effect theory and Coating theory. The originality of this work on introducing photoactive flame-retarded fibers is highly valuable for industrial implementation.
基金supported by the National Natural Science Foundation of China(Nos.51732011,U1932213,and 22005290)the National Basic Research Program of China(No.2021YFA0715700)+4 种基金the National Key Research and Development Program of China(No.2018YFE0202201)Science and Technology Major Project of Anhui Province(No.201903a05020003)the University Synergy Innovation Program of Anhui Province(No.GXXT-2019-028)the Hefei Municipal Natural Science Foundation(No.2021024).Z.Y.M.acknowledges the funding support by China Postdoctoral Science Foundation(No.2021TQ0317)the Fundamental Research Funds for the Central Universities(No.WK2060000049).
文摘Compared to natural woods,synthetic woods have superior mechanical stability,thermal insulation,and flame retardancy owing to their hierarchically cellular microstructures and intrinsic advantages of the thermosetting matrix.Increasing the long-time fire resistance is very important to the practical application.In this study,we present a novel coating strategy by a vacuum-assisted sonication technique(sonocoating)with a rectorite nanosheet dispersion to create a uniform nanocoating on the channel walls of synthetic wood.Owing to ultrasonic energy and vacuum pressure,the nanosheet dispersion can penetrate deep down to form a layered nanocoating on the channel surface.The coated synthetic woods can withstand fire(400-600℃)for more than 10 min with 62%mass retainment,surpassing uncoated synthetic woods and natural woods.Therefore,as a lightweight and strong composite with enhanced flame-retardant performance,the coated synthetic woods have huge potential applications in safe and energy-efficient buildings.
基金supported by the National Science Fund for Distinguished Young Scholars(No.T2225004)National Natural Science Foundation of China(No.52373092)Shccig-Qinling Program.
文摘The alternating copolymer of CO_(2) with epoxide is a green plastic that can efficiently transform CO_(2) into valuable chemicals. Despite the significant advances made, the restricted practical application of CO_(2)-sourced polycarbonates due to their lack of functionality has hindered field development. We successfully demonstrated the flame retardancy of poly(chloropropylene carbonate) (PCPC), a perfectly alternating copolymer of epichlorohydrin (ECH) and CO_(2). This was prepared at a 200-gram scale using a high-efficacy tetranuclear organoborane catalyst. PCPC’s excellent flame-retardant performance has been proven by both the vertical combustion test (UL94 V-0) and the limiting oxygen index (LOI) value (29.1%). The underlaid flame-retardant mechanism of PCPC was clearly elucidated. As a result, we confirmed that the generated cyclic carbonates and concurrently released flame-retardant chlorine radicals, hydrogen chloride, and CO_(2) during combustion render PCPC an excellent flame retardant. Furthermore, we investigated the practicability of PCPC as a halogen-rich polymeric flame retardant by blending it with commercial bisphenol A polycarbonate (BPA-PC). PCPC upgraded the flame retardancy rating of BPA polycarbonate from V-2 to V-0 even with a mere 1 wt% addition. It is our hope that this result will prove useful in future developments of advanced CO_(2)-sourced polymeric materials.
基金supported by the National Key Research and Development Program of China(No.2021YFB3701100)the Applied Basic Research Program Project of Liaoning Province of China(No.2023020253-JH2/1016)the Key Research and Development Plan of Shanxi Province(No.202102050201005)。
文摘Poor formability is a key problem that limits the application of flame-retardant Mg-Al-Ca based alloys at room temperature.In this study,we present a new Mg-6Al-3Ca-0.4Mn-2Zn(wt%)alloy which exhibits excellent flame-retardant performance and excellent formability.Due to the high Ca content,the Mg-6Al-3Ca-0.4Mn-2Zn(wt%)alloy does not burn at 1065℃.The formability of the alloys is measured using a three-point bending test,and the Mg-6Al-3Ca-0.4Mn-2Zn(wt%)alloy shows excellent formability,with a significant increase in bending displacement from 7.1 mm to 23.8 mm compared to the Mg-6Al-3Ca-0.4Mn(wt%)alloy.The combined effect of the weakened basal texture,the reduction of twins and the plastically deformable Al2Ca phase particles ensures good formability of the Mg-6Al-3Ca-0.4Mn-2Zn(wt%)alloy.The dynamic recrystallization mechanisms of the alloys have been analyzed,and the promotion of dynamic recrystallization by the PSN mechanism is responsible for the weakened basal texture and the reduction of twins in the Mg-6Al-3Ca-0.4Mn-2Zn(wt%)alloy.The new Mg alloy is attractive for industrial applications due to its excellent flame-retardant performance and formability.
基金supported by the National Key Research and Development Program of China(No.2021YFB3701100)the Applied Basic Research Program Project of Liaoning Province,China(No.2023020253-JH2/1016)the Key Research and Development Plan of Shanxi Province,China(No.202102050201005).
文摘The effect of extrusion temperature on the dynamic recrystallization behavior and mechanical properties of the flame-retardant Mg−6Al−3Ca−1Zn−1Sn−Mn(wt.%)alloy was investigated.The observed dynamic recrystallization mechanisms in the alloy include continuous dynamic recrystallization(CDRX)and particle simulated nucleation(PSN)during hot extrusion.A significant increase in yield strength,from 218 to 358 MPa,representing a 140 MPa increase,is achieved by decreasing the extrusion temperature.The strengthening mechanisms were analyzed quantitatively,with the enhanced strength primarily attributed to grain boundary and dislocation strengthening.The plasticity mechanism was analyzed qualitatively,and the increase in the volume fraction of unDRXed grains caused by the decrease in extrusion temperature leads to an increase in the number of{1012}tensile twins during the tensile deformation,resulting in a reduction in plasticity.
基金supported by the National Natural Science Foundation of China(22179149,22075329,51573215,and 21978332)Research and Development Project of Henan Academy Sciences China(232018002)。
文摘Single ion gel polymer electrolyte has the advantages of high Li^(+)conductivity and dendrite mitigation.However,the addition of organic solvent makes the electrolyte flammable,posing serious safety hazards.Herein,we report a flame-retard ant cross-linked sp^(3)boron-based single-ion gel polymer electrolyte(BSIPE).BSIPE was prepared by a simple one-step photoinitiated in situ thiol-ene click reaction.Due to the boron-based anions being immobilized in the cross-linking network,the developed BSIPE/PFN exhibits a high t_(Li^(+))(0.87),which can mitigate concentration polarization phenomenon and suppress the growth of lithium dendrites.BSIPE/PFN plasticized with triethyl phosphate(TEP),fluoroethylene carbonate(FEC)and LiNO_(3)exhibits enhanced ionic conductivity of 4.25×10^(-4)S cm^(-1)at 30℃ and flame retardancy.FEC and LiNO_(3) are conducive to form a stable solid electrolyte interphase(SEI)rich in Li_(3)N and LiF to improve interface stability.As expected,the dendrite-free Li‖BSIPE/PFN‖Li symmetric cell exhibits considerable cycling life over 1500 h.BSIPE/PFN significantly boosts the performance of LFP‖Li cell,which displays a capacity retention of 84.6%after 500 cycles.The BSIPE/PFN has promising applications in highsafety and high-performance lithium metal batteries.
基金supported by the National Natural Science Foundation of China(Grant Nos.51991351 and51903132)the Young Elite Scientist Sponsorship Program by CAST(No.2022QNRC001).
文摘Different reactive flame retardants have been extensively developed for vinyl ester resins(VERs),but very few of them can yield a flame-retardant resin that meets defined standards(e.g.UL-94 V-0 rating).In this work,phosphorous-containing 1-vinylimidazole salts(called VIDHP and VIDPP)were synthesized through the facile neutralization of the acid and 1-vinylimidazole.VIDHP and VIDPP were then applied as flame-retardant crosslinking agents of VERs,by which phosphorus-containing groups could be incorporated into the resin chain via ionic bonds.VIDHP/VER and VIDPP/VER showed a high curing activity and can be well cured in moderate temperatures.With 20 wt.%additions of VIDHP and VIDPP,VIDHP20/VER,and VIDPP20/VER presented a limiting oxygen index value of 29.7%and 28.4%,respectively,with the latter achieving a UL 94 V0 rating.In the cone calorimetric test,compared to the unmodified VERs,VIDPP20/VER exhibited large reductions in the peak heat release rate,total heat release rate,and total smoke release rate while VIDHP20/VER demonstrated comparatively inferior performance in terms of the heat release.VIDHP20/VER and VIDPP20/VER showed good thermal stability and presented a little lower glass transition temperature than the control sample.VIDPP with a low phosphorus oxidation state(+1)demonstrated high flame-retardant activities in the gaseous phase,whereas VIDHP with a high phosphorus oxidation state(+5)primarily exhibited efficacy in the condensed phase.
基金Funded by the Defense Preresearch Project of the Eleventh-Five-Year-Plan of China (No. 51312040404)
文摘Flame-retardant mechanism of magnesium oxychloride （M OC） in EP was in-vestigated by limiting oxygen index （LOI）, XRD, SEM, TG-DTG and DSC. The results show that MOC performed well as an inorganic flame-retardant in EP. When the content of MOC is 50%, the LOI of EP reaches 29.6% and mass of residual char reaches 9.6%. The flame retarde mechanism of MOC is due to the synergies of diluting, cooling, catalyzing char forming and obstructing effects.
基金Hi-tech Research and Development Program of China (863 Program of China) (No.2006AA11Z117)
文摘A new way to improve the tunnel fire protection by using flame-retarded porous asphalt pavement containing ATH powders was introduced. Based on the miniature burning test designed and conducted, the burning time and temperature of porous asphalt （PA） and flame-retarded porous asphalt （FRPA） were studied comparing with cement concrete pavement, dense-graded lIMA and SMA. Results of burning test and pavement performance test indicate that FRPA is appropriate and suitable as the pavement material of highway tunnel.
基金financial support from the National Natural Science Foundation of China (No. 22075265)the Youth Innovation Promotion Association of the Chinese Academy of Sciences (No. 2021459)。
文摘In order to reduce greenhouse gas emissions, developing flame retardants from bio-based resources has aroused extensive interest in recent years. In this work, we utilized furfural(biomass) and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide(DOPO) to synthesize a biobased co-curing agent(FGD) to combine with 4,4'-diaminodiphenyl methane(DDM) for obtaining a low-phosphorus loading flame-retardant epoxy thermosets. The introduction of FGD decreased the activation energy of the curing progress, enhanced the mechanical properties of the epoxy thermosets, and did not affect the glass transition temperature of the epoxy thermosets. EP-5.0 had a lower thermal degradation rate and a doubled char yield compared with EP-0. The phosphorus content of EP-5.0 was only 0.45 wt%, while EP-5.0 reached the UL-94 V-0 rating with a high LOI value of 32%. Compared with EP-0, the PHRR of EP-2.5 and EP-5.0 decreased by 22.3% and 31.3%, respectively. The SEM results showed that the addition of FGD made the char residues more uniform and denser, which could effectively prevent combustible volatiles from escaping from the degradation area to the flame area and isolate the heat transfer so that the epoxy thermosets had an excellent flame-retardant performance.
基金funding from the National Natural Science Foundation of China(No.22268025)China Postdoctoral Science Foundation(NO.2022MD713757)+2 种基金Yunnan Provincial Postdoctoral Science Foundation(NO.34Y2022)Yunnan Province Joint Special Project for Enterprise Fundamental Research and Applied Basic Research(No.202101BC070001-016)Guangdong Basic and Applied Basic Research Foundation(No.2023A1515011985).
文摘Phase change materials(PCMs)offer a promising solution to address the challenges posed by intermittency and fluctuations in solar thermal utilization.However,for organic solid-liquid PCMs,issues such as leakage,low thermal conductivity,lack of efficient solar-thermal media,and flamma-bility have constrained their broad applications.Herein,we present an innova-tive class of versatile composite phase change materials(CPCMs)developed through a facile and environmentally friendly synthesis approach,leveraging the inherent anisotropy and unidirectional porosity of wood aerogel(nanowood)to support polyethylene glycol(PEG).The wood modification process involves the incorporation of phytic acid(PA)and MXene hybrid structure through an evaporation-induced assembly method,which could impart non-leaking PEG filling while concurrently facilitating thermal conduction,light absorption,and flame-retardant.Consequently,the as-prepared wood-based CPCMs showcase enhanced thermal conductivity(0.82 W m^(-1)K^(-1),about 4.6 times than PEG)as well as high latent heat of 135.5 kJ kg^(-1)(91.5%encapsula-tion)with thermal durability and stability throughout at least 200 heating and cooling cycles,featuring dramatic solar-thermal conversion efficiency up to 98.58%.In addition,with the synergistic effect of phytic acid and MXene,the flame-retardant performance of the CPCMs has been significantly enhanced,showing a self-extinguishing behavior.Moreover,the excellent electromagnetic shielding of 44.45 dB was endowed to the CPCMs,relieving contemporary health hazards associated with electromagnetic waves.Overall,we capitalize on the exquisite wood cell structure with unidirectional transport inherent in the development of multifunctional CPCMs,showcasing the operational principle through a proof-of-concept prototype system.
基金supported by the National Key Research and Development Program of China(Grant No.2017YFA0204600)the National Natural Science Foundation of China(Grant No.5210021666)the Key R&D and Promotion Projects of Henan Province(Grant No.212102310016)。
文摘For solid polymer electrolytes(SPEs),improving their mechanical and electrochemical properties is the key to obtaining batteries with higher safety and higher energy density.Herein,a novel synergistic strategy proposed is preparing a 3D flame-retardant skeleton(3DPA)and adding nano-multifunctional fillers(Li-ILs@ZIF-8).In addition to providing mechanical support for the polyethylene oxide(PEO)matrix,3DPA also has further contributed to the system’s flame retardancy and further improved the safety.Simultaneously,the electrochemical performance is fully guaranteed by rigid Li-ILs@ZIF-8,which provides fast migration channels forLi^(+),reduces the crystallinity of PEO and effectively inhibits lithium dendrites.The limiting oxygen index of the optimal sample(PL3Z/PA)is as high as 20.5%,and the ionic conductivity reaches 2.89×10^(-4) and 0.91×10^(-3) S cm^(-1) at 25 and 55°C,respectively.The assembled Li|PL3Z/PA|Li battery can be cycled stably for more than 1000 h at a current density of 0.1 m A cm^(-2) without short circuit being pierced by lithium dendrites.The specific capacity of the LFP|PL3Z/PA|Li battery was 160.5 m Ah g^(-1) under a current density of 0.5 C,and the capacity retention rate was 90.0%after 300 cycles.
基金supported by the National Research Foundation of Korea(NRF-2021R1A2C1008272)supported by the Institute of Information&communications Technology Planning&Evaluation(IITP)grant funded by the Korean government(MSIT)(No.2021-0-00259,Development of a Fast Wireless Charging System for Portable Terminals with improved heat dissipation and shielding performance)supported by the Applied Basic Research Program of Changzhou City(CJ20220030).
文摘Lithium-sulfur(Li-S)batteries are one of the most promising modern-day energy supply systems because of their high theoretical energy density and low cost.However,the development of high-energy density Li-S batteries with high loading of flammable sulfur faces the challenges of electrochemical performance degradation owing to the shuttle effect and safety issues related to fire or explosion accidents.In this work,we report a three-dimensional(3D)conductive nitrogen-doped carbon foam supported electrostatic self-assembled MXene-ammonium polyphosphate(NCF-MXene-APP)layer as a heat-resistant,thermally-insulated,flame-retardant,and freestanding host for Li-S batteries with a facile and costeffective synthesis method.Consequently,through the use of NCF-MXene-APP hosts that strongly anchor polysulfides,the Li-S batteries demonstrate outstanding electrochemical properties,including a high initial discharge capacity of 1191.6 mA h g^(-1),excellent rate capacity of 755.0 mA h g^(-1)at 1 C,and long-term cycling stability with an extremely low-capacity decay rate of 0.12%per cycle at 2 C.More importantly,these batteries can continue to operate reliably under high temperature or flame attack conditions.Thus,this study provides valuable insights into the design of safe high-performance Li-S batteries.
基金supported by the National Natural Science Foundation of China (51773134, U19A2095)the Sichuan Science and Technology Program (2019YFH0112)+2 种基金the Fundamental Research Funds for the Central UniversitiesInstitutional Research Fund from Sichuan University (2021SCUNL201)the 111 Project (B20001)。
文摘Preparing both safe and high-performance lithium-ion batteries(LIBs) based on commonly used commercial electrolytes is highly desirable,yet challenging.To overcome the poor compatibility of conventional small-molecular flame-retardants as electrolyte additives for safe LIBs with graphite anodes,in this study,we propose and design a novel low-cost flame-retardant oligomer that achieves an accurate and complete reconciliation of fire safety and electrochemical performance in LIBs.Owing to the integration of phosphonate units and polyethylene glycol(PEG) chains,this oligomer,which is a phosphonatecontaining PEG-based oligomer(PPO),not only endows commercial electrolytes with excellent flame retardancy but also helps stabilize the electrodes and Li-ion migration.Specifically,adding 15 wt% of PPO can reduce 70% of the self-extinguishing time and 54% of total heat release for commercial electrolytes.Moreover,LiFePO_(4)/lithium and graphite/lithium cells as well as LiFePO_(4)/graphite pouch full cells exhibit good long-term cycling stability.
文摘Used as flame returdant of tunnel asphalt pavement, organic bromides produce a large amount of poisons and smoke in construction and flame retardation stage. The alkaline filler was found to replace mineral filler, and the flame- retarded asphalt mixtures were produced. Experimental results show that these asphalt mixtures are smoke restrained ; the performances and construction technology of asphalt pavement are not influenced; also the alkaline filler is of low-price. So this kind of flame-retarded asphalt mixtures is suitable for tunnel patement.
基金financially supported by the National Natural Science Foundation of China(Nos.21773154 and U1705255)。
文摘Flame-retardant polymer electrolytes(FRSPEs)are attractive due to their potential for fundamentally settling the safety issues of liquid electrolytes.However,the current FRSPEs have introduced large quantity of flame-retardant composition which cannot conduct lithium ions,thus decreasing the Li-ion conductivity.Here,we synthesize a novel liquid monomer 2-((bis((2-oxo-1,3-dioxolan-4-yl)methoxy)phosphoryl)oxy)ethyl acrylate(BDPA)for preparing FRSPE by in-situ polymerization,in which PBDPA polymer can not only conduct lithium ions,but also prevent burning.The prepared FRSPE demonstrated outstanding flame-retardant property,favorable lithium-ion conductivity of 5.65×10^(-4) S cm^(-1) at ambient temperature,and a wide electrochemical window up to 4.5 V.Moreover,the Li/in-situ FRSPE/S@pPAN cell exhibited favorable electrochemical performances.We believe that this work provides an effective strategy for establishing high-performance fireproof quasi-solid-state battery system.
文摘Six new optically active and flame-retardant poly（amide-imide）s PAls 5a-5f containing phosphine oxide moiety as a flame-retardant unit in the main chain were synthesized from direct polycondensation reaction of six chiral N,N＇-（pyromellitoyl）-bis-L-amino acid 3a-3f with bis（3-aminophenyl）phenyl phosphine oxide 4 in a medium consisting of N-methyl-2-pyrrolidone （NMP）, triphenyl phosphite （TPP）, calcium chloride （CaCl2） and pyridine. The polymerization reactions produced a series of optically active poly（amide-imide）s with good yield and good inherent viscosity of 0.34-0.70 dLg^-1. The resulted polymers were fully characterized by means of FTIR and ^1H-NMR spectroscopy, gel permeation chromatography （GPC）, elemental analyses, inherent viscosity and solubility tests. Thermal properties and flameretardant behavior of the PAIs 5a-5f were investigated using thermal gravimetric analysis （TGA and DTG） and limiting oxygen index （LOI）. Data obtained by thermal analysis （TGA and DTG） revealed that these polymers showed good thermal stability. Furthermore, high char yield in TGA and good LOI values indicated that the resulting polymers were capable of exhibiting good flame retardant properties. N,N＇-（pyromellitoyl）-bis-L-amino acids 3a-3f were prepared in quantitative yields by the condensation reaction of pyromellitic dianhydride （1,2,4,5-benzenetetracarboxylicacid-1,2,4,5-dianhydride） 1 with L-alanine 2a, L-valine 2b, L-leucine 2c, L-isoleucine 2d, L-phenyl alanine 2e and L-2-aminobutyric acid 2f in acetic acid solution.
