By using 6,6-((sulfonylbis(4,1-phenylene)bis(azanediyl))bis(thiophen-2-ylm-ethylene))bis6H-di-benzo[c,e][1,2]oxaphosphinine 6-oxide(DOPO-N)as phosphorus-nitrogen flame retardant,the polyurea(PUA)with flame retardant p...By using 6,6-((sulfonylbis(4,1-phenylene)bis(azanediyl))bis(thiophen-2-ylm-ethylene))bis6H-di-benzo[c,e][1,2]oxaphosphinine 6-oxide(DOPO-N)as phosphorus-nitrogen flame retardant,the polyurea(PUA)with flame retardant properties(PUA/DOPO-N)was prepared.In addition,organically modified montmorillonite(OMMT)and magnesium hydroxide(MH)were used as co-effectors respectively,and the flame retardant PUA(PUA/DOPO-N/OMMT and PUA/DOPO-N/MH)were also prepared.Thermal properties,flame retardant properties,flame retardant mechanism and mechanical properties of PUA/DOPO-N,PUA/DOPO-N/OMMT and PUA/DOPO-N/MH were investigated by thermogravimetric(TG)analysis,limiting oxygen index(LOI),UL 94,cone calorimeter test,scanning electron microscopy(SEM),and tensile test.The results show that the LOI value of PUA/20%DOPO-N,PUA/18%DOPO-N/2%OMMT and PUA/15%DOPO-N/5%MH are 27.1%,27.7%,and 28.3%,respectively,and UL 94 V-0 rating is attained.Compared with PUA,the peak heat release rate(pk-HRR),total heat release(THR)and average effective heat combustion(av-EHC)of PUA/20%DOPO-N,PUA/18%DOPO-N/2%OMMT and PUA/15%DOPO-N/5%MH decrease significantly.SEM results indicate that the residual chars of PUA/20%DOPO-N,PUA/18%DOPO-N/2%OMMT and PUA/15%DOPO-N/5%MH are completer and more compact.The complex of DOPO-N/OMMT and DOPO-N/MH have synergistic flame retardancy.The mechanical properties of PUA can be improved by the addition of DOPO-N,DOPO-N/OMMT and DOPO-N/MH,respectively.The insulation performance test shows that the volume resistivity of PUA/20%DOPO-N is 6.25×10^(16)Ω.cm.Furthermore,by using modified boron nitride(MBN)as heat dissipating material,the complex of PUA/MBN was prepared,and the thermal conductivity of PUA/MBN was investigated.The thermal conductivity of PUA/8%MBN complex coating at room temperature is 0.166 W/(M·K),which is a 163%improvement over pure PUA.展开更多
Flame retardant coatings are functional materials that can serve as decorative and protec-tive substrates in the event of a fire.Flame retardant coatings generally consist of two parts:a base material and a flame reta...Flame retardant coatings are functional materials that can serve as decorative and protec-tive substrates in the event of a fire.Flame retardant coatings generally consist of two parts:a base material and a flame retardant agent.A detailed introduction was given to the development of flame retardant coatings in recent years and the flame retardants used in flame retardant coatings.Flame retardants mainly include halogen flame retar-dants,phosphorus nitrogen flame retardants,expansion flame retardants,biomass flame retardants,and graphene flame retardants.The application of flame retardant coatings in the fields of epoxy resin,polyurethane,etc.was elaborated.In addition,the application of new biomass flame retardants and graphene flame retardants was introduced,and the future development of flame retardant coatings and flame retardants was described.展开更多
Aluminum hypophosphite microspheres(AHP) were synthesized by hydrothermal method using NaH2PO2·H2O and AlCl3·6H2O as raw materials, and then the AHP microspheres were polymerized by surface polymerization of...Aluminum hypophosphite microspheres(AHP) were synthesized by hydrothermal method using NaH2PO2·H2O and AlCl3·6H2O as raw materials, and then the AHP microspheres were polymerized by surface polymerization of micro-nanospheres with cyclic cross-linked poly(cyclotriphosphazene-co-4,4'-sulfonyldiphenol)(PZS). A new organic-inorganic poly(phosphonitrile)-modified aluminum hypophosphite microspheres(PZS-AHP) were synthesized by encapsulation and applied to flame retardant thermoplastic polyurethane(TPU). The microstructure and chemical composition of the PZS-AHP microsphere were characterized by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy and X-ray spectroscopy. The thermal stability of PZS-AHP microsphere was explored with thermogravimetric analysis. Thermogravimetric data indicate that the PZS-AHP microspheres have excellent thermal stability. The thermal and flame-retarding properties of the TPU composites were evaluated by thermogravimetric(TG), limited oxygen index tests(LOI), and cone calorimeter test(CCT). The TPU composite achieved vertical burning(UL-94) V-0 grade and LOI value reached 29.2% when 10 wt% PZS-AHP was incorporated. Compared with those of pure TPU, the peak heat release rate(pHRR) and total heat release(THR) of TPU/10%PZS-AHP decreased by 82.2% and 42.5%, respectively. The results of CCT indicated that PZS-AHP microsphere could improve the flame retardancy of TPU composites.展开更多
Polyamide 6 (PA6) was employed as a charring agent of intumescent flame retardant (IFR) to improve the flame retardancy of ethylene-vinyl acetate copolymer (EVA). Different processing procedures were used to regulate ...Polyamide 6 (PA6) was employed as a charring agent of intumescent flame retardant (IFR) to improve the flame retardancy of ethylene-vinyl acetate copolymer (EVA). Different processing procedures were used to regulate the localization of IFR in the EVA matrix. Localizations in which IFR was dispersed in the PA6phase or in the EVA phase were prepared. The effect of the localization of IFR on the flame retardancy of EVA was investigated. The limited oxygen index (LOI), vertical burning (UL 94) and cone calorimeter test (CCT)showed that the localization of IFR in the EVA matrix exhibited a remarkable influence on the flame retardancy.Compared with EVA/IFR, a weak improvement in the flame retardancy was observed in the EVA/PA6/IFR blend withthe localization of IFR in the PA6 phase. When IFR was regulated from the PA6 phase to the EVA matrix,a remarkable increase in the flame retardancy was exhibited. The LOI was increased from 27.8%to 32.7%, and the UL 94 vertical rating was increased from V-2 to V-0. Moreover, an approximately 41.36%decrease in the peak heat release rate was exhibited. A continuous and compact intumescent charring layer that formed in the blends with the localization of IFR in the EVA matrix should be responsible for its excellent flame retardancy.展开更多
A flame retardant containing multiple antiflaming elements usually exhibits high-efficient flame retardancy. Here, a novel P/N/Si-containing ammonium polyphosphate derivative(APTES-APP) is synthesized from ammonium po...A flame retardant containing multiple antiflaming elements usually exhibits high-efficient flame retardancy. Here, a novel P/N/Si-containing ammonium polyphosphate derivative(APTES-APP) is synthesized from ammonium polyphosphate(APP) and silane coupling agent(3-aminopropyl)triethoxysilane(APTES)via cation exchange, which is quite different in the chemical structure from APTES-modified APP for retaining silicon hydroxyls. APTES-APP is highly efficient for the epoxy resin. 8%(mass) APTES-APP imparts excellent flame retardancy to the epoxy resin, with a V-0 rating at the UL-94 test(1.6 mm)and an LOI value of 26%(vol). The peak heat release rate and total smoke production of the flameretardant epoxy resin are decreased by 68.1% and 31.3%, respectively. The synergy of P/N/Si contributes to the well-expanded char residue with a strong and dense surface layer, which is a very good barrier against heat and mass transfer. Besides, there is no significant deterioration in the mechanical properties of flame-retardant epoxy resin thanks to silicon hydroxyls forming hydrogen bonds with epoxy molecules. Meanwhile, other molecules can be grafted onto APTES-APP via these silicon hydroxyls, if needed.Briefly, this work has developed a new strategy for amino silane as flame retardants. In conjunction with a low-cost and simple preparation method, APTES-APP has a promising prospect in the high-performance flame-retardant epoxy.展开更多
As one of the most popular research directions,the application safety of battery technology has attracted more and more attention,researchers in academia and industry are making efforts to develop safer flame retardan...As one of the most popular research directions,the application safety of battery technology has attracted more and more attention,researchers in academia and industry are making efforts to develop safer flame retardant battery.The battery consists of electrolyte,separator,electrode and shell,the traditional flame retardant method of battery is to modify the components to improve its flame safety.In this review,varied types of battery flame retardant technology are initially described,including the type of flame-retardants,flame retardant behaviors and flame retardant mechanisms.Latest research progress of various battery flame retardant technologies is summarized.Typical flame retardant approaches and important properties of flame retardant battery are reviewed as well.In addition,the current main challenges of the battery flame retardant technology in both academics and the industrial are analyzed carefully.In the end,the perspectives for future development of battery flame retardant technology are briefly discussed.展开更多
The bituminous defect that the binder is flammable will bring road safety risk.Once it catches fires,large quantities of heat,smoke and poisonous gas are produced,released and spread quickly,which seriously hinder esc...The bituminous defect that the binder is flammable will bring road safety risk.Once it catches fires,large quantities of heat,smoke and poisonous gas are produced,released and spread quickly,which seriously hinder escape and rescue and harms heavily traffic safety.The common flame retardant system is used to modify the asphalt.Cone Calorimeter is adopted to evaluate the burning property of asphalt.The performance of the flame retardant is evaluated by limiting oxygen index and orthogonal design method.The paper analyzes the synergism of the asphalt and flame-retardant,and analyzes the effect of the flame on preventing the smoke to spread and demonstrates that the use of common flame retardants which is added into binder is good at reducing the flammability of the binder.This way can increase the safety of asphalt pavement when fire occurs in the tunnel.The study suggests that flame retardancy of asphalt can be evaluated by Limit Oxygen Index (LOI) and the flame retardancy property of asphalt has marked change according to the content of flame retardant.SB has perfect flame retardancy property,and ATH is better than MH in the effect of flame retardant.展开更多
PI novel caged bicyclic phosphate flame retardant tri(1-oxo-2,6,7-trioxa-1-phosphabicyclo [2.2.2] octane-methyl) phosphate (Trimer) was synthesized from 1-oxo-4-hydroxymethyl-2,6,7-trioxa-1-phosphabicyclo [2.2.2] octa...PI novel caged bicyclic phosphate flame retardant tri(1-oxo-2,6,7-trioxa-1-phosphabicyclo [2.2.2] octane-methyl) phosphate (Trimer) was synthesized from 1-oxo-4-hydroxymethyl-2,6,7-trioxa-1-phosphabicyclo [2.2.2] octane (PEPA) and phosphorus oxychloride in this paper. Its structure was characterized by elemental analysis. FTIR, H-1 NMR. P-31 NMR and X-ray diffraction analysis.展开更多
This study reports the presence of brominated flame retardants in the topsoil in and around Harbin, a city in northeastern China. Samples of soil were collected from 17 locations in 2006, and the levels of 9 polybromi...This study reports the presence of brominated flame retardants in the topsoil in and around Harbin, a city in northeastern China. Samples of soil were collected from 17 locations in 2006, and the levels of 9 polybrominated diphenylethers (PBDEs 17, 28, 47, 66, 99, 100, 153, 154, and 183) ranged from 2.45 to 55.9 pg/g dry weight (dw) with a mean of 26.3 pg/g dw. These levels are very low comparing with those for some cities in Europe and USA. BDE 209 and hexabromocyclododecane were the two dominant congeners, with mean concentrations of 520 pg/g dw and 1750 pg/g dw, respectively. The concentrations of the total nine PBDE congeners clearly decreased from urban areas to background, but the compositions of individual congeners differed. Proportions of heavier congeners decreased while those of lighter congeners increased, along urban-rural-background transect, providing evidence for an urban fractionation effect. Correlation analysis indicated similar sources for PBDEs, hexabromocyclododecane, and 1,2-bis(2,4,6-tribromophenoxy)-ethane from urban areas but pentabromoethylbenzene was probably present due to long-range atmospheric transport. Principal component analysis was used to determine the characteristics of the relationships among these brominated flame retardants in the field.展开更多
The effect of Ti3C2 MXene nanosheets on the intumescent flame retardant(IFR)poly(lactic acid)(PLA)composites was investigated among a series of PLA/IFR/MXene,which were prepared by melt blending 0-2.0 wt%MXene,10.0 wt...The effect of Ti3C2 MXene nanosheets on the intumescent flame retardant(IFR)poly(lactic acid)(PLA)composites was investigated among a series of PLA/IFR/MXene,which were prepared by melt blending 0-2.0 wt%MXene,10.0 wt%-12.0 wt%IFR and PLA together.The results of limiting oxygen index(LOI)and vertical burning(UL-94)discover that the combination of 0.5 wt%MXene and 11.5 wt%IFR synergistically improves the fire safety of PLA to reach UL-94 V-0 rating with LOI value of 33.0%.The PLA/IFR/MXene composites perform an obvious reduction in peak of heat release rate(HRR)in cone calorimeter tests(CCTs).Furthermore,the carbon residues after CCTs were characterized by scanning electron microscope(SEM),laser Raman spectroscopy(LRS),X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS).It is demonstrated that both the titanium composition of the MXene structure and the characteristics of the two-dimensional material enhance the PLA/IFR/MXene composite materials’ability to produce a dense barrier layer to resist burnout during thermal degradation.展开更多
A novel phosphorus-nitrogen containing intumescent flame retardant (P-N IFR) was prepared via the reaction of dichlor-opentate with N-methylaniline. The structure of the product was confirmed by ^1H NMR, ^31p NMR, M...A novel phosphorus-nitrogen containing intumescent flame retardant (P-N IFR) was prepared via the reaction of dichlor-opentate with N-methylaniline. The structure of the product was confirmed by ^1H NMR, ^31p NMR, MS and IR. TGA analysis showed it has effective thermal stability.展开更多
The synergistic effects of silicotungstic acid (SiW12) as a catalyst in the phosphorus-nitrogen compounds AM-based intumescent flame-retardant (IFR) polypropylene (PP) were studied using the limiting oxygen index (LOI...The synergistic effects of silicotungstic acid (SiW12) as a catalyst in the phosphorus-nitrogen compounds AM-based intumescent flame-retardant (IFR) polypropylene (PP) were studied using the limiting oxygen index (LOI), the UL-94 test, thermogravimetric analysis (TGA), real time Fourier transform infrared (FTIR), laser Raman spectroscopy (LRS). The LOI data show that SiW12 added to PP/IFR systems has a synergistic FR effect with an IFR additive named AM. The TGA data show that SiW12 apparently increases the thermal stability of the PP/IFR systems at high temperature (T > 500degreesC). The FTIR results provide the positive evidence that IFR can improve the thermal stability of PP and SiW12 can induce a higher rate of formation of phosphoric acid and its derivatives. The LRS measurements provide useful information on the carbonaceous microstructures. In short, a suitable amount of SiW12 (1.5 wt%) exerts synergistic effects with the IFR by increasing the LOI value and the thermal stability at high temperature and promoting the formation of charred structures on the burning PP surface.展开更多
A flame retardant (DPA-SiN) containing phosphorus, nitrogen and silicon elements was synthesized. The halogen free flame retardant was incorporated into PC/ABS to improve its flame retardancy. The flame-retardant pr...A flame retardant (DPA-SiN) containing phosphorus, nitrogen and silicon elements was synthesized. The halogen free flame retardant was incorporated into PC/ABS to improve its flame retardancy. The flame-retardant properties of the PC/ABS/DPA-SiN blends were estimated by limiting oxygen index (LOI) values and CONE Calorimeter, while thermal stabilities were investi- gated through thermo gvavimetric analysis (TGA). The PC/ABS/DPA-SiN blends were thermally degraded at 400℃ for different amounts of time and studied by Fourier transform infrared spectroscopy (FTIR) to better understand the degradation behavior of PC/ABS/DPA-SiN.展开更多
Polyvinyl alcohol (PVA) has been widely used in the fields of medical, food and packaging due to its excellentbiocompatibility, good fiber-forming and film-forming properties. However, the high flammability of PVA has...Polyvinyl alcohol (PVA) has been widely used in the fields of medical, food and packaging due to its excellentbiocompatibility, good fiber-forming and film-forming properties. However, the high flammability of PVA hasgreatly limited its wider applications. The flame-retardant PVA was prepared by melt blending of a bio-basedflame retardant (prepared from lignin, phosphoric acid and carbamide) with thermoplastic PVA (TPVA). Thechemical structure, morphology, thermal properties, mechanical properties, fire property and fluidity of thisflame retardant PVA were investigated by Fourier transform infrared spectrometer(FTIR), field emission scanning electron microscope(SEM), thermogravimetric analyzer(TGA), impact tester, universal testing machine,horizontal-vertical burning tester, limiting oxygen indexer(LOI) and melt flow rate meter(MFR). The resultsshowed that the prepared flame retardant had good compatibility with the PVA substrate;The impact strength,melt flow rate, fire property and char residue of this PVA material increased with the content of bio-based flameretardant. When the content of flame retardant was of 20%, the five indices including impact strength, meltflow rate, UL-94 level, LOI and char residual were 11.3 KJ/m^(2), 21.2 g/10 min, V-0 UL-94 level, 33.1%, and19.2%, respectively. This research can promote the high-value utilization of lignin and the application ofPVA in the fields of fire protection.展开更多
A series of wear and flame resistant polyamide 6(PA6)composites were prepared using glass fiber(GF)and talc(T)as reinforcer,polytetrafluoroethylene(PTFE)and graphite(Gr)as solid lubricants,red phosphorus(RP)and zinc b...A series of wear and flame resistant polyamide 6(PA6)composites were prepared using glass fiber(GF)and talc(T)as reinforcer,polytetrafluoroethylene(PTFE)and graphite(Gr)as solid lubricants,red phosphorus(RP)and zinc borate(ZB)as flame retardant.The tribological property,mechanical property,flame retardant property and the flame retardant mechanism were investigated.The tests show that the formula of the wear resistant PA6 composite(WRPA 6)is PA6/GF/T/PTFE/Gr in the ratio of 100/15/5/10/5 by mass.Because this composite exhibits the lowest friction coefficient(0.1429)and no wear mass loss,the introduction of RP and ZB can increase the flame resistance of WRPA6,and the synergistic effect of RP and ZB is obtained.Detailedly,the composite with 4 parts of ZB and 12 parts of RP shows the best flame retardant property,achieving the highest limiting oxygen index(LOI)(30.2 vol%)and a UL94 V-0 rating,and the flame retardant mechanisms may be gas phase along with condense phase mechanism.展开更多
Glass fiber reinforced polypropylene(GF-PP)composites have high flammability on account of wick effect which leads to accelerated flow of the polymer melt along the glass fibers(GF)surface to the flame zone.In this st...Glass fiber reinforced polypropylene(GF-PP)composites have high flammability on account of wick effect which leads to accelerated flow of the polymer melt along the glass fibers(GF)surface to the flame zone.In this study,dipentaerythritol(DPER),a charring agent,was adsorbed on the GF surface through the hydrogen bond between silane coupling agent and DPER.DPER has a synergistic effect with the intumescent flame retardants(IFR)added in the composites,which can induce interfacial carbonization on the surface of GF,thus transforming the intrinsic smooth GF surface into roughness one.In this way,the negative effect of the wick effect in flame retardancy is weakened.Moreover,the char residues remained on the surface of GF can bring an improved adhesion between GF and char residues formed in the resin so that a more stable barrier char layer is formed.The PP composites with 20 wt%modified glass fiber(M-GF)and 30 wt%IFR can achieve the UL-94 V-0,and its limiting oxygen index(LOI)value increased from 16.5%to 29.5%.Simultaneously,the heat release rate(HRR),total heat release(THR)and total smoke release(TSR)decreased significantly,and the peak of heat release rate(PHRR)reduced60.6%compared with GF-PP.展开更多
UV curable hyperbranched prepolymers based on amine-ester, ester-amide and ether-amide started with AB_2-type monomers have been prepared by the authors. A series of work on allyl ether maleate hyperbranched polyester...UV curable hyperbranched prepolymers based on amine-ester, ester-amide and ether-amide started with AB_2-type monomers have been prepared by the authors. A series of work on allyl ether maleate hyperbranched polyesters for UV curing coatings by Hult and his colleagues has been reported. However, the UV cured films from those materials are all flammable when attached to fire without addition of flame retardants.展开更多
In this study,tannic acid(TA)was investigated as flame retardant agent for PLA.Different strategies to modify its thermal degradation pathway have been explored in order to improve its charring effect.The first one co...In this study,tannic acid(TA)was investigated as flame retardant agent for PLA.Different strategies to modify its thermal degradation pathway have been explored in order to improve its charring effect.The first one consists in combining TA with organomodified montmorillonite(oMMT),and enables limiting the thermo-oxidative degradation of TA and promoting the formation of an effective char layer.Flame-retardant(FR)behavior of PLA-based composition has been found to be positively impacted by this combination since a reduction of the peak of Heat Release Rate(PHRR),more important than the value recorded when oMMT and tannic acid are used separately,has been obtained.The second strategy,in which tannic acid was associated with a biosourced phosphorousbased compounds,i.e.metallic phytate salt,evidenced another alternative allowing enhancing TA flame retardant effect at 30 wt%loading content.The third and last strategy explored aims to chemically modify TA via a chemical grafting of phosphoric acid groups.This phosphorylated TA was shown to present the most effective flame-retardant(FR)effect.However,an important reduction of PLA molecular weight was observed.展开更多
Quest for bio-based halogen-free green flame retardant has attracted many concerns in recent years.Herein a reactive functional flame retardant containing phosphorus VDP is synthesized from vanillin,9,10-dihydro-9-oxa...Quest for bio-based halogen-free green flame retardant has attracted many concerns in recent years.Herein a reactive functional flame retardant containing phosphorus VDP is synthesized from vanillin,9,10-dihydro-9-oxa-10-phosphophene-10-oxide(DOPO)and phenol via a facile way.VDP is characterized with^(1)H NMR,^(31)P NMR,FTIR and Time of Flight Mass Spectrometry,and used as a new reactive flame retardant for bisphenol epoxy thermosets.Thermogravimetry analysis shows that when the VDP loading is only 0.5P%(based on phosphorus content),the residue increases from 14.2%to 21.1%at 750℃ in N_(2)compare with neat DGEBA.Correspondingly,the limit oxygen index increased to 29.6%,and flame retardancy reaches UL-94 V0 grade.Micro combustion calorimetry(MCC)and cone calorimetry analyses demonstrate that VDP can significantly lower flammability of the epoxy thermoset.With only 0.5P%of VDP,the heat release rate,total heat release rate and smoke production are reduced markedly.At the same time,the mechanical properties of the modified epoxy thermosets are also improved.The impact strength increases by 34%and the flexural strength increased by 23%,with 1.5P%of VDP.In short,VDP not only improves the flame retardancy,but also improves the mechanical properties of the epoxy thermosets.展开更多
基金Funded by the Natural Science Foundation of Guangdong(Nos.2014A030313241,2014B090901068,and 2016A010103003)。
文摘By using 6,6-((sulfonylbis(4,1-phenylene)bis(azanediyl))bis(thiophen-2-ylm-ethylene))bis6H-di-benzo[c,e][1,2]oxaphosphinine 6-oxide(DOPO-N)as phosphorus-nitrogen flame retardant,the polyurea(PUA)with flame retardant properties(PUA/DOPO-N)was prepared.In addition,organically modified montmorillonite(OMMT)and magnesium hydroxide(MH)were used as co-effectors respectively,and the flame retardant PUA(PUA/DOPO-N/OMMT and PUA/DOPO-N/MH)were also prepared.Thermal properties,flame retardant properties,flame retardant mechanism and mechanical properties of PUA/DOPO-N,PUA/DOPO-N/OMMT and PUA/DOPO-N/MH were investigated by thermogravimetric(TG)analysis,limiting oxygen index(LOI),UL 94,cone calorimeter test,scanning electron microscopy(SEM),and tensile test.The results show that the LOI value of PUA/20%DOPO-N,PUA/18%DOPO-N/2%OMMT and PUA/15%DOPO-N/5%MH are 27.1%,27.7%,and 28.3%,respectively,and UL 94 V-0 rating is attained.Compared with PUA,the peak heat release rate(pk-HRR),total heat release(THR)and average effective heat combustion(av-EHC)of PUA/20%DOPO-N,PUA/18%DOPO-N/2%OMMT and PUA/15%DOPO-N/5%MH decrease significantly.SEM results indicate that the residual chars of PUA/20%DOPO-N,PUA/18%DOPO-N/2%OMMT and PUA/15%DOPO-N/5%MH are completer and more compact.The complex of DOPO-N/OMMT and DOPO-N/MH have synergistic flame retardancy.The mechanical properties of PUA can be improved by the addition of DOPO-N,DOPO-N/OMMT and DOPO-N/MH,respectively.The insulation performance test shows that the volume resistivity of PUA/20%DOPO-N is 6.25×10^(16)Ω.cm.Furthermore,by using modified boron nitride(MBN)as heat dissipating material,the complex of PUA/MBN was prepared,and the thermal conductivity of PUA/MBN was investigated.The thermal conductivity of PUA/8%MBN complex coating at room temperature is 0.166 W/(M·K),which is a 163%improvement over pure PUA.
文摘Flame retardant coatings are functional materials that can serve as decorative and protec-tive substrates in the event of a fire.Flame retardant coatings generally consist of two parts:a base material and a flame retardant agent.A detailed introduction was given to the development of flame retardant coatings in recent years and the flame retardants used in flame retardant coatings.Flame retardants mainly include halogen flame retar-dants,phosphorus nitrogen flame retardants,expansion flame retardants,biomass flame retardants,and graphene flame retardants.The application of flame retardant coatings in the fields of epoxy resin,polyurethane,etc.was elaborated.In addition,the application of new biomass flame retardants and graphene flame retardants was introduced,and the future development of flame retardant coatings and flame retardants was described.
基金Supported by the Opening Project of Hubei Three Gorges Laboratory (No.SK213008)the Innovation Fund of Key Laboratory of Green Chemical Process of Ministry of Education (No.GCXP202109)。
文摘Aluminum hypophosphite microspheres(AHP) were synthesized by hydrothermal method using NaH2PO2·H2O and AlCl3·6H2O as raw materials, and then the AHP microspheres were polymerized by surface polymerization of micro-nanospheres with cyclic cross-linked poly(cyclotriphosphazene-co-4,4'-sulfonyldiphenol)(PZS). A new organic-inorganic poly(phosphonitrile)-modified aluminum hypophosphite microspheres(PZS-AHP) were synthesized by encapsulation and applied to flame retardant thermoplastic polyurethane(TPU). The microstructure and chemical composition of the PZS-AHP microsphere were characterized by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy and X-ray spectroscopy. The thermal stability of PZS-AHP microsphere was explored with thermogravimetric analysis. Thermogravimetric data indicate that the PZS-AHP microspheres have excellent thermal stability. The thermal and flame-retarding properties of the TPU composites were evaluated by thermogravimetric(TG), limited oxygen index tests(LOI), and cone calorimeter test(CCT). The TPU composite achieved vertical burning(UL-94) V-0 grade and LOI value reached 29.2% when 10 wt% PZS-AHP was incorporated. Compared with those of pure TPU, the peak heat release rate(pHRR) and total heat release(THR) of TPU/10%PZS-AHP decreased by 82.2% and 42.5%, respectively. The results of CCT indicated that PZS-AHP microsphere could improve the flame retardancy of TPU composites.
基金the National Natural Science Foundation of China (No.51673059)the Science and Technology Planning Project of Henan Province (No. 212102210636)the Opening Project of Jiangxi Province Key Laboratory of Polymer Micro/Nano Manufacturing and Devices (East China University of Technology)。
文摘Polyamide 6 (PA6) was employed as a charring agent of intumescent flame retardant (IFR) to improve the flame retardancy of ethylene-vinyl acetate copolymer (EVA). Different processing procedures were used to regulate the localization of IFR in the EVA matrix. Localizations in which IFR was dispersed in the PA6phase or in the EVA phase were prepared. The effect of the localization of IFR on the flame retardancy of EVA was investigated. The limited oxygen index (LOI), vertical burning (UL 94) and cone calorimeter test (CCT)showed that the localization of IFR in the EVA matrix exhibited a remarkable influence on the flame retardancy.Compared with EVA/IFR, a weak improvement in the flame retardancy was observed in the EVA/PA6/IFR blend withthe localization of IFR in the PA6 phase. When IFR was regulated from the PA6 phase to the EVA matrix,a remarkable increase in the flame retardancy was exhibited. The LOI was increased from 27.8%to 32.7%, and the UL 94 vertical rating was increased from V-2 to V-0. Moreover, an approximately 41.36%decrease in the peak heat release rate was exhibited. A continuous and compact intumescent charring layer that formed in the blends with the localization of IFR in the EVA matrix should be responsible for its excellent flame retardancy.
基金financially supported by the National Natural Science Foundation of China (22178242)。
文摘A flame retardant containing multiple antiflaming elements usually exhibits high-efficient flame retardancy. Here, a novel P/N/Si-containing ammonium polyphosphate derivative(APTES-APP) is synthesized from ammonium polyphosphate(APP) and silane coupling agent(3-aminopropyl)triethoxysilane(APTES)via cation exchange, which is quite different in the chemical structure from APTES-modified APP for retaining silicon hydroxyls. APTES-APP is highly efficient for the epoxy resin. 8%(mass) APTES-APP imparts excellent flame retardancy to the epoxy resin, with a V-0 rating at the UL-94 test(1.6 mm)and an LOI value of 26%(vol). The peak heat release rate and total smoke production of the flameretardant epoxy resin are decreased by 68.1% and 31.3%, respectively. The synergy of P/N/Si contributes to the well-expanded char residue with a strong and dense surface layer, which is a very good barrier against heat and mass transfer. Besides, there is no significant deterioration in the mechanical properties of flame-retardant epoxy resin thanks to silicon hydroxyls forming hydrogen bonds with epoxy molecules. Meanwhile, other molecules can be grafted onto APTES-APP via these silicon hydroxyls, if needed.Briefly, this work has developed a new strategy for amino silane as flame retardants. In conjunction with a low-cost and simple preparation method, APTES-APP has a promising prospect in the high-performance flame-retardant epoxy.
基金supported by the“Jie Bang Gua Shuai”of Science and technology Projects of Liaoning Province in 2021,grant number 2021JH1/10400091Liao Ning Revitalization Talents Program,grant number XLYC2005002+2 种基金Liaoning BaiQianWan Talents Program,grant number[2020]78Scientific Research Funding Project of the Educational Department of Liaoning Province in 2020,grant number LZ2020002Shenyang Science and Technology Program-Major Key Core Technology Project,grant number 20-202-1-15.
文摘As one of the most popular research directions,the application safety of battery technology has attracted more and more attention,researchers in academia and industry are making efforts to develop safer flame retardant battery.The battery consists of electrolyte,separator,electrode and shell,the traditional flame retardant method of battery is to modify the components to improve its flame safety.In this review,varied types of battery flame retardant technology are initially described,including the type of flame-retardants,flame retardant behaviors and flame retardant mechanisms.Latest research progress of various battery flame retardant technologies is summarized.Typical flame retardant approaches and important properties of flame retardant battery are reviewed as well.In addition,the current main challenges of the battery flame retardant technology in both academics and the industrial are analyzed carefully.In the end,the perspectives for future development of battery flame retardant technology are briefly discussed.
基金Sponsored by the National Natural Science Foundation of China (Grant No. 50078057)Program for New Century Excellent Talents in University(Grant No. NCET-06-0340)
文摘The bituminous defect that the binder is flammable will bring road safety risk.Once it catches fires,large quantities of heat,smoke and poisonous gas are produced,released and spread quickly,which seriously hinder escape and rescue and harms heavily traffic safety.The common flame retardant system is used to modify the asphalt.Cone Calorimeter is adopted to evaluate the burning property of asphalt.The performance of the flame retardant is evaluated by limiting oxygen index and orthogonal design method.The paper analyzes the synergism of the asphalt and flame-retardant,and analyzes the effect of the flame on preventing the smoke to spread and demonstrates that the use of common flame retardants which is added into binder is good at reducing the flammability of the binder.This way can increase the safety of asphalt pavement when fire occurs in the tunnel.The study suggests that flame retardancy of asphalt can be evaluated by Limit Oxygen Index (LOI) and the flame retardancy property of asphalt has marked change according to the content of flame retardant.SB has perfect flame retardancy property,and ATH is better than MH in the effect of flame retardant.
文摘PI novel caged bicyclic phosphate flame retardant tri(1-oxo-2,6,7-trioxa-1-phosphabicyclo [2.2.2] octane-methyl) phosphate (Trimer) was synthesized from 1-oxo-4-hydroxymethyl-2,6,7-trioxa-1-phosphabicyclo [2.2.2] octane (PEPA) and phosphorus oxychloride in this paper. Its structure was characterized by elemental analysis. FTIR, H-1 NMR. P-31 NMR and X-ray diffraction analysis.
基金supported by the Heilongjiang Province Postdoctoral Research Funding (No. AUGA41001074)
文摘This study reports the presence of brominated flame retardants in the topsoil in and around Harbin, a city in northeastern China. Samples of soil were collected from 17 locations in 2006, and the levels of 9 polybrominated diphenylethers (PBDEs 17, 28, 47, 66, 99, 100, 153, 154, and 183) ranged from 2.45 to 55.9 pg/g dry weight (dw) with a mean of 26.3 pg/g dw. These levels are very low comparing with those for some cities in Europe and USA. BDE 209 and hexabromocyclododecane were the two dominant congeners, with mean concentrations of 520 pg/g dw and 1750 pg/g dw, respectively. The concentrations of the total nine PBDE congeners clearly decreased from urban areas to background, but the compositions of individual congeners differed. Proportions of heavier congeners decreased while those of lighter congeners increased, along urban-rural-background transect, providing evidence for an urban fractionation effect. Correlation analysis indicated similar sources for PBDEs, hexabromocyclododecane, and 1,2-bis(2,4,6-tribromophenoxy)-ethane from urban areas but pentabromoethylbenzene was probably present due to long-range atmospheric transport. Principal component analysis was used to determine the characteristics of the relationships among these brominated flame retardants in the field.
基金support from the National Natural Science Foundation of China(Grant Nos.21908031 and 51903092)the China Postdoctoral Science Foundation funded project(Grant No.2019M652884)support from Guangdong Special Support Program(Grant No.2017TX04N371)。
文摘The effect of Ti3C2 MXene nanosheets on the intumescent flame retardant(IFR)poly(lactic acid)(PLA)composites was investigated among a series of PLA/IFR/MXene,which were prepared by melt blending 0-2.0 wt%MXene,10.0 wt%-12.0 wt%IFR and PLA together.The results of limiting oxygen index(LOI)and vertical burning(UL-94)discover that the combination of 0.5 wt%MXene and 11.5 wt%IFR synergistically improves the fire safety of PLA to reach UL-94 V-0 rating with LOI value of 33.0%.The PLA/IFR/MXene composites perform an obvious reduction in peak of heat release rate(HRR)in cone calorimeter tests(CCTs).Furthermore,the carbon residues after CCTs were characterized by scanning electron microscope(SEM),laser Raman spectroscopy(LRS),X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS).It is demonstrated that both the titanium composition of the MXene structure and the characteristics of the two-dimensional material enhance the PLA/IFR/MXene composite materials’ability to produce a dense barrier layer to resist burnout during thermal degradation.
文摘A novel phosphorus-nitrogen containing intumescent flame retardant (P-N IFR) was prepared via the reaction of dichlor-opentate with N-methylaniline. The structure of the product was confirmed by ^1H NMR, ^31p NMR, MS and IR. TGA analysis showed it has effective thermal stability.
基金This work was supported by a grant from the Knowledge-Creating Engineering Fund of the Chinese Academy of Science.
文摘The synergistic effects of silicotungstic acid (SiW12) as a catalyst in the phosphorus-nitrogen compounds AM-based intumescent flame-retardant (IFR) polypropylene (PP) were studied using the limiting oxygen index (LOI), the UL-94 test, thermogravimetric analysis (TGA), real time Fourier transform infrared (FTIR), laser Raman spectroscopy (LRS). The LOI data show that SiW12 added to PP/IFR systems has a synergistic FR effect with an IFR additive named AM. The TGA data show that SiW12 apparently increases the thermal stability of the PP/IFR systems at high temperature (T > 500degreesC). The FTIR results provide the positive evidence that IFR can improve the thermal stability of PP and SiW12 can induce a higher rate of formation of phosphoric acid and its derivatives. The LRS measurements provide useful information on the carbonaceous microstructures. In short, a suitable amount of SiW12 (1.5 wt%) exerts synergistic effects with the IFR by increasing the LOI value and the thermal stability at high temperature and promoting the formation of charred structures on the burning PP surface.
基金Funded by Shanghai Science and Technology Commission of China (No.05dz22303)
文摘A flame retardant (DPA-SiN) containing phosphorus, nitrogen and silicon elements was synthesized. The halogen free flame retardant was incorporated into PC/ABS to improve its flame retardancy. The flame-retardant properties of the PC/ABS/DPA-SiN blends were estimated by limiting oxygen index (LOI) values and CONE Calorimeter, while thermal stabilities were investi- gated through thermo gvavimetric analysis (TGA). The PC/ABS/DPA-SiN blends were thermally degraded at 400℃ for different amounts of time and studied by Fourier transform infrared spectroscopy (FTIR) to better understand the degradation behavior of PC/ABS/DPA-SiN.
基金This work was financially supported by the following funds:National Natural Science Foundation of China(51803055)Hunan Provincial Natural Foundation of China(2019JJ50472)+5 种基金Scientific Research Fund of Hunan Provincial Education Department of China(18C0979,19A391)Opening Fund of National&Local Joint Engineering Laboratory for New Petro-chemical Materials and Fine Utilization of Resources(KF201802)Hunan Province Key Field R&D Program Project(2019GK2246)Key Scientific Research Project of Huaihua University(HHUY2019-04)Hunan Provincial Key Research and Development Program(2018GK2062)Science and Technology Plan Project of Huaihua City(2020R3101).
文摘Polyvinyl alcohol (PVA) has been widely used in the fields of medical, food and packaging due to its excellentbiocompatibility, good fiber-forming and film-forming properties. However, the high flammability of PVA hasgreatly limited its wider applications. The flame-retardant PVA was prepared by melt blending of a bio-basedflame retardant (prepared from lignin, phosphoric acid and carbamide) with thermoplastic PVA (TPVA). Thechemical structure, morphology, thermal properties, mechanical properties, fire property and fluidity of thisflame retardant PVA were investigated by Fourier transform infrared spectrometer(FTIR), field emission scanning electron microscope(SEM), thermogravimetric analyzer(TGA), impact tester, universal testing machine,horizontal-vertical burning tester, limiting oxygen indexer(LOI) and melt flow rate meter(MFR). The resultsshowed that the prepared flame retardant had good compatibility with the PVA substrate;The impact strength,melt flow rate, fire property and char residue of this PVA material increased with the content of bio-based flameretardant. When the content of flame retardant was of 20%, the five indices including impact strength, meltflow rate, UL-94 level, LOI and char residual were 11.3 KJ/m^(2), 21.2 g/10 min, V-0 UL-94 level, 33.1%, and19.2%, respectively. This research can promote the high-value utilization of lignin and the application ofPVA in the fields of fire protection.
基金Project(149929)supported by the Postdoctoral Fund of Central South University,ChinaProject(16C0292)supported by the Hunan Education Department,ChinaProject(2016TP1022)supported by the Hunan Provincial Key Lab of Dark Tea and Jin-hua,China
文摘A series of wear and flame resistant polyamide 6(PA6)composites were prepared using glass fiber(GF)and talc(T)as reinforcer,polytetrafluoroethylene(PTFE)and graphite(Gr)as solid lubricants,red phosphorus(RP)and zinc borate(ZB)as flame retardant.The tribological property,mechanical property,flame retardant property and the flame retardant mechanism were investigated.The tests show that the formula of the wear resistant PA6 composite(WRPA 6)is PA6/GF/T/PTFE/Gr in the ratio of 100/15/5/10/5 by mass.Because this composite exhibits the lowest friction coefficient(0.1429)and no wear mass loss,the introduction of RP and ZB can increase the flame resistance of WRPA6,and the synergistic effect of RP and ZB is obtained.Detailedly,the composite with 4 parts of ZB and 12 parts of RP shows the best flame retardant property,achieving the highest limiting oxygen index(LOI)(30.2 vol%)and a UL94 V-0 rating,and the flame retardant mechanisms may be gas phase along with condense phase mechanism.
基金supported by the National Natural Science Foundation of China(21878092,21838003,91834301)the Shanghai Scientific and Technological Innovation Project(18JC1410500,19JC1410400)+1 种基金the Innovation Program of Shanghai Municipal Education Commissionthe Fundamental Research Funds for the Central Universities(222201718002)。
文摘Glass fiber reinforced polypropylene(GF-PP)composites have high flammability on account of wick effect which leads to accelerated flow of the polymer melt along the glass fibers(GF)surface to the flame zone.In this study,dipentaerythritol(DPER),a charring agent,was adsorbed on the GF surface through the hydrogen bond between silane coupling agent and DPER.DPER has a synergistic effect with the intumescent flame retardants(IFR)added in the composites,which can induce interfacial carbonization on the surface of GF,thus transforming the intrinsic smooth GF surface into roughness one.In this way,the negative effect of the wick effect in flame retardancy is weakened.Moreover,the char residues remained on the surface of GF can bring an improved adhesion between GF and char residues formed in the resin so that a more stable barrier char layer is formed.The PP composites with 20 wt%modified glass fiber(M-GF)and 30 wt%IFR can achieve the UL-94 V-0,and its limiting oxygen index(LOI)value increased from 16.5%to 29.5%.Simultaneously,the heat release rate(HRR),total heat release(THR)and total smoke release(TSR)decreased significantly,and the peak of heat release rate(PHRR)reduced60.6%compared with GF-PP.
基金Supported by the National Natural Science Foundation of China(No. 20074034).
文摘UV curable hyperbranched prepolymers based on amine-ester, ester-amide and ether-amide started with AB_2-type monomers have been prepared by the authors. A series of work on allyl ether maleate hyperbranched polyesters for UV curing coatings by Hult and his colleagues has been reported. However, the UV cured films from those materials are all flammable when attached to fire without addition of flame retardants.
文摘In this study,tannic acid(TA)was investigated as flame retardant agent for PLA.Different strategies to modify its thermal degradation pathway have been explored in order to improve its charring effect.The first one consists in combining TA with organomodified montmorillonite(oMMT),and enables limiting the thermo-oxidative degradation of TA and promoting the formation of an effective char layer.Flame-retardant(FR)behavior of PLA-based composition has been found to be positively impacted by this combination since a reduction of the peak of Heat Release Rate(PHRR),more important than the value recorded when oMMT and tannic acid are used separately,has been obtained.The second strategy,in which tannic acid was associated with a biosourced phosphorousbased compounds,i.e.metallic phytate salt,evidenced another alternative allowing enhancing TA flame retardant effect at 30 wt%loading content.The third and last strategy explored aims to chemically modify TA via a chemical grafting of phosphoric acid groups.This phosphorylated TA was shown to present the most effective flame-retardant(FR)effect.However,an important reduction of PLA molecular weight was observed.
基金This work is supported by the National Natural Science Foundation of China(NSFC)under the agreements of 21875131 and 21773150The Natural Science Basic Research Plan in Shaanxi Province of China(2020JM-283)the Fundamental Research Funds for the Central Universities(GK202003044 and GK201902014)are also acknowledged for partial support。
文摘Quest for bio-based halogen-free green flame retardant has attracted many concerns in recent years.Herein a reactive functional flame retardant containing phosphorus VDP is synthesized from vanillin,9,10-dihydro-9-oxa-10-phosphophene-10-oxide(DOPO)and phenol via a facile way.VDP is characterized with^(1)H NMR,^(31)P NMR,FTIR and Time of Flight Mass Spectrometry,and used as a new reactive flame retardant for bisphenol epoxy thermosets.Thermogravimetry analysis shows that when the VDP loading is only 0.5P%(based on phosphorus content),the residue increases from 14.2%to 21.1%at 750℃ in N_(2)compare with neat DGEBA.Correspondingly,the limit oxygen index increased to 29.6%,and flame retardancy reaches UL-94 V0 grade.Micro combustion calorimetry(MCC)and cone calorimetry analyses demonstrate that VDP can significantly lower flammability of the epoxy thermoset.With only 0.5P%of VDP,the heat release rate,total heat release rate and smoke production are reduced markedly.At the same time,the mechanical properties of the modified epoxy thermosets are also improved.The impact strength increases by 34%and the flexural strength increased by 23%,with 1.5P%of VDP.In short,VDP not only improves the flame retardancy,but also improves the mechanical properties of the epoxy thermosets.