Flame Retardancy, Smoke Suppression Effect and Mechanism of Aryl Phosphates in Combination with Magnesium Hydroxide in Polyamide 6

The flammability, smoke emission behavior and mechanical properties of two oligomeric aryl phosphates [bisphenol A bis（diphenyl phosphate） （BDP） and resorcinol bis（diphenyl phosphate） （RDP）] combined with magnesium hydroxide （MH） in polyamide 6 （PA6） have been investigated. Combining 5 wt% BDP, 50 wt% MH imparts a limiting oxygen index （LOI） of 40.9% and UL94 V-0 rating to PA6, meanwhile the peak rate of smoke release （pRSR）, total release of smoke （TSR） and Izod notched impact strength are 41%, 33% and 233% relative to the corresponding value of 55 wt% MH without BDP, respectively. Dynamic mechanical analysis （DMA） indicates that the improvement of toughness attributes to the enhanced compatibility between MH and PA6 by adding BDP. Furthermore, based on the comprehensive analysis of thermogravimetry （TG）, cone calorimeter and SEM-EDX investigations, possible flame retardancy and smoke suppression mechanisms were revealed. Besides the fuel dilution and barrier effect of MH, the combination of MH and RDP shows an additional flame inhibition effect. The combination of MH and BDP results in a dominant condensed phase barrier effect which leads to obvious reduction on smoke emission and flammability.

An Effective Green Porous Structural Adhesive for Thermal Insulating,Flame-Retardant,and Smoke-Suppressant Expandable Polystyrene Foam

To develop an efficient way to overcome the contradiction among flame retardancy,smoke suppression,and thermal insulation in expanded polystyrene(EPS)foams,which are widely used insulation materials in buildings,a novel"green"porous bio-based flame-retard ant starch(FRS)coating was designed from starch modified with phytic acid(PA)that simultaneously acts as both a flame retardant and an adhesive.This porous FRS coating has open pores,which,in combination with the closed cells formed by EPS beads,create a hierarchically porous structure in FRS-EPS that results in superior thermal insulation with a lower thermal conductivity of 27.0 mW·(m·K)^(-1).The resultant FRS-EPS foam showed extremely low heat-release rates and smoke-production release,indicating excellent fire retardancy and smoke suppression.The specific optical density was as low as 121,which was 80.6%lower than that of neat EPS,at 624.The FRS-EPS also exhibited self-extinguishing behavior in vertical burning tests and had a high limiting oxygen index(LOI)value of 35.5%.More interestingly,after being burnt with an alcohol lamp for 30 min,the top side temperature of the FRS-EPS remained at only 140℃with ignition,thereby exhibiting excellent fire resistance.Mechanism analysis confirmed the intumescent action of FRS,which forms a compact phosphorus-rich hybrid barrier,and the phosphorus-containing compounds that formed in the gas phase contributed to the excellent flame retardancy and smoke suppression of FRS-EPS.This novel porous biomass-based FRS system provides a promising strategy for fabricating polymer foams with excellent flame retardancy,smoke suppression,and thermal insulation.

Study on the Built-up Effect of Inorganic Compounds to Flame Retardant Containing Organophosphorus in Suppression of Smoke

The built-up effect of inorganic compounds containing more active metal ions, such as Ca^2＋ , Al^3＋ , Cu^2＋ , and Zn^2＋ , as additives adding to phosphorus-containing flame retarding systems in suppression of smoke was studied. The data presented herein suggested that the amount of smoke in the burning process can be better suppressed after the cotton fabric finishing with built-up system was burnt. Some general principles were identified, and the likely causes of the observed effects were analyzed according to test data.

Durable flame-retardant,smoke-suppressant,and thermal-insulating biomass polyurethane foam enabled by a green bio-based system

Bio-based polyurethane foam has attracted increasing attentions due to eco-friendliness and fossil feedstock issues.However,the inherent flammability limits its application in different fields.Herein,we demonstrate a green bio-based flame-retardant system to fabricate polyurethane foam composite with durable flame retardancy,smoke suppression,and thermal insulation property.In this system,the green bio-based polyol(VED)with good reactivity and compatibility plays a role of flame retardant and EG acts as a synergistic filler.As a result,the LOI value of foam composite increased to 30.5 vol.%and it achieved a V-0 rating in the UL-94 vertical burning test.Additionally,the peak heat release rate(pHRR)and the total smoke production(TSP)decreased by 66.1%and 63.4%,respectively.Furthermore,the foam composite maintained durable flame retardancy after accelerated thermal aging test,whose thermal-insulating property was maintained even after being treated in high-humidity environment with 85%R.H.for a week.This work provides a facile strategy for durable flame retardancy and long-term thermal insulation performance,and creates opportunities for the practical applications of bio-based foam composites.

Influence of Beta-Cyclodextrin Functionalized Tin Phenylphosphonate on the Thermal Stability and Flame Retardancy of Epoxy Composites

To enhance the thermal stability and flame retardancy of epoxy resin(EP),beta-cyclodextrin(β-CD)is successfully introduced into the layered tin phenylphosphonate(SnPP),which is incorporated into EP matrix for preparing EP/β-CD@SnPP composites.The results indicate that the addition ofβ-CD@SnPP obviously improve the thermal stability and residual yield of EP composites at higher temperature.When the amount ofβ-CD@SnPP is only 4 wt%,EP/4β-CD@SnPP composites pass V-1 rating,and LOI value is up to 30.8%.Meanwhile,β-CD@SnPP effectively suppress the heat release and reduce the smoke production of EP/β-CD@SnPP composites in combustion,and the peak heat release rate(PHRR),total heat release(THR),smoke production rate(SPR)of EP/6β-CD@SnPP composites reduce by 28.4%,33.0%and 44.8%by comparison with those of pure EP.The good flame retardancy and smoke suppression are ascribed to the synergistic effect of excellent carbon-forming capability and fire retardancy ofβ-CD@SnPP.

Facile Synthesis of a Novel Bio-Based P-N Containing Flame Retardant for Effectively Reducing the Fire Hazards of Epoxy Resin

In this work,a bio-based flame retardant(Cy-HEDP)was synthesized from cytosine and HEDP through a facile salt-forming reaction and embedded into epoxy matrix to improve the flame retardancy and smoke suppression performance.The product Cy-HEDP was well characterized by FTIR,^(1)H and^(31)P NMR and SEM tests.On the basis of the results,by adding 15 wt%Cy-HEDP,the EP15 can pass UL-94 V-0 rating,and the total smoke production(TSP)as well as total heat release(THR)can be decreased by 61.05%(from 22.61 to 8.7 m^(2)/m^(2))and 39.44%(from 103.19 to 62.50 MJ/m^(2))in comparison to the unfilled EP,reflecting the attenuated smoke toxicity and impeded heat generation.According to the analysis results of residual char,it can be concluded that Cy-HEDP possessed the ability to promote the formation of continuous and dense char layers,which would be a physical barrier to insulate oxygen and prevent heat feedback during the combustion of EP.This work provide inspiration towards developing bio-based flame retardant,probably extending the prospects to other polymeric material system.

Study on Flame-retardation and Smoke-suppression Characteristics and Mechanism of NSCFR Flame Retardant or Wood

NSCFR flame retardant is one of key factors of non-smoke combustible wood-based materials.Thermal analysis,cone calorimetry,Py-GC/MS, scanning electron microscopy(SEM) were utilized to investigate the flame-retardation and smoke-suppression characteristics and mechanisms of NSCFR flame-retardant.The results show that NSCFR flame-retardant could significantly shorten the combustion duration of wood-based materials and completely eliminate the second peak of heat release rate curve,greatly reduce heat release rate, total smoke release,mass loss rate,specific extinction area,and carbon monoxide production and carbon dioxide production,obviously enhance the mass of combustion char residue,effectively retarding the combustion and inhibiting smoke release of the wood-based material;NSCFR flame-retardant exhibits the ability of flame retardancy on wood by the conjunct mechanism of capturing free radical, diluting combustible gas,and catalyzing charring; NSCFR flame-retardant displays smoke suppression effects on wood by absorption action of nano alveolate structure together with the active catalyzing action of ironic molybdate.

APP/ZB协效阻燃发泡木塑复合材料性能研究

为了拓宽发泡木塑复合材料(FWPC)的功能性,以沙柳木粉、高密度聚乙烯(PE-HD)为主要原料,纳米炭黑(Nano-CB)为导电填料,聚磷酸铵(APP)和硼酸锌(ZB)作为阻燃剂和抑烟成分进行复配,采用发泡工艺和模压法制备阻燃抗静电型发泡木塑复合材料。研究APP/ZB协效阻燃剂质量比对FWPC力学性能、阻燃抑烟性能及热稳定性能的影响。结果表明:当APP/ZB总加入量为20%,质量比为4∶1时,FWPC的各项性能相对较优,静曲强度、弹性模量、拉伸强度和冲击强度分别为30.11MPa、2636MPa、14.65MPa和3.72kJ/m^(2),氧指数达27.3%,属难燃级别;与单独加APP时相比,力学性能降低,烟释放速总量降低11.93%,CO产率峰值和平均CO产率分别降低80.6%和49.3%,总失重率从63.53%降至61.42%,热稳定性能提高;FWPC燃烧后炭层表面凹凸不平,复合材料的阻燃和抑烟性能得到提升。

焦磷酸哌嗪@COF阻燃剂的制备及其对环氧树脂的阻燃作用

通过溶液合成法制备了一种共价有机框架(COF),再将COF包覆在焦磷酸哌嗪(PAPP)上形成PAPP@COF杂化阻燃剂,并将其应用于EP中。通过氧指数测定仪、垂直燃烧测定仪和锥形量热仪分析了PAPP@COF杂化阻燃剂对EP的阻燃及消烟性能的影响。结果表明,加入2%(质量分数,下同)的PAPP@COF时,EP复合材料的氧指数达到了30.0%,热释放速率峰值为911.35 k W/m^(2),烟释放速率峰值为0.394 m^(2)/s,相比于纯EP分别降低了37.36%和34.27%。PAPP@COF杂化阻燃剂对EP有优异的阻燃和消烟作用,为COF类阻燃剂的研究提供了一定的基础。

可膨胀石墨/硅橡胶泡沫材料制备及其阻燃性能研究

硅橡胶材料兼具有机材料柔韧性和无机材料的热稳定性,已经在各个领域取得了显著的增长。通过低温法制备了具有优异阻燃性能、较好力学性能、低成本、泡孔结构丰富的可膨胀石墨(EG)/硅橡胶泡沫复合材料,其可有效提高硅橡胶泡沫的阻燃性能。结果表明:添加10%EG可以提高硅橡胶泡沫的拉伸强度、断裂伸长率和硬度等力学性能指标,同时硅橡胶泡沫的密度增加,回弹性有所降低。锥型量热仪(CCT)测试表明,EG的添加有助于延迟点火时间(TTI),降低热释放速率(HRR)和总热释放量(THR)等参数,且有助于提高抑烟性能。适量添加EG可以改善硅橡胶泡沫的热稳定性,过量会导致产生“飞灰”现象。这些特征结合在一起预示着EG/硅橡胶泡沫复合材料由于出色的阻燃性质可在阻燃材料领域得到广泛的应用。

Mo-MOF对软质PVC材料的阻燃及抑烟性能

采用熔融共混的方法将含钼离子的有机框架材料(Mo-MOF)添加到软质聚氯乙烯(PVC)材料中,利用极限氧指数(LOI)测试仪、NBS烟箱、锥形量热仪、拉伸强度测试仪等研究了材料的阻燃、抑烟及力学性能。测试结果表明,与软质PVC相比,当Mo-MOF的添加量为3%时,材料的LOI值由26.8%提高至30.3%,最大烟密度由918.5降低至471.2,总烟释放量(TSP)由25.23 m^(2)降低至12.02 m^(2),分别降低了48.7%及52.3%。此外,与PVC/MoO_(3)对比可知,当钼离子含量相同时,PVC/3%Mo-MOF材料的最大烟密度由774.0降低至471.2,TSP值由17.55 m^(2)降低至12.02 m^(2),分别降低了39.1%与31.5%。与MoO_(3)相比,Mo-MOF在PVC中的相容性及分散性更佳,在燃烧过程中形成了具有高比表面积的纳米级氧化钼,对PVC材料的阻燃及抑烟性能更佳。同时,随着Mo-MOF含量的增加,PVC材料的拉伸强度和断裂伸长率均得到了一定程度的提高。

二硫化钼 还原氧化石墨烯对涤纶织物的阻燃性能

为了赋予涤纶(PET)织物良好的阻燃、抑烟性能,实现PET织物的低烟、无卤阻燃,采用浸轧工艺,用水热法制备二硫化钼还原氧化石墨烯(MoS_(2)/RGO)复合材料,并将其用于PET织物的阻燃整理。采用扫描电子显微镜、红外光谱仪以及X射线衍射仪等对MoS_(2)/RGO复合材料以及MoS_(2)/RGO/PET织物的微观形貌与化学结构进行分析;采用垂直燃烧测试仪、烟雾密度箱、接触角仪等对MoS_(2)/RGO/PET织物的阻燃、抑烟性能以及亲水性能进行表征与测试。结果表明:MoS_(2)/RGO复合材料在织物上能够形成良好包覆,且能够有效提高PET织物的热稳定性,在700℃时,其残炭率较纯织物明显提升;MoS_(2)/RGO/PET织物的极限氧指数可提升至28.2%,总热释放量较纯PET织物下降60.5%,烟雾密度降低59.9%,具有良好的自熄性能,损毁长度可降低至10.6 cm。此外,MoS_(2)/RGO复合材料可以赋予PET织物良好的亲水性能,在2.2 s时接触角变为0°,有效改善了PET织物的服用舒适性能。

抑烟阻燃微胶囊开发与性能验证

沥青路面施工过程烟气污染严重,且服役过程存在火灾风险隐患,严重危害了行车安全。因此,抑烟阻燃型沥青路面材料研发势在必行。传统的抑烟阻燃路面是将抑烟剂与阻燃剂分别添加到沥青混合料中,其过程繁多,且过量的抑烟剂与阻燃剂会导致沥青路面路用性能下降,不利于路面的长期服役。而采用微胶囊技术则可以兼顾抑烟与阻燃性能。其中,微胶囊外壳采用具有良好抑烟性能的膨胀石墨与活性炭,芯材采用具有阻燃性能优异的氢氧化镁与蒙脱土。由此重点对沥青烟气的抑制效果进行了研究,并发现当微胶囊掺量为3%时,对烟气中的CO、VOCs抑制效果最佳,抑制率可达49%和40%。由于微胶囊拥有抑烟外壳,在抑制烟气的同时,还可以有效防止芯材泄漏,从而保护了沥青路面的路用性能,降低了多种抑制剂对沥青路面的损害。

海泡石膨胀阻燃体系对三元乙丙橡胶阻燃抑烟性能的影响

采用硅烷偶联剂(KH550)对海泡石进行改性,制得改性海泡石(K-SEP),并将聚磷酸铵膨胀型阻燃体系(AEG)与焦磷酸哌嗪膨胀型阻燃体系(PEG)复配,制备了两种生物基阻燃抑烟体系AEGS和PEGS,研究了AEGS和PEGS对三元乙丙橡胶基复合材料的阻燃抑烟性能。结果表明,添加3份K-SEP的复合材料EPDM/AEGS3和EPDM/PEGS3氧指数分别比不加海泡石的空白样品高8.01%和5.61%,总烟雾释放量分别降低了42.39%和10.31%,表明了海泡石在聚合物材料阻燃抑烟领域可发挥较大的作用。

海泡石在氯化聚乙烯阻燃复合材料中的应用

以氯化聚乙烯(CPE)为基体材料、海泡石为阻燃剂制备了CPE阻燃复合材料,研究了海泡石用量对其硫化特性、物理机械性能和阻燃性能的影响。结果表明,随着海泡石加入量的增加,复合材料的拉伸强度、撕裂强度、100%定伸应力、300%定伸应力和邵尔A硬度均显著提高;海泡石的加入提高了CPE阻燃复合材料的极限氧指数,降低了复合材料燃烧时的最大热释放速率和热总释放量,延长了复合材料的点燃时间,降低了一氧化碳和二氧化碳的绝对含量,减少了烟雾的排放。

玻璃纤维/环氧树脂复合材料燃烧特性研究

采用锥形量热仪、垂直水平燃烧试验仪、极限氧指数测试仪等手段研究玻璃纤维/环氧树脂复合材料在不同火灾环境下的燃烧特性。结果表明:随热辐射强度的增加,实验样品的平均点燃时间逐渐缩短,热释放速率和热释放速率峰值均增大,峰值出现时间提前,燃烧后残余率降低。由于玻璃纤维的抑制作用,复合材料总体质量损失幅度较小。实验样品在水平燃烧试验中未能点燃,在垂直燃烧试验中,平均烧焦长度48.3mm,移去火源后的平均焰燃时间为11.8s。氧指数试验显示,温度升高200℃后,其值降为室温氧指数的74.9%,表明在高温环境下复合材料更易被点燃。玻璃纤维的存在能够抑制环氧树脂的热解和燃烧。

A biobased flame retardant towards improvement of flame retardancy and mechanical property of ethylene vinyl acetate

A new biobased flame retardant(MHPA)with remarkable compatibility was synthesized via a facile and low-cost neutralization reaction of magnesium hydroxide(MH)and phytic acid(PA).By blending the prepared MHPA into ethylene vinyl acetate(EVA),the fire retardancy,smoke suppression and mechanical properties of the composites were significantly improved.When 50 wt%of MH was added into EVA matrix,the value of limiting oxygen index(LOI)reached 26.1%.Whereas,when 10 wt%MH in the EVA composites(with initial 50 wt%MH)was replaced by MHPA,the resulted EVA composites had a LOI value of 30.8%,indicating high efficiency of addition of MHPA to improve flame retardancy.Moreover,the heat release rate(HRR)and total smoke production(TSP)of the EVA composites reduced by 54.4%and 27.6%,respectively,suggesting that incorporation of MHPA could effectively hinder rapid degradation of EVA composites during burning process.The fire-retardant mechanism may reside in that the MHPA combined with MH can present the excellent carbonization and expansion effects.This study illustrates that the biobased MHPA has a broad application prospect to develop flame-retardant EVA composites.

壳聚糖-磺化石墨烯层层自组装涂层对硬质聚氨酯泡沫的阻燃抑烟性能研究

采用以水为溶液的层层自组装法(LBL)在硬质聚氨酯泡沫(RPUF)表面构筑了不同层数的壳聚糖-磺化石墨烯的生物基阻燃涂层,探索了不同层数(x BL)对RPUF阻燃、抑烟性能的影响。结果表明,覆有防火涂层的RPUF表现出优异的阻燃性、热稳定性和抑烟能力,且其性能随着涂覆层数增加而增强;与未处理的样品相比,经过5层自组装涂覆的RPUF-5BL可通过UL 94 V-0级,极限氧指数(LOI,35.1%)和800℃残炭量(34.9%,质量分数,下同)分别提高了78.2%和85.6%;热释放速率峰值(pHRR,163.9 kW/m^(2))、总产烟量(TSP,9.1 m^(2))、最大烟密度(MSD,22.9%)和烟密度等级(SDR,14.9)分别下降了30.6%、14.2%、61.9%和120.1%。

焦磷酸哌嗪/三聚氰胺聚磷酸盐协效阻燃ABS应用研究

以焦磷酸哌嗪(PAPP)/三聚氰胺磷酸盐(MPP)为阻燃剂,并以锡酸锌(ZS)、三氧化二锑(AT)、次磷酸铝(AHP)为协效抑烟剂。采用熔融共混法制备无卤阻燃丙烯腈-丁二烯-苯乙烯共聚物(ABS)复合材料。复合材料的性能通过热重分析仪、氧指数测试仪、垂直燃烧试验机、烟密度仪和扫描电子显微镜等仪器测试。结果表明:添加30份PAPP/MPP复合阻燃剂时,ABS复合材料的极限氧指数得到大幅提升,同时添加AT、ZS、AHP时,ABS复合材料的极限氧指数进一步提高,抑烟性能也得到改善,其中ZS效果最好。拉伸性和弯曲强度在ABS复合材料上基本保持稳定,但缺口冲击强度明显减小。添加复合阻燃剂,在提高炭层密实度的同时,减缓ABS复合材料的热分解速度,增强其热稳定性,最终提高了ABS复合材料的阻燃性能。

高分子材料阻燃抑烟中的自由基捕捉作用

烟毒气体导致的窒息性死亡是火灾中最主要的致死原因,如何降低高分子材料燃烧过程中的烟毒气体释放,对于火灾中人员逃生和救援至关重要。燃烧过程中自由基链式反应向气相释放出来的高活性H·和HO·是引起高分子材料氧化降解的根本原因,有效控制高活性自由基向气相的释放是改善高分子材料阻燃抑烟性能的有效途径。综述了高分子材料阻燃抑烟中的自由基捕捉作用,从气相自由基捕捉和凝聚相自由基捕捉两个角度简要阐述了多种阻燃剂/协效剂在阻燃抑烟方面的不同表现,重点总结了凝聚相自由基捕捉作用与覆盖阻隔、催化成炭和多孔吸附作用相结合对延缓和抑制烟毒气体释放的影响,并分析了高分子材料阻燃抑烟领域中自由基捕捉作用研究亟待解决的问题。