An experimental setup for observation of smoldering‐to‐flaming transition on flexible foam/fabric assemblies

Fires that involve upholstered furniture frequently begin as a smoldering combustion and, with time, transition to a flaming combustion, which sharply increases the level of hazard. Therefore, understanding how the compositions of the primary flammable components of the furniture, ie, flexible foam and upholstery fabric, affect this transition is important for fire safety considerations. In the current study, an experiment was designed to observe this transition using a sample consisting of 30 × 15 × 6 cm³ rectangular foam block covered with 30 × 15 cm² piece of fabric. For a representative system of 1.8 lb/ft³ (29 kg/m³) flexible polyurethane foam and 11 oz (0.37 kg/m²) cotton fabric, 0.69 transition probability was measured. This probability decreased by a factor of 4 when a small amount of phosphorus‐based flame retardant, Fyrol® HF‐9, was added to the foam. The transition to flaming was speculated to be associated with the formation of adjacent pyrolysis and smoldering regions within the foam. The pyrolysis region, dominated by anaerobic decomposition, provided gaseous fuel, the ignition of which resulted in the transition. The smoldering region, dominated by oxidation reactions at the solid‐gas interface, generated the heat necessary to maintain the pyrolysis process and ignite the gaseous fuel.     

Flame-resistant polyester/cotton fabrics

New experimental results are reported for the modification of 50/50 polyester/cotton blend fabrics made from bromine-free and bromine-containing polyester with a reactive flame retardant compound of high phosphorus content. Reaction of the cotton in the blend with methyl-phosphonic diamide yields modified fabrics in which flame resistance is attained without impairment of fabric hand. The level of flame resistance depends on the amount of insolubilized phosphorus in the treated fabric, but the hand is essentially unchanged even for fabrics of high phosphorus content which pass the vertical test of DOC-FF-3-71. The results of this work provide a basis for improved definitions of future approaches to the development of flame resistant polyester/cotton blend fabrics.     

Flame retardant finishing of the polyester/cotton blend fabric using a cross‐linkable hydroxy‐functional organophosphorus oligomer

Blend fabrics of cotton and polyester are widely used in apparel, but high flammability becomes a major obstacle for applications of those fabrics in fire protective clothing. The objective of this research was to investigate the flame retardant finishing of a 50/50 polyester/cotton blend fabric. It was discovered previously that N,N′‐dimethyloldihydroxyethyleneurea (DMDHEU) was able to bond a hydroxy‐functional organophosphorus oligomer (HFPO) onto 50/50 nylon/cotton blend fabrics. In this research, the HFPO/DMDHEU system was applied to a 50/50 polyester/cotton twill fabric. The polyester/cotton fabric treated with 36% HFPO and 10% DMDHEU achieved char length of 165 mm after 20 laundering cycles. The laundering durability of the treated fabric was attributed to the formation of polymeric cross‐linked networks. The HFPO/DMDHEU system significantly reduced peak heat release rate (PHRR) of cotton on the treated polyester/cotton blend fabric, but its effects on polyester were marginal. HFPO/DMDHEU reduced PHRR of both nylon and cotton on the treated nylon/cotton fabric. It was also discovered that the nitrogen of DMDHEU was synergistic to enhance the flame retardant performance of HFPO on the polyester/cotton fabric.     

Effect of condensed-phase and gas-phase flame retardants on the ignition behaviour of cotton fabric

The purpose of this study is to evaluate the effect of some well-known flame retardants on the ignition behaviour of cotton fabric. Two types of flame retardants acting in different phases (e.g. condensed phase and gas phase) were used. At low add-on of the retardant acting in the condensed phase the ignition behaviour of the cotton is different from that treated with retardant acting in the gas phase. The condensed-phase retardant caused cotton to burn more rapidly than untreated fabrics. This was attributed to the fact that small add-on of the retardant makes the fuel for the flame available at a lower temperature. However, in the presence of sufficient amounts of retardant, the decomposition of cellulose becomes more directed towards the dehydration mechanism and thus the concentration of the flammable gases is insufficient to reach the flammability limits required. When gas-phase flame retardants were used, a linear dependency of ignition time on the concentration of additive was found. This is explained in terms of the dilution effect of this retardant on the fuel produced from the decomposing fabric.     

GMA改性磷酸腺苷的制备及其对棉织物的阻燃整理

为了提高磷酸腺苷单体在棉织物上的接枝改性程度及其阻燃效果,采用甲基丙烯酸缩水甘油酯（GMA）对一磷酸腺苷（AMP）、二磷酸腺苷（ADP）、三磷酸腺苷（ATP）进行改性,制得三种带有不饱和双键的阻燃单体AMP-m-GMA、ADP-m-GMA、ATP-m-GMA;然后通过紫外光接枝法将三种阻燃单体分别接枝到棉织物上,制备光接枝AMP-m-GMA、ADP-m-GMA和ATP-m-GMA阻燃棉织物;对三种阻燃单体进行了结构表征和热稳定性分析,并探究了三种阻燃单体光接枝阻燃棉织物的热稳定性、阻燃性能、燃烧行为和残炭结构。结果表明,三种磷酸腺苷通过GMA环氧基开环引入不饱和双键,且具有良好的热稳定性。相比于原棉织物,三种阻燃棉织物的最大热降解速率分别降低了60.0%、52.0%、60.0%,极限氧指数由16.1%分别提升到25.4%、27.4%、26.4%,织物热释放速率分别下降了15.09%、60.47%、37.82%,说明三种磷酸腺苷阻燃单体均有助于棉织物形成致密炭层,阻止热量扩散,获得良好的阻燃效果。其中,光接枝ADP-m-GMA阻燃棉织物的增重率可达22.4%,燃烧后损毁长度由30 cm缩短至14.2 cm,表现出更优异的阻燃性能。     

Ignition and combustion of low‐density polyimide foam

The ignition, flaming and smoldering combustion of low‐density polyimide foam have been studied using a cone calorimeter. Low‐density polyimide foam exhibits a high ignition resistance. The minimum heat flux for the ignition of flaming combustion ranges from 48 to 54 kW/m². This minimum heat flux also indicates the heat flux for transition from smoldering to flaming combustion. The flaming combustion results show that the heat release rate of low‐density polyimide foam is very low even at a high incident heat flux of 75 kW/m². The smoldering combustion results show that the smoldering of low‐density polyimide foam becomes significant when the incident heat flux is greater than 30 kW/m². The smoldering combustion of low‐density polyimide foam cannot be self‐sustaining when the external heat source is removed. Copyright © 2003 John Wiley & Sons, Ltd.     

The piloted transition to flaming in smoldering fire retarded and non‐fire retarded polyurethane foam

The piloted transition from smoldering to flaming, though a significant fire safety concern, has not been previously extensively studied. Experimental results are presented on the piloted transition from smoldering to flaming in non‐fire retarded (NFR) polyurethane foam and the fire retarded polyurethane foam Pyrell^®. The samples are small blocks, vertically placed in the wall of an upward wind tunnel. The free surface is exposed to an oxidizer flow and a radiant heat flux. The smolder product gases pass upwards through a pilot. The experiments on NFR foam show that the smolder velocity and peak smolder temperature, which increase with the oxygen concentration and heat flux, are strongly correlated to the transition to flaming event, in that there are minimum values of these parameters for transition to occur. The existence of a minimum smolder velocity for ignition supports the concept of a gaseous mixture reaching a lean flammability limit as the criterion for the transition to flaming. To compensate for the solid‐ and gas‐phase effects of the fire retardants on the piloted transition in Pyrell, it was necessary to increase the oxygen concentration and the power supplied to the smolder igniter and the pilot. The piloted transition is observed in oxygen concentrations above 17% in NFR foam and above 23% in Pyrell. The results show that although Pyrell is less flammable than NFR foam, it is still susceptible to smoldering and the piloted transition to flaming in oxygen‐enriched environments, which is of interest for special applications such as future space missions. Copyright © 2008 John Wiley & Sons, Ltd.     

双层涤纶汽车座套面料的阻燃性能研究

选用不同比例的阻燃涤纶和普通涤纶长丝,设计织造了8种双层小提花织物,同时对织物进行了阻燃性能测试。结果表明:1#织物为最优织物,其采用接结双层组织,表里层为质量比1∶1的阻燃涤纶和普通涤纶,织物中使用的阻燃涤纶比例高,阻燃涤纶覆盖率系数大,织物的烫穿时间长,阻燃效果好。与纯阻燃涤纶织物相比,1#织物不仅达到了相同的阻燃效果,还减少了阻燃涤纶的使用量,节约了成本。设计织造的8种织物的阻燃性能均达到汽车用纺织品的阻燃要求,可以供企业在大生产中应用。     

A facile one‐step synthesis of flame‐retardant coatings on cotton fabric via ultrasound irradiation

This article reports a facile one‐step methodology to increase fire resistance properties of cotton fabric. The flame‐retardant coating for cotton fabric was synthesized with methyltriethoxysilane and organophosphates (M102B) through an ultrasound irradiation process. The coating structure and surface morphology of uncoated and coated fabrics were investigated by Fourier transform infrared spectroscopy and scanning electron microscope, respectively. The flame‐retardant properties, bending modulus, air permeability and thermal stability were studied by vertical burning test, cantilever method, air permeability test and thermogravimetric analysis (TGA). As a result, the cotton fabric coated with 29.2% (mass increased) of flame‐retardant coating was able to balance the flame retardant property and wearing comfort of the fabrics. The TGA results showed that the residue char of cotton was greatly enhanced after treatment with the coating, which has a high char forming effect on cellulose during testing. Furthermore, flame‐retardant property of coated fabrics did not change significantly after 10 washing cycles. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45114.     

Polyimide-coated fabrics with multifunctional properties: Flame retardant,UV protective,and water proof

Multifunctional technical textiles are of great interest both by industry and academia and these products are considered as high value-added products that contribute to the economies of countries. In this study, polyamic acid (PAA) was synthesized through polycondensation of pyromellitic dianhydride (PMDA) and 4,4′-oxydianiline (ODA) in dimethyl acetamide (DMAc) at low temperature. Then, PAA was coated onto woven cotton and polyester fabric by padding technique. Finally, polyimide (PI)-coated multifunctional cotton and polyester fabrics were obtained by an easy coating technique and low-temperature imidization. Thus, low cost, easily accessible and widely used cotton and polyester fabrics were converted to high-performance textile products, which are flame retardant, UV protective, acid resistant, and waterproof. The chemical, thermal, morphological, optical, mechanical, wettability, chemical resistance, and flame retardancy properties of developed fabrics were investigated. Optical results showed that both PI-coated cotton and polyester fabrics are UV-A protective compared to noncoated fabrics. Moreover, PI-coated samples have high contact angles which are 111.43° and 113.40° for PI-coated cotton (PI-c-C) and PI-coated polyester (PI-c-PET), respectively. Young's modulus of PI-c-PET fabrics increased four times more than noncoated polyester fabric. PI coating changed the burning behavior of both cotton and polyester fabrics in a positive way. All the test results showed that these developed multifunctional textile products might find an application in different industrial areas such as automotive, aerospace, protective clothing, and so on due to easy and inexpensive production techniques and also superior properties. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47616.     

涤纶汽车座椅面料阻燃工艺的优化

分析了阻燃剂FR-510质量浓度、烘焙温度、烘焙时间对涤纶织物阻燃性能的影响,确定了最优工艺条件:阻燃剂质量浓度100 g/L、焙烘温度150℃、焙烘时间3 min。在此工艺条件下对涤纶织物进行整理,并进行耐水洗和耐摩擦性能测试,研究结果表明:当阻燃涤纶含量为50%时,交织物的阻燃性能最优,耐水洗和耐摩擦性能也满足使用要求,适合用于汽车座椅面料。     

Thermal properties and combustion behavior of POSS‐ and bohemite‐finished cotton fabrics

A finishing process with polyhedral oligomeric silsesquioxane (POSS) and bohemite nanoparticles has been exploited for enhancing the thermal stability and flame retardancy of cotton fabrics. The thermal behavior of flame retardant treated cellulosic fabric has been studied by thermogravimetric analyses (TGAs). It has been found that such nanoparticles favor the carbonization of the cellulose and slow down the kinetics of thermo‐oxidation in air. At the same time, the finished fabrics have turned out to be more efficient with respect to neat cotton as far as the flame retardancy is concerned, pointing out an increase of the time to ignition (TTI) and a decrease of the heat release rate (HRR). Furthermore, a comparison between the fire performances of the nanoparticles under study and a commercial phosphorus‐based flame retardant has been investigated. The morphology and elemental composition present in the treated fabrics have been also investigated using scanning electron microscopy (SEM) coupled to the energy dispersive spectroscopy (EDS), and the results have been compared with the untreated fabric. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

石墨烯微胶囊/海藻酸钙对涤纶织物的阻燃处理

为提高涤纶织物的阻燃性能,并解决涤纶织物的熔滴现象,本文采用石墨烯微胶囊与海藻酸钠共混制备出阻燃涂覆液,采用浸轧法制备阻燃涂覆涤纶织物。考察涂覆涤纶织物的阻燃性能,力学性能以及热学性能,结果表明：25g/L的海藻酸钠和1g的石墨烯微胶囊阻燃涂覆处理后的涤纶织物的极限氧指数由19.7%,上升到28.34%,达到难燃织物的标准。整理后的涤纶织物达到了V-0标准,涤纶织物燃烧后产生的熔滴的现象消失。织物的断裂强力由135.21N降低到了106.77N。涂覆处理前后,织物达到最大热分解速率的温度未产生明显变化,残炭率由12.07%上升到了26.98%,最大质量损失速率由1.79%/℃降低到了0.96%/℃。同时整理前后涤纶织物的热焓值由58.4J/g上升至68.4J/g。织物的导热系数由0.587 W/cm.℃×10_-4^提高到0.842W/cm.℃×10_-4^{,热学性能得到了充分的提高。}织物燃烧后所形成的残炭由无到连续且致密。     

汽车阻燃座套面料的设计与研究

使用阻燃涤纶和普通涤纶纱混织,设计出3种双面组织结构和5种混用比例的针织阻燃面料。采用单因素分析法分析了织物组织结构和混用比例对阻燃性能的影响,并采用Borda法评判了面料的阻燃性、耐磨性、舒适性等指标,最终分析得出满足汽车内饰要求的是组织结构为罗纹空气层,阻燃涤纶与普通涤纶比例为2∶1的针织阻燃面料。     

（急）磷-氮阻燃剂的合成及整理棉织物性能

以亚磷酸二甲酯、丙烯酰胺和三聚氯氰为原料，合成了无甲醛磷-氮阻燃剂，并通过轧焙烘工艺对棉织物进行了阻燃整理。通过红外光谱对中间体和阻燃剂的结构进行了表征。通过红外光谱、电镜和EDS对整理织物的结构、表面形态和元素组成进行了表征，采用极限氧指数、垂直燃烧、锥形量热测试了整理织物的阻燃性能，采用热重测试了整理织物的热稳定性能。结果表明：阻燃剂成功整理到织物上，整理织物的最大热分解速率降低，残炭率提高。整理织物的极限氧指数由18%提高到31%，续燃时间，阴燃时间由9 s，25s均降到0 s，损毁长度由300 mm降低到74 mm。整理织物的最大热释放速率（PHRR）由203.5 kW?m-2降低到57.9 kW?m-2，总释放热（THR）由6.0 MJ?m-2,降低到2.7 MJ?m-2。     

Correlation between limiting oxygen index and phosphorus/nitrogen content of cotton fabrics treated with a hydroxy‐functional organophosphorus flame‐retarding agent and dimethyloldihydroxyethyleneurea

The combination of a hydroxyl‐functional organophosphorus flame‐retarding agent (FR) and dimethyloldihydroxyethyleneurea (DMDHEU) was used as a durable flame‐retardant finish system for cotton fabrics. DMDHEU functions as a binder between FR and cotton cellulose, thus making this flame‐retarding system durable to home laundering. DMDHEU also provides nitrogen to this system, therefore enhances its performance. Limiting oxygen index (LOI) is one of the most commonly used parameters to indicate the flammability of textiles and other polymeric materials. In this research, we investigated the correlation between LOI and phosphorus/nitrogen content on the cotton fabric treated with that durable flame‐retardant system. Phosphorus concentration on the fabric was analyzed by inductively coupled plasma atomic emission spectroscopy, whereas the nitrogen content was determined indirectly by measuring the carbonyl band intensity in the infrared spectra of the treated fabric. We developed a statistical model to predict LOI of the cotton fabric treated with FR and DMDHEU based on the phosphorus concentration and the intensity of carbonyl band of DMDHEU on cotton. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1885–1890, 2003     

Preparation and performance evaluation of phosphorus-nitrogen synergism flame-retardant water-borne coatings for cotton and polyester fabrics

Three phosphorus-nitrogen content effective synergist flame-retardant water-borne coatings have been synthesized, and their structures were characterized by infrared spectroscopy. Cotton and polyester fabrics have been treated by coatings to improve their flame retardancy. The thermal performances and flame retardant properties of treated samples were investigated by thermogravimetric analysis (TGA), horizontal flame test, vertical burning test, limiting oxygen index (LOI), scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS), respectively. The combustion performances of cotton and polyester fabrics have proven to be strongly affected by flame-retardant coatings and HFD-coating performed the best. As a result, the LOI value of treated cotton increased to 22.5, and the UL-94 value of treated polyester achieved V-0. In addition, the antistatic behavior, hydrostatic pressure, tearing strength and wrinkle recovery angle of samples were studied carefully, and the results showed that all of these performances were improved.     

苯酐聚酯多元醇聚氨酯硬泡的阻燃性研究

以国产苯酐聚酯多元醇为主要原料制备了组合聚醚,再与多异氰酸酯反应,制备了阻燃型聚氨酯硬质泡沫。讨论了苯酐聚酯多元醇、硅油及发泡剂等因素对泡沫阻燃性的影响。结果表明,该组合聚醚与多异氰酸酯反应,制得的阻燃型聚氨酯硬质泡沫,其氧指数在28以上,压缩强度为300kPa,达到了国家标准GB／T8624-1997中B2级氧指数的要求。     

Developments in flame-retarding polyester/cotton blends

The burning behaviour of polyester/cotton blended fabrics is discussed and possible flame-retardant strategies outlined. Particular attention is paid to the effectiveness of phosphorous- and nitrogen-containing and antimony(III) oxide/halogen flame-retardant systems. Recent developments within the UK are discussed which suggest that phosphonium salt condensate finishes are effective on cotton-rich blends and that antimony-halogen systems may be used on all polyester/cotton blend compositions. Both types of flame retardant have acceptable durability to laundering.     

硅-磷阻燃剂对涤纶织物的阻燃研究

采用极限氧指数法（LOI）、垂直燃烧法等手段研究甲基三甲氧基硅烷包覆聚磷酸铵的协同阻燃剂,与水性聚氨酯组成阻燃涂层剂,对涤纶织物的阻燃效果。结果表明：甲基三甲氧基硅烷和聚磷酸铵配比为2：1,阻燃剂与水性聚氨酯配比为1：2,阻燃剂质量浓度为160g／L,烘焙温度为180℃,烘焙时间为120s,阻燃涤纶织物的极限氧指数为44．3％,损毁长度为29mm,阴燃时间和续燃时间均为0,达到GB20286-2006标准中的阻燃1级。