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     

Flame-retardant viscose–polyester fabrics

For many purposes the natural-synthetic fiber-blend fabrics are more suitable than pure natural or synthetic products. It is often possible to obtain a maximum in clothing and textile technical properties by compensating the defects of one fiber by using an other totally different fiber. Many problems, however, have arisen in the production of flame-retardent fabrics because the use of synthetic fibers often makes the fire retardancy less effective. In our 2-year research project different fire-retardant (FR) viscose–polyesters fabrics were prapared at first in the laboratory scale. The natural type raw materials were Modal Prima viscose and normal FR–viscose cotton type staple fibers. The synthetic raw materials were FR–polyesters of the same type with two different flame retardants. Test fabrics were knitted in the laboratory by using seven blended yarns in the ratios 100/0, 80/20, 65/35, and 50/50 and vice versa. Cotton type PVC–fiber was also used in some experiments. All these test fabrics were also finished chemically by using normal crease-resistant (DMU, DMEU, DMDHEU, and TMM) and flameretardant (N,-methylolphosphonopropionamide and THPC) finishing chemicals. The textile and fire-retardant properties of the original and finished fabrics were estimated by using addon, tensile strength, LOI-value, and vertical flame test determinations. The mechanism of flame retardancy was also studied with DSC technique, P- and N-analysis and char investigations. The test results of viscose/polyester studies were compared with the results of cotton/polyester studies. After laboratory studies the best methods for FR–viscose/polyester fabric production were chosen, and the fabrics were manufactured. The fabrics were home-washed 20–50 times, and the textile and FR-properties were determined after each 10 washings. These results were again compared with results of cotton/polyester fabrics.     

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。     

Fabrication and properties of PEI/APP layer-by-layer coated ramie fabric combined with low-temperature plasma treatment

The present work demonstrates a surface pretreatment of reducing assembly layers for flame retardant modification of ramie fabric used by layer-by-layer (LbL) assembly. In order to achieve this goal, low-temperature plasma (LTP) pretreatment was chosen. Attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and scanning electron microscope (SEM) were used to confirm the effect of LTP pretreatment on polyethylenimine/ammonium polyphosphate (PEI/APP) flame retardant coating constructed on the surface of ramie fabric using LbL assembly. The thermal property and flame retardancy of PEI/APP coated ramie fabrics were analyzed by TG, LOI, UL94 vertical burning, and cone calorimeter tests. The results indicated that the decomposition rate of ramie fabrics was reduced and the char forming ability at high temperature was improved by PEI/APP coating on the ramie surface. Its LOI increased markedly to 30.6% and ramie fabric achieved self-extinguishing effect. Meanwhile, LTP-O₂-(PEI/APP)₂₀ ramie fabric exhibited the low flammability and high fire safety. It was proved that LTP pretreatment under oxygen atmosphere could endow ramie fabric with better flame retardancy due to more PEI/APP adsorbed on its surface. These findings have significant implications for the application of LTP pretreatment to flame retardant modification of ramie fabric by LbL assembly.     

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     

Preparation of a halogen-free P/N/Si flame retardant monomer with reactive siloxy groups and its application in cotton fabrics

A novel halogen-free phosphorus-nitrogen-silicon flame retardant monomer with reactive siloxy groups,N-(diphenylphosphino)-1,1-diphenyl-N-(3-(triethoxysilyl)propyl) phosphinamine (DPTA) has been synthesized and was applied to the fire-resistant finishing of cotton fabrics.The molecular structure of DPTA has been well characterized by elemental analysis,FTIR,1H NMR,and 31p NMR spectroscopies.The chemically-grafted cotton fabrics,which were treated with 25 wt％ DPTA,were obtained and confirmed by attenuated total reflectance Fourier infrared spectroscopy (ATR-FTIR).The flame retardancy and thermal property of the treated samples were investigated by limited oxygen index (LOI),vertical flammability test (VFT),thermogravimetric analysis (TGA) and microscale combustion calorimeter (MCC).It is noted that in vertical flammability test,the treated samples extinguished immediately upon removing the ignition source,whereas the untreated one was completely burned out.Furthermore,TGA and MCC tests revealed that the treated samples produced a high char formation and a low heated release during combustion.The surface morphology of the untreated and treated samples and the char residues after LOI tests were observed by scanning electron microscopy (SEM).Therefore,all the results showed that the treated cotton fabrics with 25 wt％ DPTA apparently improved the fireresistant and thermal performances.     

Flame retardancy in fabric consisting of cellulosic fiber and modacrylic fiber containing fine‐grained MoO3 particles

Flame retardancy of fabrics consisting of modacrylic fiber containing with various dispersed metal compounds and cellulosic fiber has been investigated by means of flame test (ISO15025 procedure A) and limiting oxygen index (LOI). It has been found that excellent flame retardancy is achieved by fine‐grained MoO₃ particles. The afterflame time in flame test and the LOI value are improved with decreasing particle size of MoO₃. The flame retardancy of MoO₃ (particle size; 0.1 µm) is comparable to that of Sb₂O₃. On the other hand, significant improvement in flame retardancy is not observed for other metal compounds although some metal oxides and a hydroxide in the present study are known as flame retardant or smoke suppressing agent in halogen containing polymer in previous studies. In order to clarify the mechanism of the observed flame retardancy by the addition of fine‐grained MoO₃, we have carried out X‐ray fluorescence spectrometry (XRF) measurement of the fabric specimen after the flame test and thermogravimetric analysis (TGA) of various types of samples. These analytical data indicated that MoO₃ works as halogen synergist in solid phase and the char of modacrylic fiber formed by addition of MoO₃ suppresses decomposition of the cotton blended in the fabric in the range of the ignition temperature. Copyright © 2015 John Wiley & Sons, Ltd.     

氧化铋对环状膦酸酯阻燃棉织物的协效阻燃抑烟作用

通过阻燃性能测试、热重分析、锥形量热分析等研究手段,考察了氧化铋对环状膦酸酯阻燃棉织物的阻燃抑烟协效作用。结果发现,在阻燃整理剂中添加0.4 g/L的氧化铋,可以使阻燃棉布的极限氧指数从43%提高到52%;损毁炭长缩短到5 cm,垂直燃烧达到B1级;而对断裂强度影响不大。热重分析表明,氧化铋的加入进一步降低了阻燃棉织物的初始分解温度和最大热解速率,500℃时的成炭量有所增加;扫描电镜显示,添加氧化铋后,棉织物燃烧成炭更致密;氧化铋具有明显的抗燃烧变形能力;锥形量热测试表明,氧化铋的添加不仅降低了阻燃棉织物的总热释放速率,而且使阻燃棉织物的总烟释放量降低了60%。     

A novel halogen‐free and formaldehyde‐free flame retardant for cotton fabrics

A novel halogen‐free and formaldehyde‐free flame retardant (FR), which contains phosphorus, nitrogen, and silicon, was synthesized for cotton fabrics considering the synergistic effect of phosphorus, nitrogen, and silicon. The structure of the new FR was characterized by Fourier‐trans‐form infrared spectroscopy, and the surface morphology of the treated fibre was observed using scanning electron microscope. The thermal property of the FR treated cotton fabric was studied through thermal gravimetric analysis. The TG results indicate that the FR can protect cotton fabric from fire to a certain degree. The vertical flammability test and limiting oxygen index results further indicate that the FR has excellent FR properties. Finally, the durability and other performance properties of the treated fabric were studied and the results show that the new materials can be used as a semi‐durable FR for cellulosic fibres. Copyright © 2011 John Wiley & Sons, Ltd.     

Flame‐retardant fabric systems based on electrospun polyamide/boric acid nanocomposite fibers

To examine the feasibility of developing flame‐retardant‐textile coated fabric systems with electrospun polyamide/boric acid nanocomposites, fiber webs coated on cotton substrates were developed to impart‐fire retardant properties. The morphology of the polyamide/boric acid nanocomposite fibers was examined with scanning electron microscopy. The flame‐retardant properties of coated fabric systems with different nanoparticle contents were assessed. The flame retardancy of the boric acid coated fabric systems was evaluated quantitatively with a flammability test apparatus fabricated on the basis of Consumer Product Safety Commission 16 Code of Federal Regulations part 1610 standard and also by thermogravimetric analysis. The 0.05 wt % boric acid nanocomposite fiber web coated on pure cotton fabric exhibited an increment in flame‐spreading time of greater than 80%, and this indicated excellent fire protection. Also, the coated fabric systems with 0.05% boric acid nanocomposite fiber webs exhibited a distinct shift in the peak value in the thermal degradation profile and a 75% increase in char formation in the thermooxidative degradation profile, as indicated by the results of thermogravimetric analysis. The results show the feasibility of successfully imparting flame‐retardant properties to cotton fabrics through the electrospinning of the polymer material with boric acid nanoparticles. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Effect of a nanoclay/triphenyl phosphate hybrid system on the fire retardancy of polycarbonate/acrylonitrile–butadiene–styrene blend

The effect of a hybrid system of nanoclay and triphenyl phosphate (TPP) on the fire retardancy of a polycarbonate (PC)/acrylonitrile–butadiene–styrene (ABS) blend was examined in this study. The nanoclay in the polymers decreased the peak heat release rates (PHRRs) with no significant effect on the ease of ignition and times to extinguishment. Improvements in the flame retardancy were observed only when nanoparticles were used with conventional flame‐retardant (FR) additives. Thermogravimetric analysis (TGA), cone calorimetry, and limited oxygen index (LOI)/UL 94 (Underwriters Laboratory) testing were used to investigate the thermal degradation, fire behavior, and flammability of the materials. The results show that when we used a combination of TPP and nanoclay as an FR system, degradation of the polymer blends was reduced as the TGA curves shifted to higher temperatures. PHRR in cone calorimetry testing decreased from 1032 kW/m² for the PC/ABS blend to 300 kW/m² for the PC/ABS/(12% TPP–2% nanoclay) sample, and the LOI increased from 23 to 35%, respectively. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Synthesis of carborane acrylate and flame retardant modification on silk fabric via graft copolymerization with phosphate‐containing acrylate

A novel carborane acrylate monomer (1‐acryloyloxyethyl carborane) was synthesized by addition reaction, hydrolysis, and esterification and characterized by proton nuclear magnetic resonance (¹H NMR) spectroscopy and Fourier transform infrared spectroscopy (FT‐IR) analysis. Subsequently, the carborane monomer and a phosphate‐containing methacrylate monomer were applied on the modification of a silk fabric. The heat resistance and flame retardancy of the silk fabric before and after modification were compared. Energy‐dispersive X‐ray spectrometer (EDS) and FT‐IR showed that carborane monomer and phosphate‐containing methacrylate were grafted onto the surface of the fibers. The cross‐sectional morphology of silk fabrics after burning was observed by scanning electron microscope (SEM), and the flame‐retardant mechanism was analyzed. Thermal‐gravimetric analysis (TGA) and differential scanning calorimetry (DSC) analysis revealed that the thermal stability of the modified silk increased with the increase of the grafting yield. The MCC‐2 microcalorimeter (MCC) test showed that, when using 1‐acryloyloxyethyl carborane as monomer and blending with phosphate‐containing methacrylate, the maximum heat release rate (PHRR) of the modified silk fabric decreased from 97.6 W/g (before grafting) to 51.3 and 45.8 W/g, respectively, and the total heat release (THR) decreased from 10.2 kJ/g (before grafting) to 5.9 and 5.2 kJ/g, respectively. The limiting oxygen index (LOI) test revealed that using 1‐acryloyloxyethyl carborane and phosphate‐containing methacrylate as mixed monomers to modify the silk fabric obtained good flame retardancy, whose LOI value reached 29.8%.     

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.     

阻燃PP纺粘无纺布的性能研究

研究了阻燃母粒法和整理法制得的阻燃PP纺粘无纺布的力学性能、热性能和阻燃性能。结果表明:阻燃母粒法制得的阻燃PP纺粘无纺布的断裂强力与PP纺粘无纺布的接近,但断裂伸长率要低,后整理法制得的纺粘无纺布的力学性能与PP纺粘无纺布的接近;两种方法制得的阻燃PP纺粘无纺布的热性能均优于PP纺粘无纺布,在1000℃左右时,有24.0%～33.2%的炭残渣,成炭性较好;两种方法制得的阻燃PP纺粘无纺布的阻燃性能良好,其中用阻燃剂B整理后的PP纺粘无纺布其阻燃效果优于阻燃剂A整理的PP纺粘无纺布。     

Influence of moisture on the flame retardance of textile fabrics

For cotton fabric not treated with a flame retardant (FR), the oxygen index (OI) increases slowly but at a constant rate with moisture content (MC). Above a MC of roughly 33% which roughly equals the water fiber saturation point of the cotton fiber, the increase becomes more rapid but the relation appears to remain linear. The relation between OI and MC is also linear for all the FR cotton fabrics examined up to an OI of at least 40. It is suggested that the moisture in the FR samples is not reducing flammability by entering into solid and/or gaseous phase reactions but by absorbing thermal energy owing to the endothermic process of heating and vaporization. Empirical relations appear to be present between the inherent hydrophilicity of the FR cotton fabrics and the OI of the dry fabric (OI)_o and the temperature of the zenith of the first exothermic peak for the FR cotton fabrics as determined by differential thermal analysis. OI–MC relations for wool fabric and wool treated with an FR are similar to those found for the cotton fabrics except that the slopes of the lines found for the wool samples are lower than those of the equivalent cotton samples. The relation reported by Van Krevelen between OI and char residue for polymeric materials is tested for both the cotton and wool samples. Agreement with Van Krevelen's relation is not good when (OI)_o values are used. Better agreement can be obtained if OIs are determined on samples with MCs between 2 and 10%.     

Flame retardancy finish with an organophosphorus retardant on silk fabrics

The paper mainly deals with flame retardancy of silk fabrics treated with a commercial organophosphorus flame retardant [N‐hydroxymethyl (3‐dimethyl phosphono) propionamide (HDPP), also known as Pyrovatex CP], using the pad‐dry‐cure‐wash method. The structures and properties of the treated and control sample are discussed. The Limiting Oxygen Index (LOI) value of the modified sample is above 30%. After 50 laundry cycles, it still has some flame retardancy left. HDPP and a cross‐linking agent (HMM) were bound to silk fabrics which is confirmed by FT‐IR spectra and amino analysis. The reaction degree of the flame retardant with silk is also high; almost all the tyrosine units have reacted, which can be confirmed by amino acid analysis. The reaction between flame retardant and silk only occurs in the amorphous region of silk fibre, which is confirmed by X‐ray diffraction analysis and amino acid analysis. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) analysis show that the flame retardant causes silk fabrics to decompose below its ignition temperature (600°C) and formed carbonaceous residue or char when exposed to fire. The char behaves as a thermal barrier to fire, so silk fabrics show good flame retardancy. The treatment has a little effect on the whiteness of the silk fabrics and the tensile strength of treated silk fabrics slightly decreased; both effects are negligible. Copyright © 2006 John Wiley & Sons, Ltd.     

Microintumescent mechanism of flame‐retardant water‐based chitosan–ammonium polyphosphate multilayer nanocoating on cotton fabric

Layer‐by‐layer (LbL) assembly of nanocoatings on fabric substrates has been very successful in terms of reduction of flammability. In particular, an LbL system comprised ammonium polyphosphate as the polyanion and chitosan as the polycation, applied to cotton fabric, dramatically reduced cotton flammability. At this point, the fire‐retardant (FR) mechanism of action of this system has never been fully elucidated. Sonicated and nonsonicated coated cotton fabrics were evaluated using a vertical flame test and mass loss calorimeter. Coating morphology was investigated before and after burning. Thermal analyses and chemical analyses in the condensed phase (and in the gas phase) were conducted to reveal the FR mechanism of action. At the cotton surface, a combination of both condensed (formation of aromatic char) and gas phase (release of water and highly flammable gases) mechanisms impart the FR behavior, promoting a kind of “microintumescence” phenomenon. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43783.     

新型磷系阻燃剂阻燃环氧树脂的应用研究

以新戊二醇、三氯氧磷、1,2,3-三羟基苯为原料合成新型磷系阻燃剂1,2,3－三(5,5－二甲基－1,3－二氧杂己内磷酰氧基)苯(FR),将FR与环氧树脂(EP)熔融混合制备阻燃EP/FR复合材料。采用极限氧指数测试、垂直燃烧实验、热重分析、锥形量热分析、扫描电镜研究了FR对EP的阻燃性能和阻燃机理。结果表明,添加20 % FR的EP/FR复合材料的极限氧指数达到27.8 %,垂直燃烧通过UL94 V-0级,热释放速率平均值和生烟量平均值比未阻燃EP分别降低了77.0 %和82.8 %,扫描电镜分析表明, EP/FR体系燃烧后能形成连续、致密、封闭的焦化炭层。     

多层阻燃织物整体热防护性能初探

研究了消防服用多层阻燃织物复合系统的整体热防护性及外层织物的阻燃性。将阻燃织物国产间位芳纶、杜邦NomexⅢ和芳纶3A面料与国产间位芳纶毡和阻燃棉布组合,模拟构成消防服的多层织物结构,通过垂直燃烧实验测试分析了阻燃外层织物的阻燃性能,通过热辐射和热对流综合热防护性能(TPP)实验测试分析了多层复合织物的整体热防护性能。实验结果表明:整体热防护性能最好的是国产间位芳纶织物、面密度200 g/m2的芳纶毡和阻燃棉布的组合,但最适宜用于消防服的是NomexⅢ织物、面密度200 g/m2的芳纶毡和阻燃棉布。     

Flame retardant treated flax fibre reinforced phenolic composites: Ageing and thermal characteristics

In this study, flax composites were prepared from flax fabric and phenolic resin. Chemical treatments were imparted to the fabric to improve adhesion between the fabric and the phenolic matrix. Diammonium phosphate was applied to improve the flammability of the composites. The thermal and flammability properties of the untreated, chemically treated, and flame retardant (FR) treated flax fabric reinforced phenolic composites were studied. Ageing studies were carried out by subjecting the composites to varying conditions of temperature and humidity in an environmental chamber for 2 weeks. FR treatment of flax fabric was shown to be very effective in improving flame retardancy of the composites due to decreased peak heat release rate (PHRR) and smoke production rate (SPR). Thermogravimetric analysis (TGA) of composites showed that after FR treatment, the decomposition temperatures shifted to lower temperatures. Ageing studies revealed that the mechanical properties of untreated, chemically treated and FR treated composites decreased with an increase in ageing temperature.