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1.
A Controlled-atomosphere cone calorimeter was used to investigate the burning of pure and flame retardant-treated cotton fabrics. The condensed-phase flame retardants used were Morguard (containing ammonium dihydrogen phosphate and diammonium hydrogen phoisphate) and Nochar (containing ammonium sulfate and a sodium salt). The fabrics were tested at 25 kW m?2 incident heat flux in environments containing 15–30% oxygen. The flame retardants increased the time to ignition, residue yield, and CO and CO2 yields. The flame retardants decreased the peak and average mass loss rates, the peak and average heat release rates, the effective heat of combustion at peak heat release rate, and the propensity to flashover. The effect of oxygen concentration on the burning of pure and flame retardant-treated cotton fabrics has also been investigated. The flame retardants had better performance when the treated fabrics burned in the lower oxyge concentrations. The result of this study indicate that the controlled-atmosphere cone calorimeter is a good tool for studying the effect of flame retardant and oxygen concentration on the burning of materials. 相似文献
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The combustion of polypropylene flame-retarded by the synergistic action between Sb2O3 and bromine-containing flame retardants has been studied. From the relationship between a number of the variables, a parameter quantatively reflecting the flame retardant effect has been found. With the addition of flame retardant, the rate of weight loss, the CO and CO2 emission rates and heat release all decrease while smoke density increases. These effects were considered to depend on the concentration of HBr gas in the pyrolysates released into the gas phase (i.e., dWHBr/dW, HBr flux ensity), and the following equations were obtained: η*(dW/dt)max, which approximately corresponds to the oxidation velocity of pyrolized hydrocarbon, is inversely proportional to the HBr flux density. As the conversion of CO to CO2 was almost independent of the amount of flame retardants added, the flame retardant effect of bromine-containing flame retardants was considered to be a retardant effect of the initial oxidation reaction at the gas liquid interface. Moreover, η* is almost proportional to the combustion efficiency η, which was obtained from the heat release measured in the flaming region. The heat release is therefore considered to be governed by the HBr flux density. 相似文献
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采用马弗炉、氧指数仪和电子拉力试验机等设备研究了陶瓷化阻燃剂对硅橡胶性能的影响。 相似文献
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研究了不同填充量的反应型和添加型含磷阻燃剂对阻燃环氧树脂力学性能和阻燃性能的影响,并对比研究了2种类型阻燃环氧树脂的热稳定性。结果表明,反应型阻燃剂中9,10-二氢-9-氧-10-磷杂菲-10-氧化物(DOPO)阻燃环氧树脂的力学性能和阻燃性能好于6-氢-二苯并[c,e][1,2]氧磷酰杂-6-甲醇,6-氧化物(DOPO-CH2OH),添加型阻燃剂中三聚氰胺磷酸盐(MP)阻燃环氧树脂的性能好于聚磷酸铵(APP);2种类型阻燃剂相比,2种反应型阻燃剂阻燃环氧树脂的力学性能、阻燃性能和热稳定性均好于添加型的MP和APP阻燃剂。 相似文献
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The melt flow behaviour of polypropylene filled with organoantimony compounds, triphenylstibinedibromide and its derivatives with tribromo-, trichloro-, and pentachloro-phenols, as flame retardants has been studied in the temperature range of 180 to 220°C, and at shear rates of 29.5 to 588.8's?1, using a capillary rheometer. A decrease in the melt viscosity at all shear rates and temperatures was noticed on addition of these flame retardants, The melt viscosity further decreased upon increasing the concentration (from 5 to 20 phr) of the flame retardants. The die swell was measured in order to determine the melt elasticity of the filled systems. The minimum melt viscosity of filled propylene was observed approximately where the maximum die swell (melt elasticity) occurred. 相似文献
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Influence of thermal behavior of phosphorus compounds on their flame retardant effect in PU rigid foam
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Phosphorus‐containing compounds have been widely used as flame retardants for polyurethane rigid foam (PURF). In this work, a number of phosphorus compounds were utilized and studied as flame retardants for PURF, including ammonium polyphosphate, pentaerythritol phosphate, triethyl phosphate, and dimethyl methyl phosphonate. The thermal behavior of flame retardants was thoroughly investigated, such as degradation, vaporization, and the properties of degraded products. The influence of thermal behavior of phosphorus flame retardants on PURF was examined and analyzed. The results indicated that the effect of flame retardant was highly related to their thermal behavior. Phosphorus compounds for gas phase flame retardants were very effective in decreasing the heat release rate and increase limited oxygen index of PURF, while condensed phase flame retardants showed better comprehensive flame retardant effect, such as reducing the toxicity of combustion product. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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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. 相似文献
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Weihua Wang Guoqun Zhao Xianghong Wu Xiuhong Li Chenggong Wang 《Polymer Composites》2015,36(9):1653-1663
In this study, standard test specimens with flame‐retarded short glass fiber‐reinforced PC/ABS materials were fabricated under rapid thermal cycle injection molding condition by selecting a potassium perfluorobutane sulfonate flame retardant specially used for PC, FR2025, and two kinds of aryl phosphorus halogen‐free flame retardants, UN707 and PX‐220. The flame‐retardancy effect of the above different flame retardants on the studied systems was compared through combustion tests of the specimens. Meanwhile, the thermal and mechanical properties of flame‐retarded composites were studied by using the thermogravimetry analysis, dynamic mechanical thermal analysis (DMTA), and universal testing machine. The results show that the “candlewick effect” of fibers exacerbates the fire behavior of composites. With the increase of the aryl phosphorus halogen‐free flame retardants, the flame‐retardancy effect of composites is obviously improved, and the maximum thermal degradation rate of composites is significantly decreased. The UL94 combustion rating is improved, and the time of residual flame is substantially reduced with the increase of PC content under the same content of flame retardant. The DMTA results show that the flame retardants have a reinforcement action on PC/ABS matrix. However, the macroscopic mechanical properties are slightly decreased in the glass fiber‐reinforced composites because of the destructive effect of the flame retardants on the interface compatibility between matrix and fibers; the scanning electron microscopic micrographs of tensile fracture fully prove this action mechanism of flame retardants. In addition, the addition of toughener and antidripping additive significantly affects the flame retardancy and mechanical properties of composites. POLYM. COMPOS., 36:1653–1663, 2015. © 2014 Society of Plastics Engineers 相似文献
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The improved flame retardancy of asphalt binders containing various kinds of flame retardants including antimony trioxide, decabromodiphenyl ether (EBPED), aluminium trihydroxide (ATH) and zinc borate (ZB) under different additive concentrations was investigated by limited oxygen index (LOI) and differential scanning calorimetry (DSC) test. To assess the effects of the type and concentration of the flame retardants on rheological properties of asphalt binders, the softening point, penetration, ductility, storage stability and viscosity were tested. The thin film oven test (TFOT) was used to investigate the effect of short-term oxidation on flame-resistant asphalt binders. Experimental results indicated that all of selected flame retardants had a relatively small effect of rheological properties of the asphalt binders, but a great effect on flame retardancy. Asphalt binder with LOI of 25.9 was obtained by adding 6 wt% mixed flame retardants of EBPED: antimony trioxide: ZB=3:1:1 by mass. Asphalt binder was transformed from inflammable materials into flame retardant materials. Therefore, the asphalt binder with both good flame retardancy and rheological properties is a novel road functional material to meet two respects' demands as flame retardant materials and road materials at the same time. 相似文献
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Greater cure time (crosslinking) and greater elastomer content increases the shrinkability as well as flame retardancy of the blends. Additive flame retardants hamper the heat shrinkability of the blend to some extent depending on various factors. The depression of shrinkability due to interference of flame retarding agent is less for cured sample and elastomer‐rich blend compared to uncured and plastic‐rich blend, respectively. At high temperature the shrinkability is higher, but the sacrifice of shrinkability in the presence of flame retardants increases with increase in temperature, for a particular blend. The highest flame retardancy is obtained in presence of Sb2O3/Chlorohor and TPP/Zn metaborate. 相似文献
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A. G. Shmakov V. M. Shvartsberg O. P. Korobeinichev M. W. Beach T. I. Hu T. A. Morgan 《Combustion, Explosion, and Shock Waves》2007,43(5):501-508
The chemical and thermal structure of a Mache-Hebra burner stabilized premixed rich CH4/O2/N2 flame with additives of vapors of triphenylphosphine oxide [(C6H5)3PO], hexabromocyclododecane (C12H18Br6), and ethyl bromide (C2H5Br) was studied experimentally using molecular beam mass spectrometry (MBMS) and a microthermocouple method. The concentration
profiles of stable and active species, including atoms and free radicals, and flame temperature pro.les were determined at
a pressure of 1 atm. A comparison of the experimental and modeling results on the flame structure shows that MBMS is a suitable
method for studying the structure of flames stabilized on a Mache-Hebra burner under near-adiabatic conditions. The relative
flame inhibition effectiveness of the added compounds is estimated from changes in the peak concentrations of H and OH radicals
in the flame and from changes in the flame propagation velocity. The results of the investigation suggest that place of action
of the examined flame retardants is the gas phase.
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Translated from Fizika Goreniya i Vzryva, Vol. 43, No. 5, pp. 12–20, September–October, 2007. 相似文献
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《Polymer Composites》2017,38(7):1483-1491
Two phosphorous containing reactive flame retardants namely Triallyl phosphate (TAP) and diethylene glycol modified tetra‐allyl phosphate (DTAP) are synthesized and incorporated successfully in commercial Unsaturated polyester (UPR) in various amounts (5, 10, and 15 phr) to yield flame retardant unsaturated polyester (FRUPR) composites. The structures of reactive flame retardant monomers are confirmed by FTIR, 1H‐NMR, and31P‐NMR spectroscopy. Further, FRUPR composites are characterized for their mechanical, thermal, and flame retardant properties. It is observed that tensile strength and hardness of composites are enhanced with the addition of flame retardants; however, flexural strength and impact resistance are lowered. Differential Scanning Calorimetry (DSC) study reveals that there is a significant increase in glass transition temperature with the addition of flame retardants suggesting the formation of dense and crosslinked structure in FRUPR composites. Thermal stability and the flame retardant properties are also observed to be improved with the increase in concentration of flame retardant in UPR as evidenced from Thermo‐gravimetric analysis (TGA). Beyond 10 phr concentration of flame retardants, all composites show V‐0 rating on UL‐94 test. Also, increase in phosphorous content in composites leads to gradual improvement in limiting oxygen index values. POLYM. COMPOS., 38:1483–1491, 2017. © 2015 Society of Plastics Engineers 相似文献
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The diffusion of additives and the deterioration with the passage of time in polypropylene (PP) were studied by using the UL flaming test and the oxygen index test to measure the flame retardancy. The weight change was also measured. The decreases with the lapse of time were observed for multiple flame retardants. Aliphatic brominated compounds showed the best result for flame retardancy in the initial stage of combustion. The best flame retardants for PP to inhibit the deterioration of flame retardancy with the passage of time were brominated hydrocarbon with more than two aromatic rings connected by a functional group or isocyanurate, and phosphates connected with a branching aliphatic hydrocarbon. The weight of the loss was plotted as a function of aging time and temperature to elucidate why the flame retardancy deteriorated. The apparent diffusion constant depends on the temperature and the rate was expressed with the Arrhenius equation. The concentration of flame retardant in PP was calculated by the constant and the equation at arbitrary time after thermal aging. The relation between the performance and chemical structure of the additives was also discussed. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006 相似文献
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Vinyl-type monomers containing bromine and/or phosphorus were synthesized and used as flame retardants for ethylene–propylene–diene terpolymer. The monomers were mixed with the base polymer, Sb2O3 as a synergist, radical initiator, and other additives, and polymerized in the matrix of the base polymer. The monomers act as an effective flame retardants when they form thermally stable polymers comparable to the base polymer. The efficiency was dependent on the amount of flame-retardant polymer formed in the finished compound. 相似文献
20.
Zhi-Gang Yuan Zhao-Hui Shu Liang Qi Wan-An Cai Wen-Bin Liu Jun Wang Mehdi Derradji Yan-hui Wang 《应用聚合物科学杂志》2023,140(1):e53267
In this study, 4,4′-Diaminodiphenyl methane (DDM) was exploited as hardener for diglycidyl ether of daidzein (DGED) and epoxy resin mixture (E-D). The composites were produced by blending with different contents of ammonium polyphosphate (APP) and expandable graphite (EG) into E-D resin, named E-D/A-E composites. Firstly, E-D/A-E blends were analyzed by Fourier transform infrared spectroscopy and DSC to evaluate their curing behavior. The TGA was performed on the E-D/A-E composites to analyze their thermal stability, and the thermal properties of the composites were enhanced by adding APP-EG (A-E) flame retardants. The mechanical properties and the fractured surfaces of the E-D/A-E composites were studied by tensile, impact tests and scanning electron microscopy. Finally, through torch burning test, limiting oxygen index (LOI), vertical burning (UL-94) and micro-calorimetry tests, the influence of A-E flame retardants contents on flammability of composites were evaluated. The results showed that the UL-94 V-0 rating was obtained for the E-D/A-E composites and the composites exhibited a self-extinguishing phenomenon. When A-E flame retardants content reached 9.1 wt%, the LOI value reached 34.5%, and total heat release (Total HR) was reduced by 20.2% compared with E-D/A-E 1. 相似文献