Evaluation of various fire retardants for use in wood flour-polyethylene composites

Wood-plastic composites represent a growing class of materials used by the residential construction industry and the furniture industry. For some applications in these industries, the fire performance of the material must be known, and in some cases improved. However, the fire performance of wood-plastic composites is not well understood, and there is little information regarding the effectiveness of various fire retardants in the public domain. We used oxygen index and cone calorimeter tests to characterize the fire performance of wood flour-polyethylene composites, and compared the results with unfilled polyethylene and solid wood. We then evaluated the effect of five additive-type fire retardants on fire performance. Generally, magnesium hydroxide and ammonium polyphosphate improved the fire performance of WPCs the most while a bromine-based fire retardant and zinc borate improved fire performance the least.     

凝胶渗透色谱结合气相色谱-负化学源质谱法分析鱼肉及鱼油中的多溴联苯醚和得克隆阻燃剂

建立了凝胶渗透色谱(GPC)结合气相色谱-负化学源质谱(GC-NCI/MS)检测鱼肉及鱼油中8种多溴联苯醚(PBDEs)同系物及2种得克隆阻燃剂(DP)的分析方法。试样中加入内标物BDE-77和13C12-BDE-209后进行索氏提取,提取液经自动GPC系统除脂,多层硅胶层析柱净化后,在15 m长的毛细管气相色谱柱上分离,NCI/MS以选择离子监测方式检测目标化合物。以鱼肉样品为基质,当PBDEs的加标水平为0.2 ng/g和2 ng/g、BDE-209和DP的加标水平相应提高10倍时,其平均加标回收率为71.1%～121.4%,相对标准偏差为2.96%～13.31%(n=5);以信噪比(S/N)为3计算方法的检出限(LOD)为2.2～39.8 ng/kg。用该方法检测市售鱼肉及鱼油样品,其中多溴联苯醚总含量为2.18～15.93 ng/g,以BDE-209、BDE-47为主,两种DP均未检出。该方法准确、灵敏度高,能够满足富含脂质的动物性样品中痕量DP和PBDEs残留的分析要求。     

Continuous hydrothermal synthesis of AlO(OH) nanorods as a clean flame retardant agent

Aluminum-oxide-hydroxide (AlOOH) is a clean and non-toxic flame retardant. There have been many trials for the fabrication of ultrafine AlOOH. Two main approaches exist for nano-AlOOH synthesis: reactive precipitation and batch hydrothermal synthesis. Both approaches are laborious and time consuming with poor control of particle morphology. We report on the novel continuous flow manufacture of AlOOH nanorods with controlled morphology (particle size and shape) by hydrothermal synthesis. AlOOH was harvested from its mother liquor (colloidal solution) using poly(acrylamide-co-acrylic acid) copolymer as a flocculating agent. The developed AlOOH shape and size, crystalline phase, thermal stability, and endothermic heat sink action were investigated by transmission electron microscopy, X-ray diffractometry, thermogravimetric analysis, and differential scanning calorimetry, respectively. The phase transition of AlOOH to Al₂O₃ was demonstrated by conducting different X-ray diffractometry scans from 400 to 700 °C. These results may provide an option for the continuous synthesis of nano-AlOOH as a clean and non-toxic flame retardant with excellent thermal stability. Consequently, enhanced flammability properties can be achieved at low solids loading.     

电拓扑状态预测有机磷酸酯类化合物的气相色谱保留指数

以原子类型电拓扑状态指数(ETSI)有效表征35个有机磷酸酯类化合物(OP)的分子结构, 应用基于预测的变量选择与模型化(VSMP)方法建立OP化合物在3种不同固定相上的气相色谱保留指数(RI)与分子结构(ETSI)的定量相关模型. 结果表明, 影响不同固定相上OP色谱保留的主要结构因素都是由7个ETSI描述子对应的子结构碎片, 即: ＝CH₂,≡C—, aaC—, ＝O, —O—, Cl和Br. 其中子结构aaC—, ＝O和—O与OP化合物母体骨架密切相关, 而＝CH₂,≡C—, —Cl和—Br反映支链或取代基的变化. 通过多元线性回归法建立OP化合物在三个固定相上的定量结构-保留相关模型(QSRR)发现, 各QSAR模型的估计相关系数均在0.99以上, LOO检验相关系数在0.98以上, 表明模型具有良好估计能力与稳定性. 应用28个OP训练集样本构建的QSRR模型预测外部7个检验集RI结果表明训练集模型具有良好预测能力.     

阻燃剂废水的处理研究

阻燃剂生产过程中产生大量的工业废水,通过对比处理实验研究表明：电解Fenton法是处理阻燃剂生产中产生的高浓度有机废水（CODCr=17108mg／L）的有效方法,它既利用了电氧化、电气浮作用,又利用了Fenton试剂的强氧化作用和化学絮凝作用。其处理废水的条件实验结果表明：pH：2．0～2．6;电流密度10．8～14．3A/dm^2;H2O2初始浓度27～42mmol／L;FeSO4初始质量浓度660～990mg／L;电解5h。CODCr去除率达98．34％,色度去除率达74．19％。色质联用分析显示废水处理后的降解产物是无毒害的醋酸。     

Studies of degradation enhancement of polystyrene by flame retardant additives

Experimental methods as well as thermodynamic modeling techniques were utilized to explore potential gas and condensed-phase contributions of various flame retardant (FR) additives with polystyrene polymer. FR additives investigated include hexabromocyclododecane (HBCD), triphenyl phosphine oxide (TPPO), triphenyl phosphate (TPP), triphenyl phosphine sulfide (TPPS), and sulfur. Flame studies of fundamental FR activity were also employed using molecular beam mass spectrometry analysis of FR active species directly in a flame system. The flame studies show direct evidence for active bromine (HBr, Br) species for HBCD and active phosphorous species (HPO₂, PO, PO₂ HPO₃) species for TPPO and TPP which provide high potential for gas-phase activity for these FR additives. Various experimental measurements were also done to assess the degradation species and the degree of degradation of polystyrene by the FR additives. These studies support enhanced degradation of the base polystyrene polymer by the FR additive as a major pathway for condensed FR activity for HBCD and sulfur FR additives. Phosphorous based structures appear to show little enhancement of polystyrene degradation.     

Thermal properties of poly(styrene) containing brominated aryl phosphate additives

General purpose poly(styrene) is a large volume commodity polymer widely used in a range of applications. For many of these the presence of an additive to impart some flammability resistance is required. Most commonly, brominated aromatics are used for this purpose. As the polymer undergoes combustion these compounds decompose to generate bromine atoms and/or hydrogen bromide which escape to the gas phase and trap flame propagating radicals. While these species are effective in inhibiting flame propagation they present the opportunity for loss of halogen to the atmosphere. For this reason, the use of these compounds is being limited in some parts of the world. Phosphorus compounds, on the other had, impart a flame retarding influence by promoting char formation at the surface of the burning polymer. This prevents heat feedback to the polymer and consequent pyrolysis to generate fuel fragments. The combination of both bromine and phosphorus present in a single compound might generate a superior flame-retarding additive in that both modes of retardancy might be promoted simultaneously. Should this be the case smaller amounts of additive might be necessary to achieve a satisfactory level of flame retardancy. A series of such additives, brominated aryl phosphates, has been synthesized and fully characterized spectroscopically. Blends of these additives, at various levels, with poly(styrene) have been examined by DSC, TG and in the UL-94 flame test. The flammability of the polymer is dramatically diminished by the presence of the additive.     

Imidazolium chloride organophosphate antidotes

The structures of four imidazolium oxime derivatives were solved by direct methods. These compounds have been shown to be effective in the treatmen of organophosphate poisoning. Despite substantial differences in the nature of the substituent on N1, all four compounds have similar shapes when viewed down the plane of the imidazole ring. The potency of these compounds in the treatment of organophosphate poisoning correlates well with the distance between the imidazole ring and the oxygen moiety on the side chain. 2-(hydroxyimino)methyl-3-methyl-1-[1-(3-methyl-sulfonylpropyloxy) methyl]imidazolium chooride (1) crystallizes in the triclinic space groupPī (Z=2). The unit cell parametersa, b, c (Å) and α, β, and γ (^o) were: 8.506(2), 8.787(4), 10.070(4), 73.68(3), 81.37(3), 85.39(3). 2-(hydroxyimino)-methyl-3-methyl-1-(2′-N-phenylsulfonylamino-1′-ethyl) imidazolium chloride (2) crystallizes in the monoclinic space groupP2 ₁ la(Z=4). The unit cell parametersa, b, c (Å) and β (^o) were: 12.690(2), 6.317(4), 20.193(4), 91.47(2). 1-(2′-ethyl-2′-trifluoromethanesulfonyl-aminoethyl)-2-(hydroxyimino) methyl-3-methylimidazolium chloride (3) crystallizes in the triclinic space groupPī (Z=2). The unit cell parametersa, b, c (Å) and α, β, and γ (^o) were: 6.635(1), 11.333(2), 12.274(3), 115.05(3), 98.46(3), 90.11(3). 2-(hydroxyimino)-methyl-3-methyl-1-[2-(2-methyl-3-nitrobutyloxy) methyl]-imidazolium chloride (4) crystallizes in the orthorhombic space groupP2₁2₁2₁ (Z=4). The unit cell parametersa, b, andc (Å) were: 10.034(1), 11.401(2), 13.352(2).     

Determination of organophosphate flame retardants in soil and fish using ultrasound‐assisted extraction,solid‐phase clean‐up,and liquid chromatography with tandem mass spectrometry

A solid–liquid extraction method in combination with high‐performance liquid chromatography and tandem mass spectrometry was developed and optimized for extraction and analysis of organophosphorus flame retardants in soil and fish. Methanol was chosen as the optimum extraction solvent, not only in terms of extraction efficiency, but also for its broader analyte coverage. The subsequent clean‐up by solid‐phase extraction is required to eliminate matrix coextractives and reduce matrix effects. Recoveries of the optimized method were 50–121% for soil and 47–123% for biota, both with high precision (RSDs <12% in soil and <23% in biota). The method limits of detection ranged from 0.06 to 0.20 ng/g dry weight and between 0.02 and 0.30 ng/g wet weight for soil and biota samples, respectively. However, samples with a high lipid content produce several problems as solid‐phase extraction cartridge clogging that increase variability and analysis time. The method was successfully applied for the determination of organophosphorus flame retardants in soil and fish from L'Albufera Natural Park (Valencia, Spain). Target compounds were detected in all soil and fish samples with values varying from 13.8 to 89.7 ng/g dry weight and from 3.3 to 53.0 ng/g wet weight, respectively.     

动物肝脏中九种多溴联苯醚残留量的GC—NCI／MS分析

建立了动物肝脏中9种PBDEs残留量的气相色谱-负化学离子源/质谱(GC-NCI/MS)的分析方法。动物肝脏样品经V(正己烷)∶V(丙酮)=1∶1超声辅助提取,中性与酸性硅胶层析柱净化和V(正已烷)∶V(CH2Cl2)=1∶1洗脱和浓缩后,以PCB-103为内标物,采用GC-NCI/MS的选择离子监测方式(SIM)对其中的9种PBDEs残留量进行了定性与定量分析。当动物肝脏空白样品的加标质量浓度为5.0、20.0μg/kg(PBDE-183为6.0、24.0μg/kg)时,9种PBDEs的平均加标回收率为75.1%~88.2%,相对标准偏差为3.3%~7.9%,方法检出限均小于0.07μg/kg;线性范围除PBDE-183为0.12~600.0μg/kg外,其余8种PBDEs为0.1~500.0μg/kg,相关系数都大于0.9993。所建立的分析方法已用于5种动物肝脏的8个样品中9种PBDEs残留量的分析。