Environmental issues related to end‐of‐life options of plastics containing brominated flame retardants

Bromine is used as the building block for some of the most effective flame retarding agents available to the plastics industry today. They are used to protect against the risk of accidental fires in a wide range of Electrical and Electronic Equipment (EEE). Brominated flame retardants (BFRs), as all flame retardants, act to decrease the risk of fire by increasing the fire resistance of the materials in which they are applied. There is a perception that BFRs affect adversely the end‐of‐life management of plastics through formation of Polybrominated Dibenzo Dioxins and Dibenzo Furans (PBDD/F). In fact, there exists a wide range of data and practical experience demonstrating that the end‐of‐life management of plastics containing BFRs is fully compliant with legislation setting the strictest limit values for PBDD/F and is fully compatible with an integrated waste management concept. Copyright © 2004 John Wiley & Sons, Ltd.     

国内溴化聚苯乙烯阻燃剂合成技术进展

针对提高产品质量,降低成本,提高生产效率,从工艺和设备方面综述了国内溴化聚苯乙烯阻燃剂合成技术进展。     

塑料阻燃剂的合成研究进展

通过对常用塑料的燃烧特性和阻燃剂的阻燃机理的分析,论述了卤系、聚合型有机磷系、磷—氮系和无机系等不同类型阻燃剂的阻燃特性、发展动向及几种具有发展前途的新型阻燃技术,指出无卤、高效、低烟、低毒、多功能的新型阻燃剂合成及其新型阻燃技术的研究是阻燃剂的发展方向。     

塑料中无机阻燃剂的研究进展

介绍了无机阻燃剂的阻燃机理,总结了塑料中各种无机阻燃剂的研究现状及其应用,并就其优缺点进行分析。     

膨胀型阻燃剂及其在塑料中的应用研究进展

介绍了膨胀型阻燃剂（IFR）的组成、阻燃机理、种类及以及处理技术,概述了膨胀型阻燃剂在塑料中的应用研究进展,指出了其今后的发展趋势。     

电子电器产品中含溴阻燃剂的萃取

电子电器产品中含溴阻燃剂的萃取方法有索氏萃取、自动索氏萃取、超声波萃取、超临器萃取、微波辅助萃取和快速溶剂萃取等.文章通过对比索氏萃取、微波辅助萃取和快速溶剂萃取并结合高效液相色谱法测定电子塑料产品中的含溴阻燃剂,探讨合适的萃取方法,实验结果表明,索氏萃取效果最好,回率91.8%～98.4%,RSD%=5,满足检测要求...     

溴系阻燃塑料的回收再利用

介绍了回收利用溴系阻燃塑料的3种方法:①机械回收;②焚烧以回收能量;③焚烧或裂解以回收溴或氢溴酸。分析回收过程的环保问题。评述了机械法和焚烧法在技术上、生态上和经济上都是可行和安全的,但应采用合理的焚烧工艺,并严格控制和监测二口恶英的产生和释出。     

阻燃剂阻燃机理的探讨

本文介绍了一般阻燃剂主要通过吸热冷却、气相稀释、形成隔热层和终止自由基链反应等途径,来实现对材料的阻燃。同时也相应的阐述了无机阻燃剂、有机阻燃剂以及膨胀型阻燃剂的阻燃特性及机理。     

高分子阻燃剂溴化聚苯乙烯的应用

以高分子溴化聚苯乙烯(BPS)协同三氧化二锑(Sb2O3)作为复合阻燃剂,对聚对苯二甲酸丁二醇酯(PBT)进行改性。研究了复合阻燃剂对PBT的燃烧性能,电性能及力学性能的影响。结果表明,复合阻燃剂BPS/Sb2O3对PBT具有良好的阻燃效果,对其电性能影响很小,少数力学性能有所下降。在PBT中添加BPS/SbO复合阻燃剂的质量分数为20%时,阻燃PBT的垂直燃烧达到FV-0级。     

Synthesis of bromo‐cardanol novolac resins and evaluation of their effectiveness as flame retardants and adhesives for particleboard

The synthesis of bromo derivatives cardanolic novolac resins (BCNR) using infrared, thermogravimetric analysis, differential scanning calorimetry, gel permeation chromatography, nuclear magnetic resonance ¹H and ¹³C methods was studied. The mechanism of thermal degradation of BCNR is proposed. It is shown, that particleboards manufactured using PU‐(BCNR) as an adhesive are materials with enhanced flame retardant properties, meeting the requirements of P7 class to EN 312 (especially durable moisture‐resistant particleboards) and the requirements of the emission class Super E0. The bromine in the structure of the cardanol‐containing polyurethane binder allows achieving both high physical and mechanical characteristics of the particleboards and resistance to flame. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45322.     

Fire performance of brominated and halogen‐free flame retardants in glass‐fiber reinforced poly(butylene terephthalate)

This paper investigates the effects of brominated and halogen‐free fire retardants on the fire performance of glass‐fiber (GF) reinforced poly(butylene terephthalate) (PBT). Brominated polystyrene was used as the brominated fire retardant, whereas aluminum diethylphosphinate with/without nanoclay as halogen‐free fire retardants (HFFRs). Tests were conducted by using thermogravimetric analysis, limiting oxygen index (LOI), UL94, and the cone calorimeter. Thermogravimetric analysis results show that decomposition of GF plus PBT (PBT + GF) starts earlier in the presence of all fire retardants (FRs). In the cone calorimeter, all FRs reduce significantly the heat release rate (HRR) compared with PBT + GF, with brominated polystyrene achieving lowest HRR primarily because bromine released in the pyrolysis gases inhibits combustion. Brominate polystyrene does not, however, affect the mass loss rate. Aluminum diethylphosphinate alone has significant effects on reduction of both HRR and mass loss rate, which become considerably more when combined with nanoclay. It was also found that the combustion efficiency of the brominated polystyrene compound is much lower than that of HFFRs, indicating that brominated polystyrene has higher gas phase flame retardant efficiency compared with HFFRs because the bromine radicals released during degradation of brominated polystyrene effectively quench the chemical reactions of the pyrolysis gases due to degradation of PBT.     

GC/MS检测电子电气产品中的溴系阻燃剂

建立了用于7种多溴联苯醚（PBDE）和四溴双酚A（TBBPA）废旧电子电器产品塑料及线路板中溴代物阻燃剂的气相色谱-质谱联用的快速检测方法。本方法分离时间短,定性定量准确,操作简便,实用性强,检出限低,适用于废旧电子电气产品（电话机壳、计算机壳和电视机壳以及电路板）中的塑料回收过程中溴代物阻燃剂的鉴别与分析。     

有机硅阻燃剂协同阻燃作用的研究进展

论述了有机硅阻燃剂与卤系[如四溴双酚A双(2,3-二溴丙基)醚]、磷系(如聚磷酸铵)、无机系(如氢氧化铝和氢氧化镁)阻燃剂以及某些非阻燃物质(如硬脂酸盐、沥青、硅酸钾、二碱式亚磷酸铅、三碱式硫酸铅、碳酸钙等)协同阻燃的研究状况、发展趋势和应用前景。     

Phosphorus esters of 1-dopyl-1,2-(4-hydroxyphenyl)ethene as effective flame retardants for polymeric materials

1-Dopyl-1,2-(4-hydroxyphenyl)ethene has been converted to phosphorus diesters, 1-dopyl-1,2-(4-diphenylphosphatophenyl)ethene (BDE-DPP), and 1-dopyl-1,2-(4-dopyloxyphenyl)ethene (BDE-DOPO) which have been fully characterized using spectroscopic and thermal methods and assessed as flame retardants in DGEBA epoxy (diglycidyl ether of bisphenol A). Both are effective flame retardants. The ester containing diphenylphosphato groups (BDE-DPP) acts primarily in the condensed phase while that containing only dopyl units acts predominately in the gas phase. DGEBA epoxy containing sufficient 1-dopyl-1,2-(4-dopyloxyphenyl)ethene to provide 2% phosphorus displays a limiting oxygen index of 28, a peak heat release rate of 506 W/g, and a total heat release of 24 kJ/g.     

Chemical recycling of polymers from Waste Electric and Electronic Equipment

This research is focused on the recycling of three types of polymers, namely polycarbonate (PC), poly(acrylonitrile‐butadiene‐styrene) (PABS), and polystyrene (PS) from Waste Electric and Electronic Equipment (WEEE). Initially, the chemical structure of each polymeric material in a variety of WEEE was identified by Fourier Transform Infra Red (FTIR) spectroscopy and Differential Scanning Calorimetry (DSC). The potential recycling of these polymers from these wastes was examined by employing two different approaches, the dissolution/reprecipitation method and the more challenging technique of pyrolysis. During the first, the polymer is separated and recycled through a solvent/non‐solvent system. It is a simple and economic technique leading to high recovery of pure polymer. Both, model polymers and plastic parts from WEEEs were studied and optimum experimental conditions, including dissolution temperature and time, polymer concentration and type of solvent were proposed to achieve significant recovery of the polymer (>90 wt %). Furthermore, pyrolysis of waste Compact Disks (CD) was investigated and compared with model poly(bisphenol A carbonate) (PC) through a laboratory‐scale fixed bed reactor. The appropriate pyrolysis temperature was selected after measuring the thermal degradation of model PC by Thermogravimetric analysis (TGA). A large amount of oil was measured, together with a smaller amount of gaseous product, leaving also a solid residue. For both samples, the gaseous fraction consisted mainly of CO₂ and CO whereas in the liquid fraction a large amount of different phenolic compounds, including the monomer bisphenol A, was measured. It seems that recycling of used CDs by pyrolysis is a very promising technique having the potential of producing useful high‐value chemicals, which may find applications in the petrochemical industry. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Synthesis of phosphorus-containing flame retardants and investigation of their flame retardant behavior in textile applications

Flame retardants are a growing area of research interest. Nonhalogenated, durable, and nonleachable flame retardants are one of the main strategies used in the research of flame retardant polymers. In this regard, the covalent attachment of phosphorus-containing flame retardants onto cotton fabric has been developed. Two types of reactive phosphorus-containing flame retardants (MKT-1 and MKT-2) have been synthesized and used as a surface coating for cotton fabric. MKT-1 possesses anhydride and acid functionalities that can react with the  OH functionalities in cellulose. In addition, MKT-2 has both acid and organosilicon groups that can also react with the hydroxy group present in cellulose. The structures of the reactive flame retardants (MKT-1 and MKT-2) were characterized using ¹³C and ³¹P nuclear magnetic resonance spectroscopy. Thermal properties of the coated and uncoated cotton fabrics were investigated using thermogravimetric analysis. Surface characterization was carried out using scanning electron microscopy and X-ray photoelectron spectroscopy. A standard test method used to evaluate the flammability of blankets (BS 5852) was also applied to characterize the fire retardant properties of the coated and uncoated cotton fabrics studied. Different loadings of MKT-1 and MKT-2 on the fabric (10, 20, and 30% by weight in dimethylformamide solution) were applied in the dip coating process. The cotton fabric coated with 30% MKT-2 does not burn after being subjected to a propane burner for 20 s and also produced the highest char yield (36%) at 500 °C. Inductively coupled plasma–optical emission spectrometry showed that MKT-1 contains 8.23 ± 0.33 P% whereas MKT-2 contains 3.88 ± 0.15 P%. Although MKT-1 possess a higher P content than MKT-2, the additive effect caused by the organosilicon and nitrogen groups present in MK-2 enhance its flame retardant properties. Furthermore, the covalently attached flame retardant materials are durable and do not hydrolyze during washing. The mechanical properties of coated fabrics were characterized by a tensile test and significant change in elongation at break was observed. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47935.     

Optimization of activated carbon‐based decontamination of fish oil by response surface methodology

The effect of activated carbon (AC) adsorption on the reduction of persistent organic pollutants (POP) in fish oil was studied based on response surface methodology at a 5‐g/kg AC inclusion level. Pretreatment of the oil by alkali refining and bleaching increased the POP levels. The tested process variables (contact time and temperature) affected the AC adsorption rate and significant first‐ and second‐order response models could be established. Polychlorinated dibenzo‐p‐dioxins and dibenzofurans (PCDD/F) showed a very rapid adsorption behavior and the concentration and toxic equivalent (TEQ) level could be reduced by 99%. Adsorption of dioxin‐like polychlorinated biphenyls (DL‐PCB) was less effective and depended on ortho substitution, i.e. non‐ortho PCB were adsorbed more effectively than mono‐ortho PCB with a maximum of 87 and 21% reduction, respectively, corresponding to a DL‐PCB‐TEQ reduction of 73%. A common optimum for both PCDD/F and DL‐PCB adsorption could not be identified. AC treatment had no effect on the level of polybrominated diphenyl ether flame retardants. The differences in adsorption patterns may be explained based on molecular conformation. No change in oil quality could be observed based on oxidation parameters. Compliance with present PCDD/F and DL‐PCB legislation levels in fish oil can be achieved based on AC adsorption.     

应用于PA6工程塑料的氮系阻燃剂的研究现状

氮系阻燃剂因高效的阻燃性能及分解产物低毒的特点被广泛应用于PA6工程塑料的阻燃中。文章综述了近年来应用于PA6工程塑料的氮系阻燃剂的研究及应用现状,并介绍了存在的问题及相应的解决方法,对应用于PA6的氮系阻燃剂的发展做出展望。     

氮系阻燃剂的研究及应用概况

氮系阻燃剂高效且本身及其分解产物低毒,成为当今阻燃剂的发展方向。文中概述了氮系阻燃剂及氮-磷复合阻燃剂的特点、分类及其阻燃机理,归纳了该阻燃体系在环氧树脂、不饱和聚酯树脂、酚醛树脂、聚乙烯和聚氨酯等体系中的应用概况,并指出了今后的发展方向。     

Effects of titanium dioxide on the flammability and char formation of water-based coatings containing intumescent flame retardants

Rutile-type TiO₂ (r-TiO₂) or anatase-type TiO₂ (a-TiO₂) in association with a conventional intumescent flame retardant system which contains ammonium polyphosphate/pentaerythritol/melamine (APP–PER–MEL) was introduced to silicone-acrylate coatings to improve the fire resistance. The effect of TiO₂ on the fire-resistance and thermal properties of APP–PER–MEL coating has been investigated by using big panel method and thermogravimetry (TG). The limit of fire-resistance of the sample containing 30 phr rutile-type TiO₂ (73 min) is much longer than that of the sample containing 30 phr anatase-type TiO₂ (34 min). The morphology and structure of charring layers were studied by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The relationship between charring process and melt flow rate (MFR) of silicone-acrylate was also discussed. It is suggested that MFR value can significantly affect the formation of char, and a moderate silicone-acrylate MFR is required to form good quality char.