磷酸酯阻燃剂HDP的合成工艺及其在ABS中的阻燃作用

采用新工艺路线合成高熔点磷酸酯阻燃剂———对苯二酚双(二苯基磷酸酯)(HDP).首先采用对苯二酚和三氯氧磷合成中间产物,再将中间产物与苯酚反应,经分离纯化得到产品HDP,收率达到90%以上,常温下为白色固体.采用傅里叶红外光谱、氢谱、磷谱和质谱测试确定了其结构.同时,研究了HDP的阻燃性,并与间苯二酚双(二苯基磷酸酯)(RDP)进行了比较,研究发现当HDP和RDP分别与成炭剂酚醛树脂(NP)按20/10比例添加到丙烯腈-丁二烯-苯乙烯(ABS)树脂中,增强了复合材料凝聚相阻燃作用,极限氧指数(LOI)有所提高.通过热重及锥形量热分析两种复合材料以及各种组分的热降解过程,阻燃剂的添加对ABS树脂的热稳定性和残炭量明显提高,而且ABS/HDP/NP复合材料的抑烟性更好;同时采用扫描电镜(SEM)和X射线能量色散谱(EDS),发现ABS/HDP/NP复合材料燃烧后成炭空隙均匀,其残炭中磷分布比ABS/RDP/NP复合材料残炭中的磷分布更加均匀.研究表明,HDP与NP互配添加到ABS中,在凝聚相阻燃作用优于RDP.     

金属氢氧化物直接制备对苯二甲酸插层水滑石及其应用

以新制备的Mg(OH)_2和Al(OH)_3滤饼与对苯二甲酸通过水热反应制备了对苯二甲酸插层水滑石(TALDHs).使用X射线衍射(XRD)、热重-差热分析、扫描电镜(SEM)等技术对TA-LDHs与碳酸根型水滑石(CO3-LDHs)进行对比研究,结果显示,对苯二甲酸离子成功插入到LDHs层间,产物结构完整、晶相单一,所制得的TA-LDHs为片状.CO3-LDHs和TA-LDHs分别作为纳米填料,以两种不同的添加方式制备聚对苯二甲酸乙二醇酯(PET)/LDHs纳米复合材料.对复合材料进行XRD和SEM研究,结果表明在酯交换反应前添加2%TA-LDHs所制备的PET/LDHs纳米复合材料的层板被部分剥离,分散性最好.     

基于次磷酸铝的聚丙烯木塑复合材料的阻燃改性研究

本研究以次磷酸铝(AP)为阻燃剂,探讨了其对聚丙烯/木粉复合材料(WPC)的阻燃性能的影响,并阐明了相关的阻燃机理。实验结果证明,当AP的添加量为30 wt%时,可以使木粉含量为30 wt%的WPC通过垂直燃烧V-0级,氧指数达到25. 0%。锥形量热测试结果表明:AP的加入能够有效抑制复合材料的燃烧,30wt%AP的加入能够使木粉含量为30 wt%的WPC的热释放峰值(PHRR)降低至240 k W/m~2,与不含阻燃剂的WPC相比降低了50%;燃烧后所得的残炭的质量高达45. 2%。扫描电子显微镜(SEM),热重-红外联用(TGFTIR)和X射线光电子能谱结果表明:添加AP后,燃烧过程中WPC/AP的气相产物中会有水、二氧化碳及含PO_2-结构的物质等生成,从而赋予WPC/AP气相阻燃作用;此外,WPC/AP在燃烧中能够热解生成内外结构不同的炭层,内部炭层主要为含铝为主的交联稳定炭层,而外部炭层主要含有交联P-O-C结构等,因此,AP能够同时通过气相和凝聚相的双重作用实现WPC的高效阻燃。     

六苯氧基环三磷腈的热解及其对环氧树脂的阻燃机理

采用极限氧指数仪和锥形量热仪测试了以六苯氧基环三磷腈(HPCP)阻燃环氧树脂的燃烧性能,结果显示,与纯环氧树脂相比,阻燃环氧树脂的极限氧指数值(LOI)明显提高、热释放速率峰值(pk-HRR)和总热释放量(THR)明显下降、环氧树脂的点燃时间提前以及分解速度加快.采用热失重(TGA)、热重红外联用(TGA-FTIR)、X射线光电子能谱(XPS)和热裂解气相色谱质谱联用(Py-GC/MS)研究了HPCP及其阻燃环氧树脂的热解路线和阻燃机理.结果表明,在阻燃环氧树脂过程中,一方面,HPCP分子中的苯氧基团首先解离并发生歧化反应,由此产生的苯氧基及其歧化产物的焠灭效应在环氧树脂中发挥气相阻燃作用,剩余的磷腈环和苯环基团会进一步裂解产生小分子碎片;另一方面,环氧树脂基体在HPCP的作用下提前分解,产生了基于双酚A结构的大分子碎片并在HPCP裂解产物作用下加速炭化,从而使更多的基体组分以残炭的形式被固定在凝聚相中,提高了阻燃环氧树脂的残炭产率,发挥了凝聚相阻燃作用.     

多价态钼多酸配合物[Mo(Ⅳ)Mo2(Ⅴ)O7(Phen)]的晶体结构及性质

用水热法合成了一种新的多价钼多酸配合物[Mo(Ⅳ)Mo2(Ⅴ)O7(Phen)],并用X射线衍射、元素分析、红外光谱、热重-差热、荧光光谱和磁化率等对其进行了表征.X射线衍射分析表明,配合物晶体属于单斜晶系,P2(1)/c空间群,由十二员环和八员环构成二维网状结构.配合物中强π-π堆积作用构筑成层状三维超分子,稳定了配...     

卡拉胶纤维的阻燃性能

以钡盐为凝固浴, 经湿法纺丝技术获得卡拉胶纤维(CAF). 通过极限氧指数(LOI)、 锥型量热(Cone)、 扫描电子显微镜(SEM)、 元素分析(EDS)、 X射线衍射(XRD)、 热重红外(TG-FTIR)同步差示扫描量热(DSC)法、 热裂解(Py)和气相色谱-质谱法(GC-MS)对CAF进行表征. 结果表明, CAF极限氧指数高达50以上, 锥型量热过程中, CAF一直保持红热状态, 没有产生火苗, 其热释放速率及总释放热等参数均较低, 与海藻酸钙纤维(ALF)和琼胶纤维(AGF)相比, CAF具有较好的阻燃性. 可能机理为卡拉胶分子的硫酸酯基和渗入纤维内部的钡离子发生络合作用, 并促进交联成炭和改变纤维裂解过程. 裂解过程中产生的磺酰自由基与燃烧产生的氢氧自由基迅速结合, 终止燃烧反应. 同时, CAF在燃烧过程中产生大量残炭, 并形成致密的钡盐结构层和中空的纤维结构, 成为CAF阻燃的另一重要因素.     

固体酸催化剂对二甲醚水蒸气重整制氢过程的影响

将 HZSM-5 (n(SiO2)/n(Al2O3) = 25, 38, 50 和 93.5), HM, Hβ, HY 和γ-Al2O3 等多种固体酸催化剂用于二甲醚(DME)水解, 并将其分别同自制的 CuO/ZnO/Al2O3 催化剂进行机械混合, 制备双功能催化剂并用于 DME 水蒸气重整制氢反应. 结合 NH3 程序升温脱附表征手段, 考察了固体酸催化剂酸性位的强度、酸量及种类对 DME 水解和重整反应的影响;结合热重-差热扫描量热分析表征手段, 研究了 HZSM-5(93.5)和γ-Al2O3 在 DME 水解过程中的稳定性. 在此基础上, 进一步研究了固体酸催化剂对 DME 重整制氢反应中 DME 转化率、H2 摩尔产率以及含碳气体产物选择性的影响. 结果表明, 固体酸催化剂的酸性位的强度和酸量对 DME 重整制氢过程具有显著的影响, 强酸度和高酸量无益于 DME 水蒸气重整制氢;以 HZSM-5 为固体酸的双功能催化剂具有较好的低温活性, 而以γ-Al2O3 为固体酸的双功能催化剂在高温下具有较高的 H2 产率.     

DOPO基膦酸铝盐的制备及其阻燃环氧树脂的性能研究

以10-羟基-9-氧杂-10-磷杂菲-10-氧化物(DOPO-OH)和六水合氯化铝为原料合成了一种DOPO基膦酸铝盐(DOPO-Al)阻燃剂,通过红外光谱、扫描电镜、能谱、核磁共振磷谱和热失重表征了其结构,并制备了DOPO-Al阻燃的环氧树脂,通过极限氧指数、锥形量热、热失重和差示扫描量热测试分析了该树脂的阻燃和热性能。结果表明,DOPO-Al为高温阻燃剂,其初始热分解温度(T_(5%))高达595.5℃。DOPO-Al能提高环氧树脂的阻燃性能和耐热性。当DOPO-Al添加量为7.5%(wt)时,环氧树脂的LOI值由24.1%提高至31.3%;在燃烧过程中,使其热释放速率峰值、平均热释放速率、总热释放、总烟释放和总烟产量均降低,使残留物增加幅度高达135%。炭层分析表明DOPO-Al存在凝聚相阻燃机理。环氧树脂的T_(5%)和玻璃化转变温度分别高达368.9℃和161.8℃,所制备阻燃环氧树脂具有较好的热性能。     

耐高温杂化阻燃剂/改性红磷阻燃半芳香尼龙的研究

将自制的耐高温勃姆石@苯基次膦酸铝杂化阻燃剂(BM@Al-PPi)与市售改性红磷(MRP)复配制得一种可用于半芳香尼龙PA6T/DT(HTN)的耐高温高效阻燃体系.保持阻燃剂15 wt%的总添加量不变时,MRP的添加量仅为5 wt%即可赋予HTN垂直燃烧V-0级别,极限氧指数为29.8%.锥形量热测试及其燃烧残余物研究表明,MRP阻燃HTN材料以气相阻燃作用为主,抑制热释放效果不佳且烟释放明显增加;而BM@Al-PPi的凝聚相交联成炭作用可同时抑制热释放与烟释放.结合裂解气相色谱质谱联用(Py-GC-MS)分析,给出了HTN/BM@Al-PPi/MRP体系的阻燃机理.BM@Al-PPi与MRP结合使得残炭质量显著提高,同时兼具气相作用,达到了较好的阻燃效果.     

一种二维多孔窗口型膦酸锆材料的合成及其对不同金属离子的吸附性能

合成了一种二维窗口型膦酸锆材料β-丙氨酸-N,N-双亚甲基膦酸锆(ZrNCP),采用X射线衍射仪、扫描电镜、透射电镜分析了合成产物的相组成和微观结构;利用N2吸脱附试验装置测定了合成产物对不同金属离子的吸附性能,考察了浓度、温度及pH对其吸附性能的影响.结果表明,合成产物内部存在大量分布均匀的微介孔,材料微观形貌为规整片状.随着金属离子半径的增大,ZrNCP对各种金属离子的平衡吸附量(mmol/g)呈逐渐减小趋势.     

Thermal stability and flame-retardancy mechanism of poly(ethylene terephthalate)/boehmite nanocomposites

The thermal stability and flame-retardancy properties of poly(ethylene terephthalate)/nano-boehmite composites (PET/AlOOH) were investigated using composites prepared in situ. Combustion behaviour and flammability were assessed using the limiting oxygen index (LOI) and cone calorimetry. The incorporation of nano-boehmite increased the LOI of PET from 18 to greater than 25. Cone calorimetry showed that the heat release rates and total smoke production values of PET/AlOOH composites were significantly less than those of pure PET. It also showed that PET/AlOOH combustion produced greater quantities of char residues than did PET combustion. These results showed that nano-boehmite is an effective flame-retardant for PET. Combustion residues were examined using scanning electron microscopy, indicating that nano-boehmite addition produced consistent, thick char crusts. Thermal stability and pyrolysis were investigated using thermogravimetric analysis and pyrolysis-gas chromatography-mass spectrometry, showing that thermal stability of PET/AlOOH was superior to that of pure PET, fewer cracking products were produced in nanocomposite combustion than in pure PET combustion, and pyrolysis of the flame-retardant polyester was incomplete. We propose a condensed phase mechanism for the PET/AlOOH flame-retardancy effect.     

Thermal behavior and flammability of epoxy/glass fiber composites containing clay and decabromodiphenyl oxide

Epoxy/glass fiber hybrid composites with organo-montmorillonite (OMMT) and decabromodiphenyl oxide (DBDPO) flame retardants were prepared by vacuum-assisted resin infusion technique. The effects of OMMT and DBDPO on the flammability properties of epoxy/glass fiber hybrid composites were evaluated through UL-94 vertical flammability test and limiting oxygen index (LOI). Thermal decomposition was studied by means of thermogravimetric analyzer (TG). Field emission scanning electron microscopy (FESEM) was used to study the char morphology of the epoxy hybrid composites after being subjected to UL-94 vertical flammability test. Epoxy/glass fiber/OMMT hybrid composites with DBDPO loading of 40 wt% showed V-1 rating, whereas an increase to 50 wt% loading showed V-0 rating. The LOI values increased from 22.7 to 39.9 % as the loading of DBDPO increased. The obtained TG results showed that the thermal stability of epoxy hybrid composites decreased as the DBDPO loading increased. DBDPO decomposed at a lower temperature to form bromine radicals, which reacted with the combustible gases to form hydrogen bromide to inhibit the flame spread in the gas phase. The condensed phase activity was shown in FESEM, in which a layer of compact and continuous char was formed in epoxy/glass fiber/OMMT/DBDPO hybrid composites.     

Mechanical, thermal, and fire properties of polylactide/starch blend/clay composites

Polylactide (PLA)/starch blend/clay and PLA/clay composites are prepared by melt blending. Structural and thermal characterizations are performed by differential scanning calorimetry, X-ray diffraction analysis, and thermogravimetric analysis. The fire properties are assessed on a dual cone calorimeter. Combustion residue and char formation is characterized by optical microscopy and attenuated total reflection infrared spectroscopy. Although the clay is not fully intercalated/exfoliated, the composites exhibit a higher thermal stability and much reduced peak heat release rate, and the PLA/starch blend composite retains its mechanical properties. For the PLA/starch blend composite, smoke release is also considerably reduced. Catalyzed, oxidative decomposition is shown to occur early in the thermal decomposition of the composites, prior to increased thermal stability. The inclusion of clay promotes char formation and increases the quantity of carbonaceous char in the combustion residue. There is minimal migration of the clay to the surface prior to ignition and char is formed mainly after ignition and during burning. During the later stages of burning some of the char formed is converted to CO₂.     

Synergistic flame‐retardant effect of DOPO‐based derivative and organo‐montmorillonite on glass‐fiber‐reinforced polyamide 6 T

Herein, a bridged 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO) derivative (PN‐DOPO) in combination with organ‐montmorillonite (OMMT) was used to improve the flame retardancy and mechanical properties of glass‐fiber‐reinforced polyamide 6 T (GFPA6T). The flame retardancy and thermal stabilities of the cured GFPA6T composites were investigated using limiting oxygen index, vertical burning (UL‐94) test, cone calorimeter test, and thermogravimetric analysis (TGA). The morphological analysis and chemical composition of the char residues after cone calorimeter tests were characterized via scanning electron microscopy and energy dispersive spectrometry. The results indicate that 2 wt% OMMT combined with 13 wt% PN‐DOPO in GFPA6T achieved a V‐0 rating in UL‐94 test. The peak heat release rate and total smoke release remarkably decreased with the incorporation of OMMT as compared to those of GFPA6T/15 wt% PN‐DOPO. The TGA results show that the thermal stability and residual mass of the samples effectively increased with the increase in OMMT content. The morphological analysis and composition structure of the residues demonstrate that a small amount of OMMT could help form a more thermally stable and compact char layer during combustion. Also, with the incorporation of OMMT, the layers consisted of more carbon‐silicon and aluminum phosphate char in the condensed phase. Furthermore, GFPA6T/PN‐DOPO/OMMT composites exhibited excellent mechanical properties in terms of flexural modulus, flexural strength, and impact strength than the GFPA6T/PN‐DOPO system. The combination of PN‐DOPO and OMMT has improved the flame retardancy and smoke suppression of GFPA6T without compromising the mechanical properties.     

膨胀阻燃硬质聚氨酯泡沫塑料热降解及燃烧产烟研究

采用热失重、X-射线光电子能谱分析、氧指数及烟密度测试等方法研究了可膨胀石墨(EG)与聚磷酸铵(APP)复配膨胀阻燃硬质聚氨酯泡沫塑料(RPUF)的热降解、燃烧性能及产烟行为.在此基础上利用锥形量热仪考察了EG/APP对磷酸三(β-氯异丙基)酯(TCPP)阻燃RPUF体系燃烧性能的影响.研究表明,EG与APP间的相互作用导致了EG/APP体系高温阶段失重速率下降、残炭量显著上升;EG/APP与RPUF之间的成炭作用以APP的化学成炭为主.与RPUF比较,RPUF/EG/APP的氧指数由19.8%提高至35.4%的同时,烟密度没有显著上升.对比EG、APP及EG/APP阻燃RPUF,体系残炭量越高、炭层耐热氧化能力越强,氧指数就越大;残炭表面越致密,产烟量就越少.添加EG/APP可显著降低含卤体系RPUF/TCPP的热释放、烟释放及CO释放速率,体现了EG与APP复合体系物理与化学膨胀结合的优势.     

Flame retardant and mechanism of vinyl ester resin modified by octaphenyl polyhedral oligomeric silsesquioxane

Flamability is one of the major issues for utilization of bisphenol A–type vinyl ester resin (VER) polymeric composites in practical applications. The thermal stability and mechanical property of VER composites containing octaphenyl polyhedral oligomeric silsesquioxane (OPS) were investigated and discussed in detail. With increasing the mass ratio of OPS, the residues yield at 800°C and bending strength at break of the VER/OPS composites were enhanced, accompanied with the gradually decreased values of the peak heat release rate, total heat release, and total smoke release due to the formation of dense carbon/silica protective layers that acted as a barrier to heat and mass transfer. In addition, the flame‐retardant mechanisms of condensed phase and gas phase were analyzed by XPS, TGA‐FTIR, and GC‐MS. The results showed that when OPS was incorporated to the resin matrix, the characteristic peaks intensity of the gaseous products was reduced obviously due to some of the characteristic groups still retained in condensed phase. Therefore, the significance of this work is providing an optional method to fabricate flame‐retarding VER composites with excellent mechanical properties.     

Preparation of Poly(phosphoric acid piperazine) and Its Application as an Effective Flame Retardant for Epoxy Resin

A phosphorus-nitrogen containing flame retardant additive of poly(phosphoric acid piperazine),defined as PPAP,was synthesized by the salt-forming reaction between anhydrous piperazine and phosphoric acid,and the dehydration polymerization under heating in nitrogen atmosphere.Its chemical structure was well characterized by Fourier transform infrared (FTIR) spectroscopy,13C and 31p solid-state nuclear magnetic resonance measurements.The synthesized PPAP and curing agent m-phenylenediamine were blended into epoxy resin (EP) to prepare flame retardant EP thermosets.The effects of PPAP on the fire retardancy and thermal degradation behavior of cured EP/PPAP composites were investigated by limiting oxygen index (LOI),vertical burning (UL-94),thermogravimetric analysis/infrared spectrometry (TG-IR) and cone calorimeter tests.The morphologies and chemical compositions of char residues for cured epoxy resin were investigated by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS),respectively.The results demonstrated that the flame retardant EP thermosets successfully passed UL-94 V-0 flammability rating and the LOI value was as high as 30.8％ when incorporating 5wt％ PPAP into the EP thermosets.The TGA results indicated that the synthesized PPAP flame retardant additive possessed high thermal stability and excellent charring capability.Meanwhile,the incorporation of PPAP stimulated the epoxy resin matrix to decompose and charring ahead of time due to its catalytic decomposition effect,which led to a higher char yield at high temperature.The morphological structures and the analysis results of XPS for char residues of EP thermosets revealed that the introduction of PPAP benefited the formation of a sufficient,more compact and homogeneous char layer containing phosphorus-nitrogen flame retardant elements on the material surface during combustion.The formed char layer with high quality effectively prevented the heat transmission and diffusion,limited the production of combustible gases,and inhibited the emission of smoke,leading to the reduction of heat and smoke release.     

Effect of aluminum diethylphosphinate on flame retardant and thermal properties of rigid polyurethane foam composites

Rigid polyurethane foam/aluminum diethylphosphinate (RUPF/ADP) composites were prepared by one-step water-blown method. Furthermore, scanning electron microscope (SEM), thermal conductivity meter, thermogravimetric analysis (TGA), limiting oxygen index, Underwriters Laboratories vertical burning test (UL-94) and microsacle combustion calorimetry were applied to investigate thermal conductivity, thermal stability, flame retardancy and combustion behavior of RPUF/ADP composites. Thermogravimetric analysis–Fourier transform infrared spectroscopy (TG–FTIR) was introduced to investigate gaseous products in degradation process of RPUF/ADP composites, while SEM and X-ray photoelectron spectroscopy were used to research char residue of the composites. It was confirmed that RPUF/ADP composites presented well cell structure with density of 53.1–59.0 kg m^?3 and thermal conductivity of 0.0425–0.0468 W m^?1 K^?1, indicating excellent insulation performance of the composites. Flame retardant test showed that ADP significantly enhanced flame retardancy of RPUF/ADP composites, RPUF/ADP30 passed UL-94 V-1 rating with LOI of 23.0 vol%. MCC test showed that ADP could significantly decrease peak of heat release rate (PHPR) of RPUF/ADP composites. PHPR value of RPUF/ADP20 was decreased to 158 W g^?1, which was 21.8% reduced compared with that of pure RPUF. TG–FTIR test revealed that the addition of ADP promoted the release of CO₂, hydrocarbons and isocyanate compound in first-step degradation of RPUF matrix while inhibited the release of CO in second step degradation. Char residue analysis showed that the addition of ADP promoted polyurethane molecular chain to form aromatic and aromatic heterocyclic structure, enhancing strength and compactness of the char. This work associated a gas–solid flame retardancy mechanism with the incorporation of ADP, which presented an effective strategy for preparation of flame retardant RPUF composites.

     

The effects of wood-flour on combustion and thermal degradation behaviors of PVC in wood-flour/poly(vinyl chloride) composites

The effects of wood-flour on combustion and thermal degradation behaviors of PVC in wood-flour/poly (vinyl chloride) composites (WF-PVC) were investigated by using cone calorimeter (CONE) and TGA. The results show that thermal degradation behavior of WF-PVC composites has obvious characteristics of that of PVC. Interactions occur between wood-flour and PVC during the combustion and thermal degradation of WF-PVC composites. The thermal degradation of wood-flour can be accelerated by pure PVC. Moreover, the char formation can be raised by adding wood-flour to PVC. Compared with PVC at all flaming stage, when heat flux is kept at 50 kW m⁻², the average heat release rate (av-HRR), the total heat release (THR), the total smoke production (TSP) and the average specific extinction area (av-SEA) of WF-PVC composites are respectively reduced by 44%, 9.2%, 25.8% and 29.9%. In WF-PVC composites, the wood-flour has remarkable effects on the properties of heat release and smoke release of PVC.     

磷化淀粉的合成及其与聚磷酸铵协效阻燃聚乳酸的性能研究

利用9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物(DOPO)和马来酸酐(MA)对淀粉进行改性得到磷化淀粉(DOPOMASt),通过红外光谱(FTIR)、核磁共振谱(1H-NMR)和X射线光电子能谱(XPS)确定其结构.利用DOPOMASt作为碳源,与聚磷酸铵(APP)复配后通过熔融共混制备了阻燃聚乳酸(PLA)...