纳米znsn(oh)6对软质pvc阻燃和抑烟性能的影响

分别采用氧指数法、烟密度测试、热重分析和扫描电镜分析等评价了纳米羟基锡酸锌颗粒对软质PVC阻燃和抑烟性能的影响。在质量分数为1%~8%的范围内,纳米羟基锡酸锌的阻燃和抑烟效果均优于微米羟基锡酸锌。其中,添加纳米羟基锡酸锌质量分数为1%时,氧指数由27.1%提高到29.5%;添加质量分数为6%时,烟密度等级由88降到81。热重分析表明,纳米羟基锡酸锌的加入使软质PVC的残炭量在400℃以后均高于微米羟基锡酸锌,550℃时比微米羟基锡酸锌提高了4.3%,比空白PVC提高了6.4%。扫描电镜观察发现,添加纳米羟基锡酸锌的PVC燃烧残渣明显呈膨胀状态,结构最密实,起到了较好的隔氧、隔热及抑制可燃性气体逸出的作用。对试样的部分力学性能测试结果表明,添加纳米羟基锡酸锌的PVC试样的拉伸强度和断裂伸长率也有所改善,添加量在质量分数为4%时的效果最好。     

聚氯乙烯/层状双氢氧化物纳米复合材料研究进展

聚氯乙烯(PVC)/层状双氢氧化物(LDHs)纳米复合材料相比于纯聚氯乙烯具有更好的热稳定性、力学性能、阻燃抑烟性、耐候性与耐光性等,是一种性能优异并具有广泛应用前景的新型聚合物基纳米复合材料。本文首先介绍了LDHs的化学组成和结构特点,并对其制备过程和性质特点进行了分析和探讨;然后综述了PVC/LDH纳米复合材料的制备、结构表征及性能等方面的最新研究进展,重点阐述了LDHs的表面有机化处理及其对PVC/LDH纳米复合材料制备与性能的重要作用;最后对其应用前景进行展望。     

纳米LDH对环氧树脂燃烧的抑烟作用

水滑石;阻燃;纳米LDH对环氧树脂燃烧的抑烟作用     

聚氯乙烯(PVC)的阻燃与抑烟研究进展

综述了无机阻燃剂对聚氯乙烯(PVC)阻燃和抑烟性能的影响,对阻燃剂和抑烟剂作了分类介绍。重点介绍了金属氢氧化物、锑系、硼系、锡系、红磷和含锌化合物等阻燃剂,对各体系进行了比较,指出各体系的阻燃机理、添加量、以及常用的改进方法。介绍了水滑石、沸石、蒙脱土等新型无机阻燃剂,这些阻燃剂在PVC的应用中具有潜在的优势,具有添加量少、阻燃效率高的优点。阻燃剂与抑烟剂的超细化、活性化、复合化是PVC阻燃与抑烟改性的发展方向。     

水滑石晶体长厚比及晶粒尺寸控制方法研究

层状双金属氢氧化物（LayeredDoubleHydrox－ides，简称LDH）是一类重要的无机晶体材料，因其具有层状结构以及层板元素的可调控性和层间阴离子的可交换性，在催化、离子交换、吸附、医药犤１～８犦等方面具有广泛的用途，已受到人们越来越广泛的关注。近年来，随该类材料应用领域的不断拓展，在许多情况下要求LDH晶体具有小的粒径尺寸，以便最大限度地发挥其功能性。例如将LDH作为阻燃剂犤９犦使用，小粒径粉体可增强与聚合物基材的相容性，提高材料的阻燃、抑烟和力学性能。另一方面，因LDH具有层状结构，在复合材料中其层板能有效…     

PP/EVA/OMMT纳米复合材料及其阻燃材料的动态燃烧行为

利用锥形量热仪(CONE)在35kW/m2热辐照条件下,并结合极限氧指数(LOI)和UL-94垂直燃烧测试方法对聚丙烯(PP)/乙烯-醋酸乙烯酯共聚物(EVA)/有机蒙脱土(OMMT)纳米复合材料和加入无卤复配阻燃剂制备的PP/EVA/OMMT/氢氧化铝(ATH)/三氧化二锑(AO)纳米复合阻燃材料的热释放速率、烟释放及材料在燃烧时的质量损失行为进行了研究。结果表明,添加5%(质量分数)OMMT可以提高PP/EVA复合材料的阻燃性能,燃烧时的热释放速率、质量损失率以及烟释放量减少,且OMMT与无卤复配阻燃剂之间可产生阻燃协同作用,使纳米复合阻燃材料的阻燃性能、热稳定性和抑烟性进一步增强。     

膨胀型阻燃UPR复合材料的阻燃及抑烟性能

将叶蜡石(PYR)与膨胀型阻燃剂[IFR,聚磷酸铵(APP)/季戊四醇(PER)/三聚氰胺(Mel))复配],应用于不饱和聚酯树脂(UPR),得到膨胀型阻燃UPR复合材料。通过氧指数(LOI)、垂直燃烧(UL94)、烟密度等级(SDR)、热分析(DSC-TG)对阻燃复合材料的阻燃、抑烟及热稳定性能进行了研究。结果表明:在该膨胀型复配阻燃体系中,叶蜡石与IFR存在明显的协效作用,在mPYR∶mAPP∶mPER∶mMel=4∶2∶1∶1,复合阻燃剂的含量为40%的情况下,LOI高达36.4,阻燃级别为UL94 V-0级,SDR为62.95,满足国家对B1级电器类热固性塑料的使用要求。     

YSi_2纳米颗粒的制备及光学、电学性能研究

采用脉冲激光烧蚀高纯YSi2靶,在n型Si(100)单晶衬底上制备YSi2纳米颗粒。原子力显微镜(AFM)观察样品表面颗粒尺寸约40~50 nm。X射线光电子能谱(XPS)测试结果表明,YSi2纳米颗粒成分为Y-O-Si。室温下对样品的光致发光(PL)性能进行测试,在500 nm处有一个较大的宽峰,409 nm附近出现强度较弱的发光峰。前者与样品中Y-O-Si电荷迁移带有关,后者为衬底表面纳米尺寸SiOx复合中心离子发光。室温下,对原位制备的薄膜电学(I-V/C-V)性能进行测试,结果表明薄膜的介电常数约为13.6。     

层状复合氢氧化物的制备改性及其对热塑性硫化胶的阻燃作用

用氩载氨气泡膜限域共沉淀反应合成了层状复合氢氧化物(LDH)及其硬脂酸改性样品,与热塑性硫化胶Santoprene熔炼制成LDH/Santoprene复合材料,在EDS、XRD、IR和N2吸解表征的基础上,对LDH-Santoprene复合物的机械性能及燃烧性能进行了测试评价.结果表明所用合成方法能够实现小尺寸LDH微晶的快速合成与表面改性,微晶粒度及表面性能明显改观;改性样品对Santoprene有更好的复合效果和明显的阻燃作用.     

软模板法制备三维花状MgAl-LDH及其吸附性能

采用软模板法,以十二烷基硫酸钠(SDS)为模板剂,经水热合成制得三维花状双金属(Mg Al)氢氧化物(3D-Mg Al LDH)。通过XRD、FT-IR、SEM及TEM等表征手段,研究了原料Mg/Al物质的量之比、SDS浓度及反应时间对产物微观结构和表面形貌的影响规律,并初步探讨了3D-Mg Al LDH的形成机理。结果表明,当n_(Mg)/n_(Al)=2,SDS浓度为0.1 mol·L~(-1),水热反应时间为6 h时,可形成结晶度良好、花球形貌完整,纳米片厚度均一的三维花状LDH。在3D-Mg Al LDH的形成过程中,SDS既以阴离子形态参与LDH形成,又因其类球状胶束特性附着在已形成的LDH表面或边缘诱导LDH纳米片交叉生长形成三维花状。吸附实验表明,3D-Mg Al LDH对非离子型有机污染物具有良好的吸附作用,最大吸附量约为31 mg·g~(-1),去除率达到100%。     

Flame Retardant and Smoke Suppressant of Fe‐Organophilic Montmorillonite in Polyvinyl Chloride Nanocomposites

Two kinds of polyvinyl chloride (PVC)/organophilic montmorillonite (OMT) nanocomposites are prepared by a melt intercalation method. This study has been designed to determine if the presence of iron and zinc ions in the structure of montmorillonite (MMT) lattice can affect thermal, flame retardant and smoke suppressant properties. The information about the morphological structure of PVC/OMT nanocomposites was obtained using X-ray diffraction and transmission electron microscopy. The thermal and flame retardant properties of the nanocomposites were characterized by thermogravimetric analysis, limiting oxygen index and smoke density. The nanocomposites based on Fe-OMT exhibit better thermal, flame retardant properties and lower degradation degree than those of pure PVC. The degradation mechanism was studied by pyrolysis, gas chromatography and mass spectrometry (Py-GC-MS).     

Preparation and burning behaviors of flame retarding biodegradable poly(lactic acid) nanocomposite based on zinc aluminum layered double hydroxide

A flame retarding biodegradable polylactic acid (PLA) nanocomposite based on flame retardant composites (containing ammonium polyphosphate (APP), pentaerythritol (PER) and melamine cyanurate (MC) by controlling the weight ratio was 2:2:1) and organomodified zinc aluminum layered double hydroxide (Zn-Al-LDH) has been prepared by melt-compounding directly. The morphology and burning behaviour of nanocomposite with 2 wt% Zn-Al-LDH loadings were investigated. The extent of dispersion of LDH was quantified by wide angle X-ray scattering (WAXS) and transmission electron microscopy (TEM), illuminating the good dispersion state for ZnAl-LDH in the PLA matrix. Significant improvements in fire retardant performance were observed for the nanocomposite from microscale combustion calorimeter (MCC) and cone calorimetry (reducing both the heat release rate and the total heat released). It revealed that incorporation of FR and ZnAl-LDH was very efficient in improving the flame retardance of PLA composite.     

Synthesis of a carbon nanotubes/ZnAl‐layered double hydroxide composite as a novel flame retardant for flexible polyurethane foams

A composite consisting of carbon nanotubes and zinc aluminum‐layered double hydroxide (CNT/ZnAl‐LDH) with good solubility in liquid media was synthesized by a co‐precipitation method. The structural characterization and morphological observation demonstrated that the composite displayed a heterostructure with CNTs embedded in ZnAl‐LDH nanosheets. The influence of CNT/ZnAl‐LDH on the thermal stability and flammability performance of flexible polyurethane (PU) foams was characterized. It was established that CNT/ZnAl‐LDH could improve the thermal stability while reduce the peak heat release rate as well as the total smoke release of PU foams. The formation of a protective char with increased mechanical properties and high graphitization degree was mostly postulated for the improved flame retardancy. Copyright © 2015 John Wiley & Sons, Ltd.     

A New Nano‐Structured Flame‐Retardant Poly(ethylene terephthalate)

A modified nano‐hydrotalcite was used as inorganic flame‐retardant fillers for poly(ethylene terephthalate) (PET) polymers. A flame‐retardant compound was obtained from layered hydrotalcite (LDH) dispersed in brominated polystyrene (PBS) solution and then solvent evaporation from the dissolved PBS samples. The compound of PBS/LDH was characterized by X‐ray diffraction (XRD), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA) and was found to have high aspect ratio LDH dispersed in the PBS matrix. Flame‐retardant PET composite was prepared by melt‐compounding the flame‐retardant compound of PBS/LDH and PET. Improvement in the fire retardancy of the nano‐flame‐retardant PET composite obtained was found by measuring the oxygen index. The nanostructure of flame‐retardant PET composite was chirecterized by scanning electron microscopy (SEM) of flame‐retardant PET composite. The mechanical properties of the flame‐retardant PET nano‐composite were also characterized.     

海泡石对膨胀阻燃聚丙烯燃烧和热分解的影响

将改性后的海泡石添加到聚磷酸铵(APP)和双季戊四醇(DPER)膨胀阻燃聚丙烯(PP/IFR)体系中,采用氧指数(LOI)、热重分析(TGA)、光电子能谱(XPS)、傅里叶变换红外(FTIR)光谱、锥形量热仪(CONE)和扫描电镜(SEM)考察其对膨胀阻燃体系的催化协效作用,探讨作用机理.LOI结果表明,改性的海泡石比纳米水滑石和有机改性的蒙脱土有更好的催化协效作用.CONE数据证实,海泡石可以降低膨胀阻燃聚丙烯体系的热释放速率和总的热释放量.通过观察SEM图片发现,海泡石可以改善膨胀炭层的形貌,提高炭层的隔热隔质性能.TGA结果表明,在氮气和空气气氛下,海泡石均可以提高膨胀炭层的热稳定性,增加高温时残余物的量,其主要作用对象为APP.FTIR和XPS测试发现加热过程中海泡石可以与APP发生化学反应,形成P—O—Si键,增加了APP高温时的稳定性.     

The effect of Zn, Al layered double hydroxide on thermal decomposition of poly(vinyl chloride)

Poly(vinyl chloride)/layered double hydroxide (LDH) composite was prepared by mixing 4 wt% Zn₂Al-CO₃-LDH with PVC and fluxing at 180 °C. The thermal decomposition behaviour of the LDH + PVC composite in air and nitrogen environments was systematically investigated. We found that mixing Zn₂Al-CO₃-LDH into PVC facilitates dehydrochlorination from ca. 300 to 270 °C but reduces the reaction extent to leave more chlorine on the polyene backbones both in air and N₂. We have also found that at 400-550 °C, both in air and N₂, LDH assists the formation of char-like materials and decreases the release of volatile hydrocarbons. From 550 to 800 °C, the char-like materials are mostly retained in N₂ while they are almost completely thermo-oxidized (burned) in air. Thus, addition of Zn₂Al-CO₃-LDH to PVC does not increase the thermal stability, but does promote charring to retard the generation of flame. The influence of LDH on PVC thermal properties has been also addressed mechanically.     

Effect of different ionic layered compounds decorated with zinc hydroxystannate on flame retardancy and smoke performance of epoxy resin

ZHS@ Mg‐Al‐LDH and ZHS@α‐ZrP hybrid materials were prepared by electrostatically loading zinc hydroxystannate (ZHS) on the layered compounds (Mg‐Al‐LDH and α‐ZrP) in this work. With the addition of 2 wt% of the two hybrid materials to epoxy resin (EP), respectively, the fire hazard of EP and its composites were investigated. The limiting oxygen index (LOI) of ZHS@ Mg‐Al‐LDH/EP composite increased by 19.0% compared with pure EP, while its peak heat release rate (PHRR), total heat release rate (THR), and peak smoke release rate (SPR) decreased by 48.2%, 20.8%, and 21.6%, respectively, evidenced by the results of the LOI test and cone calorimetry test (CCT). The LOI of ZHS@α‐ZrP/EP composite increased by 20.4%, and its PHRR, THR, and SPR decreased by 47.7%, 21.4%, and 27.1%, respectively. Both hybrid materials showed prominent flame retardant and smoke suppressing properties. In addition, through the analysis of the TG‐IR and Raman spectrum of residual char, the specific mechanism of flame retardance and smoke suppression was explored.     

含改性硅微粉硅橡胶阻燃抑烟研究

为进一步提升硅橡胶(SR)的阻燃性能,利用硅烷偶联剂对硅微粉(SF)进行表面改性,以改性后的SF为阻燃剂,制备出SR样品。通过扫描电子显微镜(SEM)对改性前后SF表面形貌进行表征,通过极限氧指数(LOI)、水平垂直测试、锥形量热仪(CCT)、烟密度测试(SDT)等手段研究SR复合材料力学性能、阻燃性能、抑烟性能。研究表明:添加相同质量的SF和改性SF时,含改性SF的SR力学性能明显提升。其中,含21%(wt)改性SF/SR复合材料的力学、阻燃性能综合最佳。与纯SR相比,改性SF/SR复合材料的LOI增加了15%,热释放速率峰值降低86%,火灾增长指数降低了58%,最大烟密度降低43%。     

Synthesis and characterization of a flame retardant hyperbranched polyether

<正>A brominated hyperbranched polyether has been synthesized from cyanuric chloride and sodium salt of tetrabromobisphenol-A by an A_2+B_3 approach.The synthesized polyether was characterized by ~1H-NMR,~(13)C-NMR,UV, FTIR spectroscopy and X-ray diffraction studies,measurements of solution viscosity,molecular weight and solubility and elemental and thermogravimetric analyses.The flame retardancy of the synthesized polyether and its blends with commercially available plasticized poly(vinyl chloride)(PVC) and low density polyethylene(LDPE) was investigated by measurements of limiting oxygen index(LOI) value and thermogravimetric analysis.The properties are compared with a non-halogenated similar type of bisphenol-A based aromatic polyether after blending at different dose levels with the same base polymers.The LOI values of these blends indicated that these hyperbranched polyethers acted as flame retardant additives,and antimony trioxide had prominent synergistic effect with the bromo hyperbranched polyether for the above base polymers,and an increment of 4 to 6 units in LOI values was observed.