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剥离型环氧树脂/蒙脱土纳米复合材料研究 总被引:1,自引:0,他引:1
采用阳离子交换的方法对蒙脱土进行了有机化处理,使蒙脱土由亲水性变成亲油性,并且使其层间距由原来的1.2nm扩大到2.2nm.采用X-射线衍射仪研究了有机蒙脱土在环氧树脂中的剥离行为,制备了环氧树脂/蒙脱土纳米复合材料并测试了其性能.实验结果表明,环氧树脂与有机蒙脱土的相容性好,蒙脱土在环氧树脂中完全剥离;环氧树脂/蒙脱土纳米复合材料的力学性能、热性能以及阻隔性能与纯环氧树脂固化物相比均有不同程度的提高和改善. 相似文献
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原位插层聚合法制备聚苯乙烯-蒙脱土纳米复合材料 总被引:6,自引:0,他引:6
采用双-苯基二甲基十八烷基溴化铵(TBDO)作为有机插层剂对钠基蒙脱土进行了有机化处理,该有机化的蒙脱土粒子在苯乙烯单体中很容易地均匀分散并形成稳定的胶体溶液。通过对分散有蒙脱土的苯乙烯进行自由基聚合制备了聚苯乙烯-蒙脱土纳米复合材料,X射线衍射和透射电镜研究表明形成了原位插层型和部分插层部分剥离型纳米复合材料。该纳米复合材料与同法制备的纯聚苯乙烯相比,具有更高的分子量(M^-w),较低的玻璃化转变温度(Tg)和优良的热稳定性。 相似文献
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溶液聚合制聚丙烯酰胺/蒙脱土纳米复合材料 总被引:4,自引:0,他引:4
利用溶液聚合法制备了聚丙烯酰胺/蒙脱土插层复合材料。XRD、IR等表明,聚丙烯酰胺已进入蒙脱土层间,并使之剥离。DSC表明,剥离型纳米复合材料的热稳定性提高,这是由于蒙脱土纳米片层与基体大分子链相互作用的结果。研究结果表明,复合材料调湿性能优于基体材料。 相似文献
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高度剥离型环氧树脂/蒙脱土纳米复合材料的制备与性能 总被引:2,自引:0,他引:2
以丙酮为溶剂,采用超声波分散和高速搅拌混合相结合的方法制备了高度剥离型环氧树脂/蒙脱土纳米复合材料。XRD与TEM测试结果表明,蒙脱土在环氧树脂中得到了高度剥离,大部分蒙脱土被剥离成独立片层,均匀分散于基体树脂中。对材料的力学性能、热机械性能研究表明,蒙脱土能显著提高材料的冲击强度、弹性模量,但降低了材料的拉伸强度与断裂伸长率。蒙脱土使材料的储存模量显著提高,储存模量在材料的橡胶态比在其玻璃态提高的更加明显。 相似文献
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一锅法乳液聚合制备聚苯乙烯/蒙脱土纳米复合材料 总被引:2,自引:0,他引:2
采用一锅法乳液聚合制备了聚幕乙烯/蒙脱土(PS/MMT)蚋米复合材料.一锅法即在无机蒙脱土(Na—MMT)有机化处理后,直接将乳化剂和幕乙烯单体等加入有机蒙脱土(O—MMT)悬浮液进行乳液聚合,克服了传统方法中有机蒙脱土在乳液聚合体系中不易分散的难题。XRD谱图表明,该方法成功地实现了聚苯乙烯对蒙脱土的插层.获得了良好的插层效果(蒙脱土d001面片层间距>4nm);FT—IR表明,PS大分子链已插层进入蒙脱土片层间;DSC显示,蒙脱土的加入使聚幕乙烯的玻璃化温度Tε由原来的99.7℃提高到107.1℃;TGA表明.插层复合提高了聚幕乙烯的热稳定性。此外,由XRD谱图还初步提出了一锅法乳液聚合的插层机理。 相似文献
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利用二苯基甲烷-4,4’-二异氰酸酯(MDI)与酸化的蒙脱土(MMT)表面的羟基进行反应制得了MMT-MDI;进一步利用己内酰胺(CPL)对MMT-MDI进行插层并对多余的异氰酸酯端基进行封端,制得了MMT-MDI-CPL。采用预聚体溶液插层法,利用聚酰胺酸(PAA)在二甲基乙酰胺(DMAC)溶剂中分别对MMT-MDI和MMT-MDI-CPL进行预聚体插层,制得了剥离型纳米MMT/聚酰亚胺(PI)复合材料。通过电感耦合等离子体发射光谱(ICP-OES)、FTIR、TG、XRD和SEM对改性MMT和纳米MMT/PI复合材料进行了表征。结果表明:MDI与MMT表面羟基反应而被成功接枝于MMT上;MDI对MMT的改性、CPL对MMT-MDI的插层和封端使MMT层间距得到逐步扩大;MMT/PI复合材料的XRD和断面SEM表明,MMT在PI基体中得到了充分剥离。 相似文献
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以溴化烯丙基三乙基铵改性钠基蒙脱土,采用无皂乳液聚合法制备聚苯乙烯/蒙脱土纳米复合材料。通过傅里叶变换红外(FT-IR)、X-射线衍射(XRD)和动态光散射(DLS)等手段对有机蒙脱土和复合材料的结构进行表征。结果表明:溴化烯丙基三乙基铵成功插层到蒙脱土层间,层间距由1.32nm增大到1.44nm;FT-IR和XRD测试结果表明无皂乳液聚合法制备的不同蒙脱土含量(1%~5%)的聚苯乙烯/蒙脱土纳米复合材料具有剥离型结构;DLS测试结果表明复合胶乳粒子的粒径随蒙脱土含量的增加而减小。 相似文献
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《Advanced Powder Technology》2014,25(3):926-932
Waste bleaching sodium montmorillonite clay was used to prepare carbon/clay nanocomposites and composites by calcination in a reducing atmosphere. The main purpose of this study was to determine the influence of the calcination temperature and solvent washing in the material structure and its adsorption properties. X-ray diffraction patterns detected the nanocomposite formation only in the samples calcinated at 350 °C, whose structures were also described by Fourier transform infrared spectra. SEM images showed that all the samples were composed of various agglutinated grains and the non-washed sample calcinated at 350 °C presented the highest carbon recovery as its surface was the smoothest one, as confirmed by thermogravimetry curve. As a result of this higher carbon content, its methylene blue and gasoline adsorption capacities were the highest, albeit a bit lower in comparison to activated carbon due to the hydrocarbon formation onto sample surface. Finally, BET and BJH studies showed that porosity should also be improved in order to achieve higher adsorption values. 相似文献
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Chigwada G Kandare E Wang D Majoni S Mlambo D Wilkie CA Hossenlopp JM 《Journal of nanoscience and nanotechnology》2008,8(4):1927-1936
Organically-modified montmorillonite (MMT) clays have been prepared using ammonium salts containing quinoline, pyridine, benzene, and styrenic groups. The nanocomposites were prepared by melt blending and the formation of nanocomposites was characterized using X-ray diffraction (XRD) and transmission electron microscopy (TEM). Thermal stability and flammability were evaluated by thermogravimetric analysis (TGA) and cone calorimetry measurements, respectively. The presence of modified MMT at 5% loading resulted in significant improvement in thermal stability compared to the virgin polymer. Effective activation energies for mass loss were determined via a model-free isoconversional approach from TGA data obtained under N2 and under air. The additives served to raise the activation energy, with a more significant impact observed under pyrolysis conditions. The onset temperature of degradation and temperature of maximum decomposition rate are increased, while the peak heat release rate and mass loss rates are significantly reduced in the presence of three of the modified clays. No reduction in the total heat released is observed. 相似文献
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《Materials Chemistry and Physics》2007,101(2-3):291-296
Magnetite (Fe3O4) nanoparticles were prepared by in situ precipitation and oxidation of ferrous ions in the presence of ω-functionalized polystyrenes having carboxylate, sulfonate, thiol, and thiolated groups. Based on the results for the orthogonal experimental design, both the ratio of the concentration of iron precursor to polymer and the reaction temperature were the major factors controlling the particle size and its shape morphology. By adjusting the reaction conditions, the iron oxide particle size can be effectively controlled in the range between 2 and 20 nm. The magnetite-based polymer composite was characterized by UV–vis spectroscopy, thermogravimetric analysis, transmission electron microscopy, and X-ray diffraction. Magnetization measurements revealed that the nanocomposite materials exhibit superparamagnetic behavior at room temperature. 相似文献
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聚合物/蒙脱土纳米复合材料的制备与结晶性能 总被引:14,自引:1,他引:14
本文综述了制备聚合物 /蒙脱土纳米复合材料的插层方法 ,并对有代表性的结晶性聚合物 /蒙脱土纳米复合材料的结晶性能进行了讨论。蒙脱土的加入对聚合物的结晶有两种作用 ,一方面是对聚合物有异相成核的作用 ,可以提高聚合物的结晶温度和结晶速率 ,降低结晶活化能 ;另一方面是对聚合物结晶生长有阻碍作用 ,导致结晶速率下降 ,结晶活化能提高 相似文献
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A combination of starch and clay for the preparation of nanocomposite materials is proposed. In this work, starch was plasticized by pequi (Caryocar brasiliense) oil, and thermoplastic starch (TPS)/montmorillonite (MMT) nanocomposites were analyzed by X-ray diffraction (XRD), thermogravimetry (TG), thermomechanical analyses (TMA) and scanning electron microscopy (SEM). Exfoliated and intercalated nanocomposites were found to be dependent on MMT content. Exfoliation is the predominant mechanism of clay dispersion for low filler loading. Increase of the clay loading (>5 wt.%) causes intercalation. The introduction of low content (?5 wt.%) of MMT improves the thermal stability and the stiffness of the materials. There is a limit content of clay that can be added to improve the thermal and thermomechanical properties of the composites. Beyond that value the composite presents properties below the original polymer. 相似文献
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Intercalated methacryloylpropyltrimethoxysilane (VMMS)-grafted polyethylene (PE-g-VMMS) /organo-montmorillonite (OMT) nanocomposite was prepared by melt intercalation. Its morphology and thermal characteristics were carried out by X-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analyses (TGA) and dynamic Fourier transfer infrared (FTIR) spectroscopy. The intercalated tactoids of silicate layers within PE-g-VMMS have been verified by XRD and TEM image. TGA profiles of the nanocomposite show that the presence of the silicates exerts a significant stabilization effect on thermal-oxidative degradation process from 250 to 375°C, but less effect above 375°C. Dynamic FTIR spectra reveal that this nanocomposite has a slower thermal-oxidative degradation rate of main chains than that of pure PE-g-VMMS, but a faster rate of the pendant VMMS grafts. 相似文献