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不同有机化蒙脱土对聚丙烯/蒙脱土纳米复合材料结构和性能的影响 总被引:4,自引:0,他引:4
采用不同的有机改性剂制备了三种含羟基极性基团、环氧基和不含极性基团的有机化蒙脱土, 并与混有少量马来酸酐接枝聚丙烯的聚丙烯基体进行复合, 制备了聚丙烯粘土纳米复合材料. 采用X射线衍射仪、透射电子显微镜、热分析仪、示差扫描热分析仪和力学测试仪对样品进行结构表征和力学性能测试. 探讨和比较了不同有机化蒙脱土对聚丙烯/蒙脱土纳米复合材料结构和性能的影响. 结果表明, 携带极性基团的有机改性剂和马来酸酐接枝聚丙烯的强烈相互作用有利于有机化蒙脱土在复合材料中的插层、剥离和稳定性, 由此形成的聚丙烯粘土纳米复合材料具有更高的结晶度, 其力学性能的提高也更为显著. 相似文献
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Fe-Al-Mg-MMH/钠质蒙脱土分散体系触变性研究 总被引:3,自引:0,他引:3
研究了Fe-Al-Mg型混合金属氢氧化物(简称MMH)/钠质蒙脱土(简称MT)分散体系的触变性,发现在不同MMH/MT质量比(R)条件下,分散体系可分别呈现正触变性和负触变性.在所研究的R范围(0~0.091)内,随R增大,体系的触变性发生正触变性-复合触变性-负触变性的转化.考察了高速剪切分散后,测定粘度变化前的静置时间(ts)和测定粘度时的剪切速率(DL)对触变性的影响.探讨了各种触变性产生的原因,提出了“分散粒子-空间连续网络结构-密实聚集体”和“分散粒子-密实聚集体-密实聚集体簇”机理,较合理地解释了观察到的复合触变现象. 相似文献
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高密度聚乙烯/蒙脱土纳米复合材料膨胀阻燃体系的性能 总被引:1,自引:0,他引:1
使用以乙烯/醋酸乙烯共聚物(EVA)为相容剂的高密度聚乙烯/蒙脱土(HDPE/OMT)纳米复合材料作为基体,制备了含不同成炭剂的聚磷酸铵(APP)膨胀阻燃体系,对其阻燃性能进行了比较和研究,并分析了蒙脱土与膨胀阻燃剂协效作用的机理。热重分析(TGA)、垂直燃烧(UL-94)、极限氧指数(LOI)、锥形量热计结果表明:APP/季戊四醇(PER)体系熔融过程较短可形成蒙脱土增强炭层;PER/PA/OMT体系中较高的有机物含量有利于蒙脱土迁移和堆积。 相似文献
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悬浮缩聚法制备酚醛树脂/蒙脱土纳米复合材料 总被引:13,自引:0,他引:13
采用悬浮缩聚方法在酸性催化剂作用下制备了酚醛树脂/蒙脱土纳米复合材料。以三种不同的蒙脱土:天然土、带有脂肪链季铵盐修饰蒙脱土和带有苯环基团的插层剂修饰的蒙脱土为原料制备了纳米复合材料,并考察了不同插层剂对纳米复合材料形貌的影响,发现带有苯环的插层剂修饰的蒙脱土与酚醛树脂的相容性能更好;研究了固化过程对纳米复合材料形貌的影响,XRD和TEM的结构表明固化过程可以促进带有脂肪链季铵盐修饰的蒙脱土进一步剥离,对其他两类的影响不大;此外还用TGA研究了纳米复合材料的热性能。 相似文献
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Klaus Fischer Karsten Krasselt Ingeborg Schmidt Derek Weightman 《Macromolecular Symposia》2005,223(1):109-120
The distribution of substituents of cellulose xanthogenate and carboxymethyl cellulose along the cellulose chains and therefore in relation to the molecular mass can be measured using size exclusion chromatography including a multi angle laser light scattering and mass detection for determining the molecular mass of the derivative assisted by an UV- detection for determining the xanthate groups and carboxymethyl groups after derivatisation, respectively. The results investigating cellulose xanthogenate show that the temperature used in dissolving xanthogenate and in ripening viscose influences the distribution of xanthate groups in a different way; but all steps processing viscose are connected with a loss in the degree of substitution in ripening the distribution of substitution additionally becomes more even. The investigated carboxymethyl cellulose revealed different distribution of carboxylic groups in dependence on the viscosity of the CMC. 相似文献
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基于羧甲基纤维素钠制备氮掺杂多孔炭及其电容性能研究 总被引:3,自引:0,他引:3
以羧甲基纤维素钠(NaCMC)为碳源, 利用直接炭化工艺(无需进一步活化)制备多孔炭材料; 然后, 以CO(NH2)2为氮源, 形成了氮掺杂多孔炭材料. 氮的存在形式包括吡啶N、石墨N和吡咯N. 实验结果表明, 羧甲基纤维素钠与CO(NH2)2之间的配比可以有效控制氮存在形式、含量、样品的比表面积及孔的结构等. 样品的电化学性能测试表明, 氮掺杂后多孔炭材料的超电容性能得到了显著提升. 以carbon-N-1:20为例, 其比表面积可达858 m2·g-1, 远高于未经氮掺杂carbon-blank 的463 m2·g-1, 其质量比电容则由94.0 F·g-1提高到了156.7F·g-1. 相似文献
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Wilson Pires Flauzino Neto Hudson Alves Silvério Júlia Graciele Vieira Héden da Costa e Silva Alves Daniel Pasquini Rosana Maria Nascimento de Assunção Noélio Oliveira Dantas 《Macromolecular Symposia》2012,319(1):93-98
Summary: Cellulose nanocrystals (CNC) were extracted from Kraft pulp of Eucalyptus urograndis. The CNC were isolated by acid hydrolysis with H2SO4 64% (w/w) solution, for 20 minutes at 45 °C. The morphology and crystallinity of the CNC were investigated by atomic force microscopy (AFM) and X-ray diffraction (XRD), respectively. The AFM image supports the evidence for the development of crystals of cellulose in nanometric scale. These nanoparticles were used as reinforcement material in carboxymethyl cellulose (CMC) matrix. Nanocomposites films were prepared by casting. The nanocomposites were characterized by thermal (TGA) and mechanical (DMA) analyses. A large reinforcing effect of the filler was observed. The tensile strength of nanocomposites was significantly improved by 107%, the elongation at break decreased by 48% and the thermal resistance increased slightly. The improvements in thermo-mechanical properties suggest a close association between filler and matrix. 相似文献
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以离子型纤维素醚羧甲基纤维素(CMC)的水溶液为反应介质,制备[Zn4CO3(OH)6]CMC水凝胶,洗涤、干燥后经不同温度煅烧前驱物得到ZnO纳米粒子。通过XRD、SEM、TEM、TG-DSC及FT-IR等测试技术对产物的组成、粒径及形态进行表征,研究了CMC对前驱物及ZnO形态和尺寸的影响。结果表明,由于CMC加入对煅烧前驱物产生的空间位阻作用,所制得纳米ZnO粒子粒度分布均匀、分散性好、不易团聚、粒子的平均粒径<20 nm。利用UV-V is测试了纳米ZnO的光吸收性能,所得的纳米ZnO在200~400 nm具有较强的吸收性。 相似文献
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The effect of sodium carboxymethyl cellulose (Na-CMC) on the corrosion behavior of mild steel in 1.0 mol·L−1 HCl solution has been investigated by using weight loss (WL) measurement, potentiodynamic polarization, linear polarization resistance (LPR), and electrochemical impedance spectroscopy (EIS) methods. These results showed that the inhibition efficiency of Na-CMC increased with increasing the inhibitor concentration. Potentiodynamic polarization studies revealed that the Na-CMC was a mixed type inhibitor in 1.0 mol·L−1 HCl. The adsorption of the inhibitor on mild steel surface has been found to obey the Langmuir isotherm. The effect of temperature on the corrosion behavior of mild steel in 1.0 mol·L−1 HCl with addition of 0.04% of Na-CMC has been studied in the temperature range of 298–328 K. The associated apparent activation energy (E*a) of corrosion reaction has been determined. Scanning electron microscopy (SEM) has been applied to investigate the surface morphology of mild steel in the absence and presence of the inhibitor molecules. 相似文献
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The effect of sodium carboxymethyl cellulose (Na-CMC) on the corrosion behavior of mild steel in 1.0 mol·L-1 HCl solution has been investigated by using weight loss (WL) measurement, potentiodynamic polarization, linear polarization resistance (LPR), and electrochemical impedance spectroscopy (EIS) methods. These results showed that the inhibition efficiency of Na-CMC increased with increasing the inhibitor concentration. Potentiodynamic polarization studies revealed that the Na-CMC was a mixed type inhibitor in 1.0 mol·L-1 HCl. The adsorption of the inhibitor on mild steel surface has been found to obey the Langmuir isotherm. The effect of temperature on the corrosion behavior of mild steel in 1.0 mol·L-1 HCl with addition of 0.04% of Na-CMC has been studied in the temperature range of 298-328 K. The associated apparent activation energy (E*a ) of corrosion reaction has been determined. Scanning electron microscopy (SEM) has been applied to investigate the surface morphology of mild steel in the absence and presence of the inhibitor molecules. 相似文献
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海藻酸钠/羧甲基淀粉共混膜 总被引:6,自引:0,他引:6
用溶液共混法成功制备出海藻酸钠/羧甲基淀粉共混膜,IR、XRD、SEM结构表征以及力学性能、吸水性和水蒸汽透过率测定结果表明:共混膜中海藻酸钠和羧甲基淀粉间存在强烈的分子间氢键等相互作用及良好的相容性;随羧甲基淀粉含量的增加,共混膜的吸水率显著降低;当羧甲基淀粉含量(wCMS)=0.20时,共混膜的抗张强度和断裂伸长率分别为53.1MPa和5.3%,比海藻酸钠膜分别提高了97.4%和60.6%,水蒸汽透过率达最小值,是一种具有潜在应用前景的可食性包装膜材料。 相似文献
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A facile microwave method (MW) is described that accomplishes alignment and decoration of noble metals on carbon nanotubes (CNT) wrapped with carboxymethyl cellulose (CMC). Carbon nanotubes such as single‐ and multi‐walled, and Buckminsterfullerene (C‐60) are well dispersed using the sodium salt of CMC under sonication. Addition of respective noble metal salts then generates noble metal‐decorated CNT composites at room temperature. However, aligned nanocomposites of CNTs could only be generated by exposing the above nanocomposites to MW irradiation. The CNT composites are characterized using scanning electron microscopy, energy dispersive X‐ray analysis, X‐ray mapping, transmission electron microscopy, and UV‐visible spectroscopy. The general preparative procedure is versatile and provides a simple route to manufacturing useful metal‐coated CNT nanocomposites.