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综述了以聚合物为基体的碳纳米管复合材料导热模型,分析了复合材料热传导体系中碳纳米管(CNTs)填料的作用机制,归纳了混合规则导热模型、均质模型、有效介质模型、非均质模型和随机分散模型等,并总结了导热模型常用的数值计算方法。这些模型丰富了导热理论,可以对复合材料导热系数进行初步预测,但在数值上都存在近似或者简化处理,对碳纳米管/聚合物复合材料预测广谱性较差。未来需要对分子尺寸和界面热阻等影响导热系数的关键因素深入探究,改善数值和表征分析方法,以期为碳纳米管/聚合物复合材料的导热性能的研究和设计提供参考,为其他复合材料导热性能的研究提供借鉴。 相似文献
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碳纳米管(CNTs)由于优异的轴向导热性能,是目前制备高热导率聚合物基复合材料的一类重要填料。本文综述了近年来CNTs增强聚合物复合材料的研究进展,探讨了CNTs/聚合物复合材料的导热机理以及CNTs用量、尺寸及结构、表面改性、混杂CNTs粒子和聚合物基体结构等因素对CNTs/聚合物复合材料热导率的影响。同CNTs/聚合物的电导率相比,热导率远低于预期值,归因于CNTs/树脂界面间的声子频率失配现象导致了声子在界面的散射及很高的界面接触热阻,从而降低了体系热导率。分析和总结了改善体系热导率的方法和措施,采用特殊工艺使CNTs在基体内形成特殊的隔离结构或者取向结构是CNTs/聚合物导热复合材料的未来研究及发展方向。 相似文献
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孔娇月;陈立新;蔡聿峰 《中国塑料》2011,25(3):7-12
在介绍金属材料、无机非金属材料以及高分子材料导热机理的基础上,介绍了导热填料填充高分子复合材料的导热网链机理和热弹性组合机理2种导热机理,该理论可以解释导热高分子复合材料导热过程中不同的现象和规律;归纳了适用于粒子、纤维等填充的聚合物基复合材料的各种导热模型;讨论了树脂基体、导热填料和温度对于高分子复合材料热导率的影响... 相似文献
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基于最小热阻力法则和比等效导热系数法则,建立一新的颗粒填充聚合物复合材料的导热模型并导出等效导热系数公式。应用该公式估算了酚醛树脂/铝粉和酚醛树脂/石墨复合材料的等效导热系数,并与试验测量数据比较。结果表明,导热系数的理论预测值和试验数据相当接近。 相似文献
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导热高分子复合材料的研究进展 总被引:3,自引:0,他引:3
概述了国内外导热高分子复合材料的研制和应用情况,并从理论上介绍了导热高分子复合材料的结构特征、导热机理,以及导热理论模型。在此基础上探讨了优化导热高分子复合材料综合性能的方法。 相似文献
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分别用氧化铝(Al_2O_3)单组分和Al_2O_3/碳纳米管(CNTs)双组分为填料,制备了导热乙烯基聚二甲基硅氧烷(PDMS),通过动态流变测试仪研究了体系的导热网络结构,并采用Hashin-Shtrikman边界模型分析了CNTs在导热网络结构中的桥架作用。结果表明,CNTs的加入增强了PDMS体系中Al_2O_3填料的网络效应,完善了导热网络结构,且微量的CNTs搭在分散的Al_2O_3上形成连续分布的导热通道,起到桥架的作用,使体系的导热系数有较明显的提高。 相似文献
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填充型导热高分子复合材料研究进展 总被引:4,自引:0,他引:4
综述了国内外导热绝缘填料、导热非绝缘填料和混杂填料填充的导热高分子材料的研究进展.简要地介绍了导热高分子材料的导热机理.分析了导热高分子复合材料目前存在的一些问题,并对其研究方向给出了一些建议. 相似文献
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采用不同品种、粒径的导热填料和基体树脂,以熔融共混方法制备聚合物/填料体系导热功能复合材料。研究了复合材料热导率λ和体积电阻率ρv随不同填料、粒径等因素的变化规律及其内在原因。不同填充体系的热导率均随填料粒径的减小而降低,而电导率则相反;复合体系热导率随填料含量的增加始终呈逐步上升趋势,未表现出电导率那样的急剧变化。研究表明:复合体系热导率和电导率变化的差异主要是由于二者具有不同的传导机理;复合材料热导率的变化规律可以用热弹性复合增强机制进行合理解释。 相似文献
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Mario Martin-Gallego Raquel Verdejo Mohamed Khayet Jose Maria Ortiz de Zarate Mohamed Essalhi Miguel Angel Lopez-Manchado 《Nanoscale research letters》2011,6(1):610
We employed an easy and direct method to measure the thermal conductivity of epoxy in the liquid (nanofluid) and solid (nanocomposite) states using both rodlike and platelet-like carbon-based nanostructures. Comparing the experimental results with the theoretical model, an anomalous enhancement was obtained with multiwall carbon nanotubes, probably due to their layered structure and lowest surface resistance. Puzzling results for functionalized graphene sheet nanocomposites suggest that phonon coupling of the vibrational modes of the graphene and of the polymeric matrix plays a dominant role on the thermal conductivities of the liquid and solid states.PACS: 74.25.fc; 81.05.Qk; 81.07.Pr. 相似文献
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Chih‐Chun Teng Chen‐Chi M. Ma Shin‐Yi Yang Kuo‐Chan Chiou Tzong‐Ming Lee Chin‐Lung Chiang 《应用聚合物科学杂志》2012,123(2):888-896
The well dispersed multiwalled carbon nanotube (MWCNT)/epoxy composites were prepared by functionalization of the MWCNT surfaces with glycidyl methacrylate (GMA). The morphology and thermal properties of the epoxy nanocomposites were investigated and compared with the surface characteristics of MWCNTs. GMA‐grafted MWCNTs improved the dispersion and interfacial adhesion in epoxy resin, and enhanced the network structure. The storage modulus of 3 phr GMA‐MWCNTs/epoxy composites at 50°C increased from 0.32 GPa to 2.87 GPa (enhanced by 799%) and the increased tanδ from 50.5°C to 61.7°C (increased by 11.2°C) comparing with neat epoxy resin, respectively. Furthermore, the thermal conductivity of 3 phr GMA‐MWCNTs/epoxy composite is increased by 183%, from 0.2042 W/mK (neat epoxy) to 0.5781 W/mK. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 相似文献
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In this study, we prepared nanocomposites comprising multiwalled carbon nanotubes (MWCNTs) and polybenzoxazine (PBZ). The MWCNTs were purified through microwave digestion to remove most of the amorphous carbon and metal impurities. After purification, MWCNTs were treated with H2SO4/HNO3 (3 : 1) to introduce hydroxyl and carboxyl groups onto their surfaces. Raman spectroscopy revealed the percentage of nanotube content improved after prolonged microwave treatment, as evidenced by the decrease in the ratio of the D (1328 cm?1) and G (1583 cm?1) bands. For the untreated MWCNTs, the ID/IG ratio was 0.56. After microwave treatment for 40 min, the value decreased to 0.29, indicating that the percentage of nanotube content improved. Dynamic mechanical analyses (DMAs) revealed that the storage moduli and the Tgs of the MWCNTs/PBZ nanocomposites were higher than that of the pristine PBZ. This is due to the nanometer‐scale MWCNTs restricting the motion of the macromolecular chains in the nanocomposites. Transmission electron microscopy (TEM) image revealed that the MWCNTs were well dispersed within the PBZ matrix on the nanoscale when the MWCNT content was less than 2.0 phr. The coefficient of thermal expansion (CTE) of the nanocomposites decreased on increasing the MWCNTs content. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 相似文献
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随着电子产品的小型化、集成化和功能化发展,功率密度及热流密度急剧上升,器件内巨大的散热和温压压力使电子设备的寿命和可靠性受到影响,因此对器件在运行过程中如何有效散热提出了更为苛刻的要求。开发及使用高性能导热基复合材料(热界面材料,TIM)降低接触热阻是解决电子设备散热问题的有效途径之一,热界面材料创新与优化备受关注。本文从基本的导热机理出发,阐述聚合物基热界面材料结构及导热强化方面最新进展,讨论导热填料和聚合物基体对复合材料性能的影响。重点对微纳结构的导热强化(协同)作用、构筑3D高导热微结构、导热填料和基质间的界面微结构和导热互穿网络结构等进行讨论,为设计高性能导热结构、制备开发新型高性能TIM提供参考。 相似文献
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苯乙烯丙烯酸树脂为墨粉主要组分,其导热性能提升可显著提高墨粉导热性能,进而延长打印、复印机使用寿命。通过在苯乙烯丙烯酸树脂中添加碳纳米管、石墨烯高导热单一或复合填料,在苯乙烯丙烯酸树脂构建连通导热网络以提高其导热性能。当苯乙烯丙烯酸树脂中添加0.75wt%多壁碳纳米管时,其导热系数可提高至0.1644 W/(m?K),增幅为31.31%;添加1.0wt%羧基改性多壁碳纳米管时,苯乙烯丙烯酸树脂导热系数可提高至0.1751 W/(m?K),增幅为39.86%;在苯乙烯丙烯酸树脂添加多壁羧基改性碳纳米管和石墨烯混合填料时,苯乙烯丙烯酸树脂导热系数可提升至0.2093 W/(m?K),增幅达到67.17%。表明碳纳米管和石墨烯混合填料可在苯乙烯丙烯酸树脂中形成有效的导热网络,从而显著提高苯乙烯丙烯酸树脂导热性能。 相似文献
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Adding conductive carbon fillers to electrically insulating thermoplastic polymers increases the resulting composite's electrical conductivity, which would enable them to be used in electrostatic dissipative and semiconductive applications. In this study, varying amounts of carbon black (CB: 2 to 10 wt %), multiwalled carbon nanotubes (CNT: 0.5 to 8 wt %), or exfoliated graphite nanoplatelets (GNP: 2 to 15 wt %) were added to polycarbonate (PC) and the resulting composites were tested for electrical conductivity (EC = 1/electrical resistivity). The percolation threshold was ~ 1.2 vol % CNT, ~ 2.4 vol % CB, and ~ 4.6 vol % GNP. In addition, three EC models (Mamunya, additive, and general effective media) were developed for the CB/PC, CNT/PC, and GNP/PC composites. The general effective media (GEM) model showed the best agreement with the experimental results over the entire range of filler concentrations (above and below the percolation threshold) for all three composite systems. In addition, the GEM model can be easily adapted for composites containing combinations of different conductive fillers. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 相似文献
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Effect of crosslink density on thermal conductivity of epoxy/carbon nanotube nanocomposites 下载免费PDF全文
The effect of the polymeric crosslink density on the thermal conductivity of an epoxy nanocomposite was investigated by adding two different diamine‐functionalized multiwalled carbon nanotubes (diamine‐MWNTs) to the epoxy resin as co‐curing agents and conducting fillers. Tetramethylenediamine (TMDA)‐MWNTs resulted in an epoxy nanocomposite with a higher crosslink density than octamethylenediamine (OMDA)‐MWNTs. Interestingly, epoxy/TMDA‐MWNT nanocomposites under 1.5 wt % nanotube concentration, showed a higher thermal conductivity than an epoxy/OMDA‐MWNT nanocomposite with the same concentration of nanotubes. In contrast, for higher diamine‐MWNT concentrations (over 2.0 wt %), the thermal conductivity of the epoxy/OMDA‐MWNT nanocomposite was higher than that with TMDA‐MWNTs. We observed that for low MWNT concentrations, where a percolating network was not formed, a high crosslink density enhanced the thermal conductivity via phonon transport. However, for high MWNT concentrations, a high crosslink density hinders the formation of a percolating network and lowers the thermal conductivity. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44253. 相似文献