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本文研究了以石墨、银粉为导电填料的环氧树脂/咪唑类导电粘合剂;通过固化剂改性,以银粉为主要导电填料,石墨为辅助导电填料,制得一种性能优良、涂覆性好的导电粘合剂。 相似文献
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半导电屏蔽层是高压交直流电缆的重要组成部分,起到消除电缆绝缘与导体/金属屏蔽界面缺陷、均匀电场的作用。本文阐述了半导电屏蔽复合材料的导电机理及正、负温度电阻系数(PTC/NTC)效应;分析半导电屏蔽层表面光滑度的影响因素,提出基于白光干涉三维表面轮廓扫描的表面光滑度精确评估方法;综述了聚合物基体和导电填料对半导电屏蔽复合材料体积电阻率及PTC效应的影响,表明高长径比填料与炭黑复配填充可有效改善其高温下的半导电特性。针对高压直流电缆,分析半导电屏蔽层界面能带结构对空间电荷注入和积聚的影响机理。最后,剖析现有国产半导电屏蔽材料的局限性,展望了热塑性环保型高压直流电缆用半导电屏蔽复合材料的发展方向。 相似文献
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导电硅橡胶弹性体的性能与影响因素 总被引:7,自引:3,他引:4
介绍了在一定用途的绝缘聚合物上加适量导电填料(导电炭黑)生产导电塑料与导电硅橡胶弹体等导电聚合材料的方法。聚合材料的导电率随填料量的增加先缓慢上升,当填料量达到渗透极限后则以指数曲线快速上升。这种材料的机、电性能取决于原料和加工方法,与温度、拉伸、压力、电场状况等多种因素相关。此材料产品可应用于高电压及电子技术、医疗技术等领域。 相似文献
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本文研究了以石墨、银粉为导电填料的环氧树脂/咪唑类导电粘合剂;通过固化剂改性,以银粉为主要导电填料,石墨为辅助导电填料,制得一种性能优良、涂覆性好的导电粘合剂。 相似文献
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CuCr触头材料导电特性的三维仿真 总被引:5,自引:2,他引:3
从CuCr合金导电特性的唯象过程出发,建立了计算触头材料导电特性的三维单元网络模型。应用此模型分别计算了组份含量、孔隙等参数对材料电导率的影响,并与测量值进行了比较。结果表明了这种模型的有效性。 相似文献
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Conducting polymer composites become increasingly important for technical applications. In this article, the resulting electrical properties of such materials are illustrated by a variety of experimental examples. It is shown that the combined mechanical, thermal and electrical interaction between the filler particles via their electrical contacts and the surrounding polymer host matrix are responsible for the properties of the composite material. A short review is given of the theoretical background for the understanding of the electrical transport in such materials. The arrangement of the filler particles and the resulting conductivity can be described either by percolation or by effective medium theories. It can also be related to different types of charge carrier transport processes depending on the internal composite structure. Special emphasis is given to the microstructure of the filler particles such as size, hardness, shape and their electrical and thermal conductivities. A detailed analysis of the physics of the contact spots and the temperature development during current flow at the contact is given. It is shown that the polymer matrix has a strong influence on the electrical conductivity due to its elastic properties and the response to external thermal and mechanical stimulation. Strong changes in the electrical conductivity of conducting polymer composites can be realized either by thermal stimuli, leading to a positive and negative temperature coefficient in resistivity, or by applying mechanical stress. By using nonlinear fillers an additional degree of functionality can be achieved with conducting polymers. 相似文献
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Robertson J. Varlow B.R. 《Dielectrics and Electrical Insulation, IEEE Transactions on》2005,12(4):779-790
The use of ferroelectric fillers in polymers can allow the formulation of a composite material which possesses enhanced AC currents at elevated electrical field strengths. This non-linear characteristic can be utilised as a stress relieving mechanism in applications with non-uniform electric fields. The enhanced characteristics are achieved through electrical field dependent permittivity mechanisms, which are occurring within the composite material. These stress relieving materials have distinct advantages over previous stress relieving polymer composites, using conductive or semi-conductive fillers, however, stress relief is only realisable under AC fields. The ferroelectric material used in these investigations is barium titanate, which has been used as a filler in an acrylic base resin system. The experimental results show how both the AC and DC conductivities are influenced by the electrical field strength, at a variety of filler concentrations. The research has also looked into how the AC and DC characteristics change as the degree of cure of the resin system is increased and how the particle size of the barium titanate influences the behaviour of the material. 相似文献
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随着交联聚乙烯(XLPE)绝缘直流电缆电压等级的提高,对半导电屏蔽料的质量及可靠性的要求也越来越高。选用了2种国外高电压等级用直流半导电屏蔽料、一种国产较为优秀的半导电屏蔽料和国内XLPE直流电缆绝缘料作为试验材料,测试了3种屏蔽料的热、电性能,屏蔽与绝缘的复合性能,研究了3种屏蔽料对XLPE绝缘空间电荷的影响。通过对试验结果的综合分析,提出了炭黑填充量、炭黑粒径和基体树脂以及界面结合情况是影响半导电屏蔽料体积电阻率和空间电荷注入的关键因素。 相似文献
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Yayoi Abe Paramatma Chandra Mathur Pramod Kumar Bhatnagar Kazuya Tada Mitsuyoshi Onoda 《Electrical Engineering in Japan》2011,174(4):1-8
The electrochemical polymerization of pyrrole on an ITO (indium‐tin oxide)‐coated glass electrode with an insulating film of poly(vinyl alcohol), PVA, produces a flexible composite polymer film with electrical, optical, and electrochemical properties very similar to polypyrrole (PPy). The rate of electrochemical polymerization depends on the diffusion of the electrolyte across the PVA film to the ITO electrode. In particular, hydrophilic solvents easily penetrate into the PVA film. By applying this new process, we demonstrate a unique method of forming electrically conductive patterns in PVA film. It will be possible to develop electrodes for electrical stimulation of the nervous system using a conducting polymer, PPy. By a similar technique we have fabricated poly(3,4‐ethylenedioxythiophene), PEDOT/PVA, composite films and have investigated their electrochemical basic properties. © 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 174(4): 1–8, 2011; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21055 相似文献
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炭黑填充型硅橡胶复合材料的制备及其性能研究 总被引:1,自引:0,他引:1
以硅橡胶为基体,T60导电炭黑为填料,制备了填充型硅橡胶复合材料。研究了炭黑填充量、硫化剂用量以及硫化时间对橡胶物理性能和导电性能的影响。结果表明:炭黑填充量、硫化剂用量以及硫化时间均会对橡胶的物理性能和导电性能产生影响。其中,炭黑填充量对橡胶的导电性能影响最为显著。当炭黑用量为20份,硫化剂用量为7份,硫化时间为11 min时,所得橡胶的物理和导电性能最佳,拉伸强度为5.67 MPa,扯断伸长率为133.1%,撕裂强度为16.9 kN/m,邵尔A硬度为81,体积电阻率为165Ω.cm。 相似文献
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Yamanaka S. Fukuda T. Sawa G. Ieda M. Ito M. Seguchi T. 《Dielectrics and Electrical Insulation, IEEE Transactions on》1995,2(1):54-61
The effect of filler concentration on the dielectric properties in the ultralow-frequency region and on the electrical conductivity was studied for ethylene propylene rubber. First, we investigated the relation between the electrical conductivity and filler concentration: as the volume fraction of fillers qa increased, the conductivity decreased in the low filler concentration region but increased abruptly in the high filler concentration region. The decrease and increase in conductivity can be explained with the action of carrier traps at the interface between EPR and fillers and with the formation of highly conductive paths of filler across the sample, respectively. Secondly, we studied the dielectric properties in the ultralow-frequency region which was obtained from the discharge current. As qa increased, the relaxation time decreased in the low filler concentration region and then rose in the high filler concentration region. The polarization in the high filler concentration region can be explained by two-layer interfacial polarization between filler and rubber 相似文献
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In this paper, a wide variety of high dielectric constant (k) composite materials which have been developed and evaluated for embedded capacitor application are reviewed. Current research efforts toward achieving high dielectric performance including highk and low dielectric loss for polymer composites are presented. New insights into the effect of unique properties of the nanoparticle filler, filler modification and the dispersion between filler and polymer matrix on the dielectric properties of the nanocomposites are discussed in details. 相似文献
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This paper is presented as an example of a parametric approach that may be applied to engineering the radio and microwave properties of composite materials in the context of providing electromagnetic shielding capability. In this case, the composites are formed by a conductive filler component embedded within an insulating material. The effective electromagnetic (permittivity) properties of the composite are modeled under the quasistatic approximation using the McLachlan general effective medium model, which enables the impact of the percolation (insulator-conductor) transition to be explored. Composites within the transition region exhibit a power-law nature to their effective material properties. The power-law exponents may take a range of values above a limiting value set by the dimensionality of the filler particle network within the composite and with the assumption of a perfectly random distribution of filler particles. In practice, the values of the power-law exponents depend on the chemical interactions between the constituents, the processing conditions and the nature of the inter-particle charge transport. The paper demonstrates the implications of different values of power-law exponent in the context of the trade-off between shielding effectiveness and composite thickness. 相似文献