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石墨及其表面改性对硅橡胶导热性能的影响 总被引:3,自引:0,他引:3
用双辊混炼机将导热填料分散到聚甲基乙烯基硅氧烷中,再配以增强剂、硫化剂等,经模压硫化制得导热硅橡胶。研究了导热填料种类、石墨的表面改性和用量以及石墨与炭黑的复配对硅橡胶导热性和力学性能的影响。结果表明,在用量相同的情况下,导热填料的导热系数越高,其填充硅橡胶的导热性越好,且硅橡胶的导热系数随导热填料用量的增加而增大。石墨的表面改性改善了石墨与硅橡胶的界面相容性,使硅橡胶的力学性能和导热性都得到提高。不同粒径及颗粒形态的炭黑与石墨复合可改善硅橡胶的导热性和力学性能,导热硅橡胶的拉伸强度和扯断伸长率随复合填料中炭黑用量的增加而提高,当石墨与炭黑质量比为25/5时,硅橡胶的导热系数最高,综合性能较好。 相似文献
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脱醇型室温硫化导热硅橡胶的研究 总被引:1,自引:0,他引:1
采用氧化锌(ZnO)为导热填料,研究了填料对脱醇型室温硫化(RTV)硅橡胶力学性能、导热性能的影响.结果表明,在满足加工性能的前提下,随着填料用量的增加,硫化后硅橡胶的拉伸强度显著提高,由ZnO填充量10份时的0.55MPa增大至2.53MPa,而断裂伸长率下降,由309%下降至209%,100%定伸应力、硬度、撕裂强度均随填料填充量的增加而增加.随着导热填料ZnO用量的增加,RTV硅橡胶的热导率逐渐升高,当用量70份时,热导率达2.142W/m*K;随着温度的升高,填充70份ZnO的硅橡胶的热导率呈现出逐渐升高的趋势,在30℃时为2.29W/m*K,而在150℃时,热导率升高至5.9W/m*K. 相似文献
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在电子电力行业快速发展的趋势下,电子器件与设备的功率密度越来越大,导致工作温度不断升高,影响电子器件与设备的使用性能及寿命。高导热性能与绝缘性能的硅橡胶填料对电子电力行业的发展具有重要作用。基于此,本文提出了导热绝缘硅橡胶填料的制备方法,选用氮化硼作为导热绝缘填料,通过一系列改性、水解、混合、密炼、混炼、挤出、牵引造粒等工艺处理,经过高温硫化法,制备出导热绝缘性较高的硅橡胶填料。制备的硅橡胶填料热导率较高,粉体与基体的相容性较好,协同增强作用明显,能够有效降低设备热阻,全方位提高硅橡胶填料的导热绝缘性能,对我国工业化生产及应用具有重要意义。 相似文献
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研究了氮化硼微观结构(团聚体和片状微观结构)和用量对硅橡胶复合材料导热性能、力学性能、基体中分散形态结构的影响.结果 表明,随着氮化硼用量的增加,硅橡胶复合材料的拉伸强度和导热系数提高;当硅橡胶复合材料填料用量相同时,氮化硼团聚体比片状氮化硼的导热系数高,但拉伸强度低;当球状结构的氮化硼团聚体用量为100份时,硅橡胶复... 相似文献
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介绍了导热室温硫化硅橡胶的导热机理及导热模型,分析了室温硫化硅橡胶的导热性能及综合性能,并概述了国内外导热室温硫化硅橡胶的研究现状。指出通过填充不同粒径分布的填料或对填料进行适当的表面处理,可以制备高导热室温硫化硅橡胶。 相似文献
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The silicone rubber with good thermal conductivity and electrical insulation was obtained by taking vinyl endblocked polymethylsiloxane as basic gum and thermally conductive, but electrically insulating hybrid Al2O3 powder as fillers. The effects of the amount of Al2O3 on the thermal conductivity, coefficient of thermal expansion (CTE), heat stability, and mechanical properties of the silicone rubber were investigated, and it was found that the thermal conductivity and heat stability increased, but the CTE decreased with increasing Al2O3 fillers content. The silicone rubber filled with hybrid Al2O3 fillers exhibited higher thermal conductivity compared with that filled with single particle size. Furthermore, a new type of thermally conductive silicone rubber composites, possessing thermal conductivity of 0.92 W/mK, good electrical insulation, and mechanical properties, was developed using electrical glass cloth as reinforcement. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2478–2483, 2007 相似文献
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Thermally conductive silicone rubber used as elastomeric thermal pad is successfully developed with boron nitride powder as conductive filler. The effects of content and particle size of filler on the thermal conductivity and mechanical property of silicone rubber are investigated. The results indicate that the use of hybrid boron nitride with three different particle sizes at a preferable weight ratio gives silicone rubber better thermal conductivity compared with each boron nitride with single particle size at the same total filler content. Furthermore, scanning electron microscopy, differential scanning calorimeter, thermogravimetric, etc., are used to characterize the morphology, curing behavior, thermal stability, and coefficient of thermal expansion (CTE) of the silicone rubber composites. POLYM. COMPOS., 28:23–28, 2007. © 2007 Society of Plastics Engineers 相似文献
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Wenying Zhou Shuhua Qi Chunchao Tu Hongzhen Zhao Caifeng Wang Jingli Kou 《应用聚合物科学杂志》2007,104(2):1312-1318
An elastomeric thermal pad with a thermal conductivity of 1.45 W/m K, needed for the heat dissipation of microelectronics, was obtained with hybrid alumina of different particle sizes as a filler and silicone rubber (vinyl‐end‐blocked polymethylsiloxane) as the matrix. The effects of the amount, particle size, and mixing mass ratio of the filler particles on the thermal conductivity and mechanical properties of silicone rubber were investigated. The results indicated that the thermal conductivity of the rubber filled with larger particles was superior to that of the rubber filled with the smaller grain size, and the rubber incorporated with a mixture of hybrid particles at a preferable mass ratio exhibited higher thermal conductivity than the rubber for which a filler with only a single particle size was used. In addition, the surface treatment of the hybrid filler with 3‐methacryloyloxypropyltrimethoxysilane could increase the thermal conductivity of the composite rubber. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1312–1318, 2007 相似文献
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In this study, the conductive silicone rubber composites filled with nickel‐coated graphite (NCG) have been prepared, and their morphology structure, electrical conductivity, electromagnetic interference shielding efficiency (EMI SE), and mechanical properties have been investigated with reference to the NCG filler loading. The mechanical strength of NCG particle was poor that it can be easily ground into smaller particle during the mixing process if the shear force during mixing is large enough. The electrical conductivity of the composites existed an obvious threshold value with the variation of the loading amount of the conductive filler. EMI SE of the composites increases with the decrease of the volume electrical resistivity. The Payne effect can be used to characterize the intensity of the three‐dimensional conductive network structure in silicone rubber matrix, and the difference of storage modulus in the low and high shear strain has good linear correlation with the electrical conductivity. So, the electrical conductivity and EMI SE can be estimated by means of the difference of storage modulus obtained from rubber process analysis test. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
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Thermal conductivities of silicone rubber filled with ZnO in a wide volume range were measured in order to study the effect of formed conductive particle chains on thermal conductivities. With the increasing of content of ZnO particles in silicone rubber, the amount of formed conductive chains increases and the conductive chains tend linearly to increase the thermal conductivity of the composite. The experimental results obtained were also analyzed using the Nielsen and Agari models to explain the effect of ZnO filler on the formation of thermal conductive networks. Thermal conductivities of a polymer filled with high volume content of particles evidently increased with the adding of small size fillers. The scanning electron microscopy (SEM) showed that percolation threshold has been reached at 31.4 vol% ZnO filler loading, and the hybrid fillers are more densely packed than single fillers in the silicone rubber matrix. There occurs a positive temperature coefficient (PTC) phenomenon in thermal resistance in composites of silicone rubber filled with ZnO. POLYM. COMPOS., 28:125–130, 2007. © 2007 Society of Plastics Engineers 相似文献