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利用导热仪和差示扫描量热仪,研究了绝缘型导热填料氧化镁(MgO)的粒径和用量对聚酰胺6(PA6)导热性能和结晶行为的影响。结果表明:PA6的热导率随MgO用量的增加而提高;相同用量时,MgO的粒径越大,其对PA6热导率的提升越大;不同粒径的MgO掺杂使用时,PA6/MgO导热材料的热导率随大粒径MgO比例的增加而提高。MgO显著促进了PA6的结晶过程,使其两个叠加的结晶宽峰变为一个尖锐的结晶峰,表明MgO的加入既促进了PA6的成核过程又促进了生长过程,使结晶速率显著提高,分步结晶过程消失,结晶过程的多层次性变弱。 相似文献
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利用鳞片石墨(FG)的高导热性能,采用熔融共混法将鳞片石墨填充于聚酰胺66(PA66)中,制备出FG/PA66导热复合材料,研究了石墨填充量以及粒径对复合材料导热性能和力学性能的影响。研究表明:随着FG填充量的增加,复合材料的导热率显著增加,而力学性能逐渐降低。当填充量为50%时,导热率达到了3.07 W/(m·K),是纯PA66的12.3倍。力学性能在50%填充量时为最小值,拉伸强度和冲击强度分别为59.3 MPa和3.03 kJ/m~2。在相同填充量下,复合材料的导热率随着粒径增大而增大,当鳞片石墨的填充量为40%,填料粒径为150μm时,导热率达到最大值,为2.38 W/(m·K)。力学性能随粒径变化呈现先增大后减小的趋势,当粒径为100μm时,复合材料的力学性能最佳。 相似文献
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以聚酰胺6(PA6)为基体, 氮化硼(BN)作为导热填料,经双螺杆挤出机熔融共混,模压成型制得导热绝缘复合材料。研究了BN含量、粒径、形状和不同BN粒径复配对复合材料导热性能的影响,并研究了BN含量和粒径对复合材料绝缘性能的影响。结果表明,在各种粒径下,复合材料热导率均随BN填充量的增加而增大;在BN粒径为5 μm、填充量为25 %(体积分数,下同)时,复合材料热导率达到1.2187 W/(m·K);在BN填充量相同时,填料粒径对复合材料热导率的影响不是简单的单调规律,呈现50、100 μm时较小,1、5、15 μm时较大,150 μm时最大的规律;片状BN填料比球状BN填料更有利于提高复合材料的热导率;2种不同粒径填料复配所填充的复合材料的热导率大于单一粒径填充的复合材料;5 μm与150 μm粒径BN复配,在填充量为20 %,配比为1:3时,复合材料的热导率最大,达到1.3753 W/(m·K),为纯PA6的4.9倍;在不同BN含量和粒径下,复合材料体积电阻率均能达到10000000000000 Ω·cm以上,满足绝缘性能。 相似文献
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以绝缘导热填料氮化硼(BN)填充聚酰胺6(PA6)作为研究对象,选择双氨基硅烷偶联剂DAMO-T作为改性剂,分别用溶液法和物理分散法处理后的BN粒子填充PA6。通过对BN粒子进行红外光谱(FTIR)及复合材料扫描电镜(SEM)表征,测试了复合材料导热性能。结果表明,偶联剂DAMO-T与BN表面的悬挂键发生化学反应;显著缩小BN与PA6基体间的间隙并使两相间树脂带增多;未反应偶联剂在基体中会小幅降低导热系数;偶联剂DAMO-T与BN质量比为1∶5,BN填充量达到50%时,复合材料的导热系数可达1.812 W/(m·K)。 相似文献
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主要研制了导热聚对苯二甲酸丁二醇酯/聚酰胺复合材料(PBT/PA),选用纳米氧化镁(MgO)为导热填料。首先探讨了基体树脂配比PBT/PA对PBT/PA/MgO复合材料导热和力学性能的影响;然后固定基体树脂配比,考察了纳米氧化镁的添加量对PBT/PA/MgO复合体系的导热性能和力学性能的影响。实验结果表明,当PBT/PA配比为1∶1,纳米氧化镁添加量为40wt%时PBT/PA/MgO复合材料在保持一定的力学性能的基础上热导率达到0.787W/(m.K),表明该复合体系具有优良的导热性能和力学性能。此外还研究了不同加工方法对复合材料力学性能和导热性能的影响,采用二步法制备的复合材料的导热性能和力学性能较一步法更为优异。利用二步加工法,同时通过调节PBT/PA配比控制共混物的双连续相形态,从而制备出导热性能较好的PBT/PA/MgO复合材料。 相似文献
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聚丙烯/四针状氧化锌晶须/氧化镁导热绝缘复合材料的制备与性能研究 总被引:2,自引:0,他引:2
李光吉;童奇勇;冯晖 《中国塑料》2010,24(6):28-35
以聚丙烯(PP)为基体,四针状氧化锌晶须(T-ZnOw)和氧化镁(MgO)为导热填料,通过双螺杆挤出机制备了PP/T-ZnOw /MgO导热绝缘复合材料。在T-ZnOw用量为10 %(质量百分含量,下同),MgO用量在0~60 %的范围内,考察了MgO用量对复合材料的热导率( )、体积电阻率(ρv)、力学性能和加工性能的影响。结果表明,随着MgO用量的增加,PP/T-ZnOw /MgO复合材料的 增大,ρv减小;材料的拉伸强度和弯曲强度以及熔体流动速率均随着MgO用量的增加而下降,而冲击强度则呈先保持稳定,然后减小的趋势。这一变化趋势在MgO用量 30 %时较为显著。当MgO用量为60 %(33 %,体积分数)时,PP/T-ZnOw /MgO复合材料的 最大,达到0.7563 W/(m·K),比未加MgO时的PP/T-ZnOw复合材料和纯PP的热导率分别提高了108.0 %和210.0 %;此时材料的ρv最小,为9.20×1015 Ω·cm,仍可满足绝缘材料的要求。 相似文献
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A new method based on Enskog's hard sphere theory for dense fluids and the principle of corresponding states is presented for predicting thermal conductivity of pure organic liquids and their mixtures. The thermal conductivities of alkanes, isoalkanes, aromatics, aldehydes, esters and ketones were calculated using this method which requires only critical properties and normal boiling point as input data. The predictions were compared with experimental data and other prediction methods over a wide range of temperatures (0.3 < Tr < 0.8) and highly satisfactory results were obtained. The method was also extended to mixtures employing simple mixing rules for calculating mixture properties. 相似文献
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碳纳米管材料导热性能的实验研究 总被引:2,自引:0,他引:2
本文对碳纳米管与环氧树脂(Epoxy-EP)复合材料的导热性能进行了定量的研究,探索了CNTs/EP复合材料的制备方法,运用Hotdisk热常数分析仪研究了CNTs/EP复合材料的导热系数;利用CNTs/EP两相复合材料的导热理论模型得到了室温下单壁碳纳米管(Single-Wall Carbon Nanotubes-SWCNTs)的导热系数为3980 W/(m.K),双壁碳纳米管的导热系数(Double-Wall Carbon Nanotubes-DWCNTs)为3580 W/(m.K),以及多壁碳纳米管(Multi-Wall Carbon Nanotubes-MWCNTs)的导热系数为2860 W/(m.K)。 相似文献
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应用不同的理论模型预测了炭黑/橡胶复合材料的热导率,并与实验测试结果进行了对比分析.结果发现,发黑体积份数对炭黑填充胶热导率影响很大,随着炭黑用量的增加,炭黑/橡胶复合材料的热导率逐步增加;炭黑/橡胶复合材料的热导率与炭黑的结构性及形态有关;在低填充份数2%~25%范围内,用Maxwell模型预测N234发黑/橡胶及N134炭黑/橡胶两种复合材料的热导率与实验结果最为接近. 相似文献
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Steven M. Smith II Lun Feng William G. Fahrenholtz Gregory E. Hilmas Laura Silvestroni 《Journal of the American Ceramic Society》2023,106(1):632-638
Thermal and electrical properties were measured for TiB2 ceramics containing varying CrB2 contents up to 33 mol%. The room-temperature thermal diffusivity decreased with increasing Cr content from 0.330 ± 0.003 cm2/s for pure TiB2 to 0.060 ± 0.003 cm2/s for (Ti0.66Cr0.33)B2. The amount of anisotropy in the coefficients of thermal expansion increased with increasing Cr content and the c-axis had the greatest dependence on Cr addition, with an increase of more than 25% in the thermal expansion for 33 mol% CrB2 compared to TiB2, whereas the a-axis only increased by about 8%. The electrical conductivity was the lowest for (Ti0.66Cr0.33)B2 at ∼8.5 × 103 S/cm compared to ∼106.1 × 103 S/cm for nominally pure TiB2. Overall, the addition of CrB2 as a sintering aid for TiB2 was shown to have a significant effect on the thermal and electrical properties of TiB2 for additions as small as 5 mol% CrB2. 相似文献
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Meng Zhao Wei Pan Tianjun Li Muzhang Huang Yujia Huang Jun Yang Zheng Li Chunlei Wan 《Journal of the American Ceramic Society》2019,102(4):1961-1970
Yttria-stabilized zirconia (YSZ) has been considered as state-of-the-art material for high-temperature thermal barrier coatings, which provide thermal insulation to the superalloy components in gas turbines and jet engines. Oxygen vacancies induced by yttria substitutions are believed to be mainly responsible for the low thermal conductivity of YSZ due to their phonon scattering effect. However, high mobility of oxygen vacancies in YSZ leads to a rapid oxygen diffusion at high temperatures, therefore accelerates the failure of coatings by grain coarsening, sintering, and simultaneous oxidation of the underlying metallic bondcoat. In the present research, we further explored in the ZrO2–Ln2O3 binary phase diagram and synthesized a series of ceramic materials with the chemical formula of Zr3Ln4O12 (Ln = La, Gd, Y, Er, and Yb), in which more oxygen vacancies were involved and extremely low phonon thermal conductivities (1.3-1.6 W/m·K) were obtained, even approaching to the theoretical minimum. In addition, the mobility of these oxygen vacancies was remarkably suppressed by the lattice ordering with the decrease of Ln3+ radius, as confirmed by X-ray diffraction, Raman and transmission electron microscopy. Thus, the oxygen barrier property and sintering resistance were significantly enhanced accordingly, which makes Zr3Ln4O12 compounds promising thermal barrier coating materials for next generation gas turbines and jet engines. 相似文献
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概述了导热硅橡胶的导热模型与导热机理;介绍了国内外导热硅橡胶的研制与开发情况,提出了提高硅橡胶导热性能的三种途径;阐述了导热硅橡胶的应用及发展方向。 相似文献