聚乙二醇/氮化硼复合材料相变导热性能及其结晶行为

本文采用熔融共混浇筑的方法制备了聚乙二醇/氮化硼(PEG/BN)相变复合材料,并研究了不同尺度片状BN对相变复合材料导热性能和结晶行为的影响。 通过扫描电子显微镜(SEM)、热常数分析仪、红外热成像分析仪和差示扫描量热仪(DSC)研究了相变复合材料的微观形貌、导热系数和相变过程,并利用莫志深法对DSC结果进行了非等温结晶动力学分析。 结果表明,较大片状直径(50 μm)的BN可以更有效地提高聚乙二醇的导热系数,当BN填料质量分数为40%时,相变复合材料的导热系数可达到5.04 W/(m·K)。 在快速降温条件下,片径为50 μm的BN填料可以缩短PEG的半结晶时间,提高结晶速率,使相变复合材料具有较大的相变焓。

Thermal Conductivity and Crystallization Behavior of Polyethylene Glycol/Boron Nitride Phase Change Composites

In this paper, polyethylene glycol/boron nitride (PEG/BN) phase change composite was prepared by molten blending method and the influence of the flake size of BN on the thermal conductivity and crystallization behavior of phase change composites was studied. The microstructure, thermal conductivity and phase transition performance of the prepared composites were investigated by scanning electron microscope (SEM), thermal constant analyzer, infrared thermal imaging analyzer and differential scanning calorimeter (DSC). The DSC results of were analyzed by Mo Zhishen method. Results show that larger diameter (50 μm) BN can improve the thermal conductivity of PEG more effectively. When the weight fraction of BN filler content is 40%, the thermal conductivity of phase change composite can reach 5.04 W/(m·K). Under conditions of rapid cooling, BN filler with a diameter of 50 μm can shorten the semi crystallization time and increase the crystallization rate of PEG, and make the phase change composites have a large phase change enthalpy.