膨胀石墨/石蜡复合相变材料的制备与物性研究

Preparation and Physical Properties of Expanded Graphite/Paraffin Composite Phase Change Materials

本文采用SEM、DSC和TPS等方法表征材料特性,研究了由石蜡和不同粉碎程度、不同质量分数的膨胀石墨组成的复合材料的物性,分析了复合材料的密度、相变特性和导热系数随膨胀石墨粉碎程度和质量分数的变化规律。结果表明:膨胀石墨粉碎程度由1级到4级,复合材料密度的平均误差从3.45%升到7.65%;相变温度变化在4.44℃以内;比热容变化无明显规律;相变潜热值比纯石蜡低3.64%~32.68%,潜热与膨胀石墨含量负相关,与粉碎程度正相关;复合材料相比纯石蜡的导热能力增加了43.1%~87.5%,随着粉碎程度从1级增大到4级,膨胀石墨质量分数为2%的复合材料导热系数减小了23.7%。

In this paper, SEM, DSC, TPS and other methods are used to characterize material properties, and the physical properties of composite materials composed of paraffin wax and expanded graphite with different pulverization degrees and different mass fractions are studied. The density, phase change characteristics and thermal conductivity of the composite material are analyzed as a function of the degree of pulverization and mass fraction of expanded graphite. The results show that as the degree of pulverization of expanded graphite increases from level 1 to level 4, the average error of composite material density rises from 3.45% to 7.65%;the phase transition temperature changes within 4.44 ℃;the specific heat capacity changes without obvious law;the latent heat value of phase change is 3.64%-32.68% lower than that of pure paraffin. The latent heat is negatively correlated with the content of expanded graphite, and positively correlated with the degree of pulverization;Compared with pure paraffin, the thermal conductivity of the composite material increases by 43.1%-87.5%. As the degree of pulverization increases from level 1 to level 4, the thermal conductivity of the composite material with a mass fraction of expanded graphite of 2% decreases by 23.7%.