针对传统定形相变材料刚性大无法用于紧凑空间热控的问题,通过制备各向异性柔性复合相变材料(FPCM)来改善相变热管理系统的接触传热。通过定向冷冻干燥法将膨胀石墨(EG)制备成各向异性导热增强材料碳气凝胶(CA),以石蜡(PA)作为相变基体,以烯烃嵌段共聚物(OBC)作为柔性载体材料。利用熔融共混法制备FPCM,并对其热物性参数进行分析。结果表明:当CA含量为12%、压实密度为860kg/m3时,FPCM的轴向和径向热导率分别为8.1W/(m·K)和3.4W/(m·K),表现出显著的各向异性热导率。加入32% OBC时FPCM的泄漏率为0.42%,表现出优异的热稳定性和柔性。
Aiming at the problem that the rigidity of traditional shaped phase change materials is too large to be used for compact space thermal control,anisotropic flexible composite phase change materials (FPCMs) were prepared to improve the contact heat transfer in phase change thermal management systems.Anisotropic thermally conductive carbon aerogels (CAs) were prepared from expanded graphite (EG) by directional freeze-drying method with paraffin (PA) as the phase change matrix and olefin block copolymer (OBC) as the flexible carrier material.The FPCM was prepared by melt blending method and its thermophysical parameters were analyzed.The experiments showed that the axial and radial thermal conductivities of FPCM were 8.1W/(m·K) and 3.4W/(m·K),respectively,when the CA content was 12% and the compacted density was 860 kg/m3,which exhibited significant anisotropic thermal conductivity.The leakage rate of FPCM with the addition of 32% OBC was 0.42%,showing excellent thermal stability and flexibility.
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基金资助
河南省科学技术厅自然科学基金项目(232300420310);河南省粮油仓储建筑与安全重点实验室开放课题基金项目(2021KF-A03)
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