基于扫描热显微技术的氮化硼/低密度聚乙烯复合材料界面导热性能研究  

Study on Interface Thermal Conductivity of Boron Nitride/Low Density Polyethylene Composite Materials Based on Scanning Thermal Microscopy

作　　者：陈承相 朱玲颉 贾贝贝 李永飞 姜映烨 周峻[1] 吴锴[1] CHEN Chengxiang;ZHU Lingjie;JIA Beibei;LI Yongfei;JIANG Yingye;ZHOU Jun;WU Kai(Xi'an Jiaotong University,Xi'an 710049,China;Changzhou Power Supply Company of State Grid Jiangsu Electric Power Co.,Ltd.,Changzhou 213003,China;Shenzhen Power Supply Co.,Ltd.,China Southern Power Grid,Shenzhen 518048,China)

机构地区：[1]西安交通大学,陕西西安710049 [2]国网江苏省电力公司常州供电公司,江苏常州213003 [3]深圳供电局有限公司,广东深圳518048

出　　处：《绝缘材料》2021年第6期18-25,共8页Insulating Materials

基　　金：国家重点研发计划项目(2017YFB0903803)。

摘　　要：导热高分子复合材料基体和填料形成的界面会影响复合材料整体的导热性能。然而受到传统测试技术的限制,很难从微观角度更深入地研究界面导热机理。本文利用扫描热显微镜(SThM)研究了氮化硼(BN)/低密度聚乙烯(LDPE)复合材料的界面导热机制,对BN/LDPE复合材料的界面热学性质进行了定量分析,并通过有限元仿真模拟了SThM的测试过程,揭示了无机-有机界面处的界面热传导过程。结果表明:随着BN颗粒含量的增加,复合材料的热导率也随之提高。当BN的质量分数达到20%时,复合材料的热导率提高了约22%。采用SThM得到了微纳尺度样品形貌和反映热学性质的电压分布图像,发现BN/LDPE复合材料的热导界面宽度为150~200 nm。在两个BN颗粒相互接触的地方,显示高导热区间增大,热导界面宽度变化较小。通过测试标样获得了热导率与输出电压平方的拟合关系曲线,并计算得到BN/LDPE复合材料的界面热导率为0.33~39.81 W/(m·K)。仿真结果表明探针针尖能够区分填料、界面以及基体,复合材料的导热性能随着界面宽度和热导率的增大而提高。The interface of thermal conductive polymer composite matrix and filler can affect the overall thermal conductivity of the composite.However,limited by traditional testing technologies,it is difficult to study the interface thermal conduction mechanism from microscopic view.In this paper,the interface thermal conduction mechanism of boron nitride(BN)/low density polyethylene(LDPE)composites was studied by scanning thermal microscope(SThM),and the interface thermal properties of the BN/LDPE composites were analyzed quantitatively.The test process of SThM was simulated by finite element analysis,and the interface thermal conduction process at the inorganic-organic interface was revealed.The results show that with the increase of BN content,the thermal conductivity of the composite increases.When the mass fraction of the BN reaches 20%,the thermal conductivity of the composite increases by 22%.The sample morphology in micro-nano scale and the voltage distribution image reflecting the thermal properties were obtained by SThM,it is found that the thermal conductivity interface width of the BN/LDPE composite is 150–200 nm.At the area that two BN particles are in contact with each other,the high thermal conductivity area increases,and the thermal conductivity interface width changes little.The fitting curve between thermal conductivity and the square of output voltage is obtained by testing the standard samples,and the interface thermal conductivity of the BN/LDPE composites is calculated to be 0.33–39.81 W/(m·K).The simulation results show that the probe tip can distinguish the filler,interface,and matrix,and the thermal conductivity of the composite increases with the increase of the interface width and thermal conductivity.

关 键 词：SThM LDPE基复合材料 界面热传导 有限元仿真 

分 类 号：TM215[一般工业技术—材料科学与工程]