微观结构及拉伸倍率对电容器聚丙烯薄膜介电性能的影响  

Effect of Micro-structure and Stretching Ratio on Dielectric Properties of Polypropylene Films for Capacitors

作　　者：邢照亮 杜潇丹 杜伯学 肖萌 郭少玮 郝建红 XING Zhaoliang;DU Xiaodan;DU Boxue;XIAO Meng;GUO Shaowei;HAO Jianhong(State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources,North China Electric Power University,Beijing 102206,China;State Key Laboratory of Advanced Power Transmission Technology,State Grid Smart Grid Research Institute Co.,Ltd.,Beijing 102209,China;School of Electrical and Information Engineering,Tianjin University,Tianjin 300072,China)

机构地区：[1]新能源电力系统全国重点实验室(华北电力大学),北京102206 [2]先进输电技术全国重点实验室(国网智能电网研究院有限公司),北京102209 [3]天津大学电气自动化与信息工程学院,天津300072

出　　处：《高电压技术》2024年第6期2344-2353,共10页High Voltage Engineering

基　　金：国家自然科学基金(92266111,52177023,U1966203);国家电网公司总部科技项目(5500-202358774A-3-6-ZX)。

摘　　要：聚丙烯薄膜是电力电容器中应用最广泛的储能介质,其介电性能取决于粒料微观结构及拉伸工艺参数。该文以不同等规度的聚丙烯粒料为研究对象,采用不同拉伸倍率获得聚丙烯薄膜,研究了不同聚丙烯薄膜的表面形貌及结晶特性,分析了不同温度下聚丙烯薄膜电导率、介质损耗、击穿强度及储能特性等介电性能,探究了微观结构参数及拉伸倍率对聚丙烯薄膜介电性能的影响机理。研究结果表明:等规度为99.6%、拉伸倍率为4×5的聚丙烯薄膜试样电导率最低、击穿强度最高;等规度的提升能够增强分子链的热稳定性,改善聚丙烯非晶区分子链的松散结构,阻止电弱点的发展;此外,合理的拉伸倍率能够使聚丙烯的分子链发生取向排列,形成有序的结晶形态,从而提高结晶度。研究结果可为聚丙烯薄膜介电性能的提升提供实验与理论支撑。Polypropylene film is the most widely used energy storage medium in power capacitors,and its dielectric properties depend on the micro-structure of the particles and stretching process parameters.In this paper,polypropylene pellets with different isotacticity were taken as the research object,and polypropylene films were obtained by different stretching ratios.The surface morphology and crystallization characteristics of different polypropylene films were studied,the dielectric loss,breakdown strength,and energy storage chareacteristics of polypropylene films under different temperatures were analyzed.The influence mechanism of micro-structure parameters and stretching ratio on dielectric properties of polypropylene films was investigated.The results show that the polypropylene film sample with isotacticity of 99.6%and stretching ratio of 4×5 has the lowest conductivity and the highest breakdown strength.The improvement of the isotacticity can enhance the thermal stability of the molecular chain,improve the loose structure of the molecular chain in the amorphous region of polypropylene,and prevent the development of electrical weaknesses.In addition,a reasonable stretching ratio can enable the molecular chains of polypropylene to align and form an orderly crystalline morphology,and to increase the crystallinity.The research results can provide experimental and theoretical support for the improvement of dielectric properties of polypropylene films.

关 键 词：等规度 拉伸倍率 薄膜电容器 聚丙烯薄膜 介电性能 导电率 击穿强度 

分 类 号：TB383.2[一般工业技术—材料科学与工程] TQ325.14[化学工程—合成树脂塑料工业] TM53[电气工程—电器]