界面区分子链运动特性对聚乙烯纳米复合电介质直流击穿的影响

项目名称： 界面区分子链运动特性对聚乙烯纳米复合电介质直流击穿的影响

项目编号： No.51507124

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 电工技术

项目作者： 闵道敏

作者单位： 西安交通大学

项目金额： 21万元

中文摘要： 聚合物纳米复合介质具有优异的介电性能，在高压电力设备和器件中有广泛的应用前景。其优异介电性能主要来源于纳米粒子与基体间的界面区。然而，由于界面区结构的复杂性，界面区特性与纳米复合电介质介电特性的关联尚不清楚，极大地限制了纳米复合电介质的发展和应用。本项目围绕聚乙烯纳米复合电介质的直流击穿展开研究，以界面区分子链运动特性为突破点，采用原子力显微镜研究界面区分子链段的弹性模量分布特性，通过太赫兹光谱、介电谱、热转变和动态力学松弛等手段，表征界面区分子链运动特性；采用热刺激电流、表面电位衰减和空间电荷等测试方法表征介质的电荷输运特性。研究界面区分子链运动特性对介质电荷输运特性的影响规律及其电荷输运对分子链运动的作用机制，进而分析电荷输运特性的改变对介质直流击穿特性的影响机理。揭示界面区特性对聚乙烯纳米复合电介质直流击穿的作用机理。为高性能纳米复合电介质的发展与应用提供理论基础和实验依据。

中文关键词： 聚乙烯纳米复合电介质；界面区；分子链运动；电荷输运；直流击穿

英文摘要： Polymer nanocomposites have excellent dielectric properties, showing promising application in high voltage power equipment and device. The excellent dielectric properties originate from interfacial regions between nanoparticles and polymer. However, because of the complexity of interfacial region structures, the relationship between the interfacial region properties and the dielectric properties of nanocomposites is not very clear, limiting the development and application of nanocomposites tremendously. In the present project, special attentions are given to the molecular chain motion properties in interfacial regions to investigate the dc breakdown of polyethylene nanocomposites. Distributions of elastic modulus in interfacial regions will be measured by atomic force microscopy. Then, molecular chain motion properties in interfacial regions will be characterized by terahertz time domain spectroscopy, dielectric spectroscopy, thermal transition, and dynamical mechanical spectroscopy. In addition, charge transport properties of nanocomposites will be characterized by thermally stimulated current, surface potential decay, and space charge measurement methods. The influence of molecular chain motion properties in interfacial regions on charge transport behavior and the effect of charge transport on molecular chain motion will be analyzed. Subsequently, mechanism of dc breakdown strength of nanocomposites influenced by the change of charge transport properties will be analyzed. Finally, the effect mechanism of interfacial region properties on dc breakdown strength of polyethylene nanocomposites will be revealed. It can provide theoretical basis and experimental support for the development and application of high performance nanocomposites.

英文关键词： Polyethylene nanocomposites;interfacial region;molecular chain motion;charge transport;dc breakdown