表层分子结构与纳米调控聚酰亚胺薄膜表面及空间电荷特性研究

发布时间：2018-03-12 23:09

本文选题：聚酰亚胺　切入点：分子结构　出处：《天津大学》2014年博士论文　论文类型：学位论文

【摘要】：聚酰亚胺作为一种特种工程材料，，被广泛应用于特高压电抗器、风力发电机、高速牵引电机等绕组绝缘材料，并在航空航天及微电子等领域有广泛的应用。但由于其作为有机物自身的缺陷，耐电性能不高，使用中过早击穿现象频发。绕组绝缘材料长期处于高温、高压、电晕与局部放电共同作用的复杂环境，导致电荷在绝缘内部迁移，在绝缘局部导致电荷累积，产生局部高场强，引起绝缘破坏及加速老化。表面和空间电荷的注入、积聚和运动规律，是材料的重要物理特性。本文研究了表层分子结构与纳米调控聚酰亚胺薄膜的表面及空间电荷动态特性，主要研究工作和取得的成果如下：（1）利用两步法制备了未添加纳米颗粒的聚酰亚胺薄膜，并通过原位聚合法制备了纳米Al2O3质量分数分别为1wt%、3wt%、5wt%、7wt%的纳米复合聚酰亚胺薄膜，通过扫描电子显微镜对纳米颗粒分散情况进行观测，测试了不同纳米颗粒含量试样的介电常数，得到了纳米颗粒对聚酰亚胺薄膜介电常数的影响规律。（2）利用搭建的表层分子结构调控系统对添加和未添加纳米颗粒的聚酰亚胺薄膜进行不同反应时间下的表层分子结构调控处理，并对调控后试样的化学结构特性、微观形貌特征、元素组成以及介电常数等性能进行分析，得到了表层分子结构与纳米调控对试样化学结构和形貌特征及介电常数的影响规律。（3）对直流电压作用下针板电极间的试样表面电荷动态特性进行分析研究，得到了表层分子结构调控以及纳米颗粒质量分数对试样表面电荷积聚、消散特性的影响规律，总结了表层分子结构调控及纳米调控对聚酰亚胺陷阱能级分布的影响规律，并采用固体能级分布及表面电子态理论解释了影响表面电荷动态特性的原因及运动方式。（4）通过表层分子结构调控反应时间对多层叠加试样空间电荷分布、内部电场强度及注入电荷量的分析，得到了多层叠加聚酰亚胺薄膜内空间电荷的分布特性。通过对试样电导率的测试，得到了表层分子结构调控反应时间对聚酰亚胺电导率的影响规律。
[Abstract]:Polyimide as a kind of special engineering materials, is widely used in high voltage reactor, wind generator, high speed traction motor winding insulation material, and is widely used in the fields of aerospace and microelectronics. But because of its own defects as organic matter, electric performance is not high, the use of the phenomenon of frequent premature breakdown. The winding insulation a long time at high temperature, high pressure, complex environment interaction of corona and partial discharge, resulting in charge in insulation insulation of internal migration, leading to local charge accumulation, produce local high electric insulation, causing damage and accelerated aging. The surface and space charge injection, accumulation and movement, is an important physical properties of the material in this paper. Study on the dynamic characteristics of the surface structure and nano surface molecular regulation of polyimide film and space charge, the main research work and achievements are as follows:
(1) polyimide film without adding nano particles prepared by two step method, and were prepared by in-situ polymerization of nano Al2O3 content were 1wt%, 3wt%, 5wt%, 7wt% nano composite polyimide film, by scanning electron microscopy of nano particles were observed, the dielectric constant of samples with different content of nano particles the test, obtains the influence law of nanoparticles on polyimide film dielectric constant.
(2) the surface molecular structure regulation of different reaction time on adding and without adding nano particles of polyimide film under treatment using surface molecular structure control system is developed, and the chemical structure characteristics of samples after regulation, microstructure analysis, element composition and dielectric properties, and obtains the influence law of structure and the surface of nano molecular samples of chemical structure and morphology and dielectric constant.
(3) to analyze the dynamic characteristics of surface charge effect of DC voltage between the needle plate electrode, the surface molecular structure regulation and nanoparticle mass fraction on the surface charge accumulation and dissipation characteristics influence, summarizes the molecular structure and surface control regulation on the influence of polyimide nano trap level distribution, solid energy distribution and surface electronic states using the theory and explains the dynamic characteristics and the effect of surface charge motion.
(4) the multi-layer sample space charge distribution by surface molecular structure to control the reaction time, the internal electric field and charge injection quantity analysis, obtained distribution characteristics of multilayer polyimide film space charge. After the sample conductivity test, obtains the influence law of the surface molecular structure regulation of reaction time on the conductivity of the polyimide.

【学位授予单位】：天津大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TM21

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