【作者】 殷景华；

【导师】 雷清泉；

【作者基本信息】 哈尔滨理工大学 ， 高电压与绝缘技术， 2006， 博士

【摘要】 本文采用X射线衍射和小角X射线散射分析、扫描电镜、透射电镜分析及材料结构与性能模拟软件等方法，研究溶胶-凝胶方法制备无机纳米颗粒杂化聚酰亚胺薄膜和Dupont 100CR薄膜显微结构、纳米颗粒的分布、大小、形状，以及在DC阶梯电场作用下，Dupont 100CR杂化薄膜与Dupont100 HN普通薄膜的击穿特件及击穿机理。 采用Materials Studio软件模拟PI和纳米杂化PI薄膜电子结构、几何结构及能量状态。模拟结果表明，在能量最低和几何结构优化基础上，PI／α-Al₂O₃体系总能量比PI／SiO₂低得多，范德华能比PI／SiO₂高出约十倍，PI／α-Al₂O₃体系比PI／SiO₂体系更稳定，与实验结果相一致。 SEM和TEM观察表明，采用溶胶-凝胶方法制备的纳米杂化薄膜中含有SiO₂团簇和Al₂O₃颗粒，SiO₂团簇结构不稳定，在高能电子束照射下易分解，Al₂O₃颗粒结构稳定；SAXS分析表明，该薄膜的分形维数比扩散限制凝聚模型（DLA）的理论值大，团簇是由大量小颗粒构成。 SEM、TEM和XRD测试结果表明，Dupont 100CR纳米掺杂薄膜中只含有Al₂O₃颗粒，颗粒主要分布在聚酰亚胺有序大分子区域的边界上，在高能电子束照射下Al₂O₃颗粒结构稳定；薄膜分形维数接近于三维扩散限制凝聚模型（DLA）的理论值，粒子的回旋半径与实验测试结果一致。 采用DC阶梯升压方式，研究Dupont 100CR杂化薄膜和Dupont 100HN普通薄膜击穿特性，击穿属稳态热击穿类型，出现直径为200 μm的丝状孔洞。研究结果表明，两种薄膜击穿孔及周围形貌存在明显差别：100CR击穿孔边缘粗糙不平，破坏范围只在孔附近；100HN变形区域很光滑且破坏范围大，变形区为一个个突起的区域。 研究结果表明，无机纳米颗粒改变了PI薄膜基体的结构环境，起到了改善导热、提高耐电晕性、降低热损伤以及阻止电极损坏等作用。更多还原

【Abstract】 The microstructure of the film, distribution, shape and size of inorganic nanoparticle in hybrid PI film prepared by sol-gel method and Dupont 100 CR film have been studied by means of XRD, SAXS, SEM, TEM and materials structure and property simulation soft. Under UC step electrics field, the breakdown property and mechanism of Dupont 100 CR and 100 HN have also been studied.The electrons structure, geometric structure and energy state of PI and nanohybrid PI have been studied by Materials Studio. The results show that the whole energy of PI/α -Al₂O₃ system is more lower than that of PI/SiO₂ under the basic of the lowest energy and optimized geometric structure. The energy of Van der Waals of PI/α -Al₂O₃ is higher 10 times than that of PI/SiO₂, thus the system of PI/α -Al₂O₃ is more stable than that of PI/SiO₂, and the conclusions are consistent with the experiment results.SEM and TEM observations show that the nanohybrid films prepared by sol-gel contain SiO₂ clusters and A1₂O₃ particles. Under the high energy electron beam bombarding, compared with the structure of SiO₂ clusters decomposed, the structures of Al₂O₃ particles are rather stable. The SAXS analysis show that the fractional dimensions of the film is larger than the theory value of Diffusion Limited Aggregation （DLA） and the clusters consist of a great number of small particles.The measuring results of SEM, TEM and XRD show that Dupont 100CR films only contain Al₂O₃ particles and the most of particles distribute on the domains （making up of arranged macromolecule） interface of PI. Under the high energy electron beam bombarding, the structures of Al₂O₃ particles are stable. The fractional dimensions of the film close to the theory value of DLA and the rotary radius agrees with the experiment results.Raising DC voltage by step, the breakdown characteristics of 100CR and 100HN films have been studied. The results show that the film breakdown belongs to stable heat type accompanying a wire hole with 200 μm in radius. The results show that breakdown holes for both films have obviously differences. The hole edges are coarse and uneven for 100CR and the damage zone is only around the hole. But for 100HN, the deformation zones are smooth and the damage zones are large forming many projection zones.The research results show that the inorganic nanoparticles change environment of PI matrix and play a role of improving thermal conductivity, increasing corona-resistance, decreasing heat damage and preventing electrode damage.更多还原