basrtio3pvdf功能复合材料的设计 制备与电性能研究word格式论文.docx

能量存储密度为 0.35 J/cm3。采用 KH550 硅烷偶联剂改善陶瓷相和聚合物相的界面作用，研究了硅烷偶联剂改 性的 BST/PVDF 功能复合材料的微观组织结构与介电性能，结果表明 KH550 的偶联机 理为 BST 与 KH550 发生枝接反应生成 Si-O 共价键，而 PVDF 的氟原子与 KH550 的氨 基形成氢键；KH550 可有效提高 BST/PVDF 复合材料的界面相容性，改善 BST/PVDF 复合材料的介电性能和储能密度；优化出 KH550 硅烷偶联剂含量，4wt%KH550 处理的 BST/PVDF 复合材料具有最佳介电性能和储能密度，其介电常数为 56，介电损耗为 0.03， 可调性为 10.6%，储能密度为 1.05 J/cm3。采用对数混合规则、Maxwell 理论模型、Clausius-Mossotti 模型及 Yamada 模型对本 文制备的复合材料的介电常数进行数值模拟，结果表明 Yamada 模型的计算值和实验结 果匹配度最高，通过调节 Yamada 模型中陶瓷颗粒的形状因子参数能够很好拟合实验曲 线；采用 Devonshire 唯象理论模型对于复合材料的介电可调性进行数值模拟，并引入唯 象系数比值进行修正，修正后的 Devonshire 唯象理论模型适用于复合材料介电常数与陶 瓷相介电常数相差很大时的复合材料体系。关键词：钛酸锶钡，聚偏氟乙烯，偶联剂，介电性能，储能密度，可调性IIABSTRACTWith the rapid development of science and technology and interdisciplinary cross-penetration, a single performance of the materials cannot meet the needs of the integrated requirements. The functional composites become a research focus in the field of materials science and engineering. According to the characteristics of the ceramics and polymers, the ceramic/polymer composites can be prepared accompanying with advantages of the matrix materials. While the effects of the inner interface connection between the ceramics and the polymer, the ceramics phase and its content, and the interface reactions on the dielectric properties are still not clear, which restrained the applications and the development of the ceramic/polymer composite materials.In this thesis, the functional BST/PVDF composites with excellent dielectric tunable properties are prepared by advanced tape casting process using (BaSr)TiO3 and PVDF as matrix materials. The effects of the ceramics volume fraction and silane coupling agent KH550 contents on the microstructure and dielectric properties of BST/PVDF functional composites are investigated. Finally, the dielectric properties of BST/PVDF composites were simulated by the conventional theory models. Devonshire phenomenological theoretical model was modified by proposing the ratio of phenomenological coefficient.Firstly, The cerami