随着埋入式电容器的发展,具有高介电性能聚合物基复合材料的研究显得尤为重要.目前,高介电聚合物基复合材料主要有两种,铁电陶瓷/聚合物复合材料和导电颗粒/聚合物复合材料.综述了这两种复合材料的特点和最新研究进展,概述了可以增强聚合物基复合材料介电性能的方法.首先针对铁电陶瓷/聚合物复合材料介电常数难以提高的缺点,指出通过高介电聚合物基体的选择、陶瓷填料含量与尺寸形貌的控制,可以有效地提高这类材料的介电常数;同时介绍了这类复合材料不同界面结构和稳固界面的重要性,重点阐述了形成化学键连接的“分子桥”结构的方法;然后针对导电颗粒/聚合物复合材料渗流阈值难以控制和介电损耗高的问题,探讨了影响渗流阈值的因素和减小介电损耗的方法;最后基于本课题组在功能性纳米填料、高介电聚合物复合材料的基础研究及应用探索方面的工作积累,对高介电聚合物基复合材料的未来发展方向做出展望.
With the development of the embedded capacitors,researches on the high dielectric properties of polymer matrix composites are becoming more and more important.At present,there are mainly two types of high-k polymer matrix composites,ferroelectric ceramic/polymer composites and conductive particle/polymer composites.The characteristics and research progresses of the two different composites are briefly introduced,respectively.In addition,the methods which can effectively enhance the dielectric properties of the composites are summarized.At first,considering the disadvantage of low dielectric constant of the ferroelectric ceramic/polymer composites,we come up with some strategies that can availably solve this issue,such as selecting polymer matrix with high permittivity,controlling the content,size and morphology of the ceramic fillers.Additionally,the interface structure and importance of forming stable interface are introduced.To form the chemically bonded interface,the methods of preparing the "molecular bridge" structure are focused on.Secondly,to control the percolation threshold and reduce the high dielectric loss of conductive particle/polymer composites,the influencing factors of the percolation threshold and methods of reducing the dielectric loss are analyzed.Finally,the review concludes with an outlook on the future developments of the high-k polymer matrix composites based on our recently works on the controlled synthesis various nanofillers,high-k polymer composites and their applications.