【作者】 卢同红；

【导师】 王翔；

【作者基本信息】 武汉理工大学 ， 材料学， 2009， 硕士

【摘要】 现代电子科技的迅猛发展,对电子材料的介电性能提出了越来越高的要求,迫切需要具有高介电常数、低损耗、同时具有较高力学性能和可加工性能的介电材料,这就使得高介电常数材料的重要性日益显著。复合材料能兼容陶瓷粒子的高介电性能以及聚合物优良的机械性能和绝缘性,是当前介电材料领域研究的主要方向之一。将陶瓷粉体与聚合物进行复合是制备具有高介电常数且易加工的复合材料的一种很有前景的方法。这类以高介电常数的陶瓷粉未分散于三维连续的聚合物基体中形成的聚合物基复合材料在电子领域具有广泛的应用,近年来,在高储能电容器中的应用也引起了广泛关注。本文以环氧树脂作为基体,以纳米BaTiO₃为高介电填充组分,引入羰基铁粉为第三组分,用浇铸法制备了纳米BaTiO₃/环氧树脂二相复合材料和纳米BaTiO₃/环氧树脂/Fe三相复合材料。分别测试了其介电性能和力学性能,并对复合材料的微观形貌进行了表征。选择两种硅烷偶联剂对二相复合材料体系中纳米钛酸钡进行表面处理后与环氧树脂基体复合。比较偶联剂对复合材料介电性能、热性能及力学性能的影响。结果表明,采用KH550硅烷偶联剂处理后的复合材料具有较佳的介电性能及力学性能,且纳米钛酸钡在基体中分散效果也较好;纳米钛酸钡填充含量对复合材料的两相界面和介电性能有很大的影响;随着纳米BaTiO₃的加入以及含量的增加,材料体系的热分解温度有一定的提高。通过对三相体系介电性能的研究,结果发现:羰基铁粉的含量对材料的介电常数有显著的影响;SEM显示,羰基铁粉含量的增加有利于其在基体中均匀分散。其中羰基铁粉的加入量较低,仅为1%-7%质量分数。羰基铁粉的加入无论对较低含量还是较高含量的体系其影响基本一致,即均导致了介电常数和介电损耗的增加。在钛酸钡含量较高时,少量羰基铁粉的加入就造成了介电损耗的急剧上升。这主要是因为导电组分的加入增加了体系的电导电流,从而引起电导损耗上升。从提高材料介电性能的角度,羰基铁粉的加入提高了其介电常数,但同时也导致其介电损耗的增加。因此对三相体系需要更精确地选择第三导电组分的种类和控制其含量,以及调控它们在复合材料中的分散形貌,以达到同时改善其介电常数和介电损耗的目的。更多还原

【Abstract】 Modern electronic technology in the rapid development of electronic materials for the dielectric properties put forward higher requirements,the urgent need for a high-k,low loss,at the same time with high mechanical and processing properties, which on the high dielectric constant materials made of the importance of the growing significantly.Composite particles can be compatible with high dielectric properties of ceramic,as well as good insulation and mechanical properties of polymers,is one of the major directions in the field of study on the dielectric material. Composite materials are prepared by filled ceramic powder into the polymer to carry out a high dielectric constant and easy processing,which is a promising method.Such high dielectric constant of ceramic powder dispersed in a row of three-dimensional polymer matrix in the form of polymer matrix composites has a wide range of applications in the field of electronics.In recent years,high-energy storage capacitors in a wide range of applications also concern.In this paper,nano-BaTiO₃/Epoxy composite materials and nano-BaTiO₃/ Epoxy/Fe ternary composites were prepared by casting with epoxy resin as a matrix, nano-BaTiO₃ as higher dielectric filling components,the introduction of carbonyl iron powder for the third component.BaTiO₃ was treated by two of the silane coupling agents on the dual system of nano-composite materials and then was mixed into epoxy matrix.Dielectric properties and mechanical properties composite material were tested.Dielectric properties,thermal properties and mechanical properties were compared of the effect by using the coupling agent composite and morphology of the composite were characterized.The results showed that the composite treated by the silane coupling agent KH550 has the best dielectric properties and mechanical properties,and nano-BaTiO₃ dispersed in the matrix in the best;The concentration of nano-BaTiO₃ particles also has an effect on the Interface and the dielectric properties of composites; The material system of thermal decomposition temperature to increase to a certain with the accession nano-BaTiO₃ particles. The dielectric properties of the nano-BaTiO₃ / Epoxy / Fe composites system were studied.It was found that:the content of carbonyl iron powder had significantly effected on the dielectric constant of the material,in which the addition of carbonyl iron powder was low,only 1%-7%of the mass fraction;SEM showed that carbonyl iron content in favor of the increase in the uniform dispersion matrix..The impact on the system are basically the same with the addition of carbonyl iron content of both the lower or higher,which resulted in the dielectric constant and dielectric loss increased.In a high level with barium titanate,the small amount by addition of carbonyl iron resulted in the sharp rise on dielectric loss.This was mainly due to by the addition of conductive component of the conductivity increase of the current system,which led to increase the loss of conductivity.From the point of improving the material properties,by the addition of carbonyl iron powder,it could improve its dielectric constant,but it also led to an increase in dielectric loss.Therefore it was needed for more accurate selection of the third component types to control their content for three-phase system,as well as the regulation and control of composite materials in the dispersed morphology.In order to achieve and at the same time to improve its dielectric constant and dielectric loss,further study is also needed.The results for the ceramic/polymer matrix composite materials of high dielectric applications have laid a solid foundation.更多还原