高介电低损耗的新型聚芳醚腈耐高温介电材料

In this project, a series of novel polyarylene ether nitrile copolymers (PENs) with high dielectric constant and low dielectric loss have been designed and synthesized from polyphenol and 2, 6-dichlorobenzonitrile via nucleophilic aromatic substitution polymerization. The performances of obtained PENs can be controlled and optimized by controlling the copolymer structure, and crosslinking network structures can be formed to reduce the dielectric loss by treating at high temperatures. Then, polymer/inorganic filler composites were prepared with PENs as matrices, dielectric and conductive fillers as the dispersed phase. Chemical surface modification, physical encapulsate, and continuous ultrasonic technology were developed to improve the dispersion states of nano-fillers. scanning electron microscopy, transmission electron microscopy, dynamical rheological measurements were employed to control filler dispersion state and composite morphology along with the compatibility between polymer and filler, and Infrared spectra and mass spectrograph were used to characterize the tructures of obtained composites. Thermal and dielectric properties of both neat PENs and their composites were evaluated comprehensively, especially the dielectric property-temperature relationship, and the structure-performance relationship of the PENs and the performance index of the composites were obtained. These materials will have a variety of advantages, such as good heat resistance, high energy density, low dielectric loss, good stability of dielectric properties in high temperature conditions (above 150 ℃) and so on. They will have potential applications in high energy storage film capacitors.

设计合成新型多元酚与2,6-二氯苯甲腈通过亲核芳香取代反应合成新型聚芳醚腈，获得具有高介电常数、低介电损耗的耐高温聚合物基体材料，并通过对聚合物结构的调控来实现性能的调控和优化。通过高温交联形成交联网络结构来降低聚芳醚腈的介电损耗。采用介电纳米填料和导电纳米填料为分散相，制备聚芳醚腈/纳米填料复合的介电材料，通过纳米粒子的表面化学接枝、物理包覆及连续超声分散技术来解决两相之间界面相容性问题和纳米填料的分散性问题，而实现降低界面损耗的目标。应用红外光谱、核磁共振谱对材料的结构进行分析，透射电子显微镜、动态旋转流变技术来控制材料的分散形态及两相相容性。对材料的热性能、介电性能进行全面评价，尤其是介电性能-温度特性。获得一种兼备耐热性能好、高储能密度、低介电损耗、高温条件下（150℃以上）介电性能稳定性好等优点的介电材料，并开发其在耐高温高储能电容器领域的应用。

具有耐高温、高介电常数、低介电损耗特征的聚合物基介电复合材料被认为是高性能介电材料中极具竞争优势的品种之一。本项目以聚芳醚腈为聚合物基体材料，分别从聚合物分子链结构设计、聚集态结构控制、界面化学反应优化、复合材料界面精细结构调控等多层次多角度全面研究了聚芳醚腈结构与介电性能的构效关系。具体而言，借助二卤苯甲腈与二元酚的亲核取代缩聚反应，合成了包括均聚型、共聚型、交联型等不同分子链结构的聚芳醚腈，详细研究了系列聚合物的介电性能与分子链结构的对应关系。在此基础之上，分别从有机填料和无机填料两个角度，制备了具有增强介电性能的聚芳醚腈复合材料。以双邻苯二甲腈和聚苯胺为有机填料对聚芳醚腈进行增强填充，获得了系列具有良好界面相容性与优良介电性能的全有机介电复合材料；以钛酸钡、二氧化钛、碳纳米管、氧化石墨烯等无机刚性粒子为功能填料，引入侧链羧基化聚芳醚腈、氨基化邻苯二甲腈、超支化酞菁铜等有机组分进行界面化学增强，有效改善有机基体与无机组分的界面相容性，获得了一系列具有高介电常数与低介电损耗的有机无机介电复合材料。最后，运用热拉伸取向与大分子端基化学交联等技术手段，对聚芳醚腈介电薄膜的聚集态结构与复合材料的界面精细结构进行有效调控，二次热拉伸有效改善了功能填料在聚芳醚腈基体中的分散状况，而大分子端基化学反应形成的交联网络则显著降低了介电损耗并大幅度提高耐热温度，从而最终获得具有高介电常数、高介电击穿强度、低介电损耗的耐高温有机无机介电复合材料，为研制耐高温高储能密度薄膜电容器提供了理想的高性能介质材料。在本项目的资助下，已发表SCI论文50篇，申请中国发明专利4项，获得四川省科学技术发明奖一项，培养博士及硕士研究生共计26人，多次在国际及国内学术及行业会议上展示项目研究成果，有效提升了聚芳醚腈介电复合材料在储能器件领域的影响力，为未来进行聚芳醚腈介电复合材料的产业化开发奠定了良好的基础。