聚苯胺纤维修饰铁氧体吸波功能体新结构及其与双马来酰亚胺相互作用机理

Due to low cost and good absorbing performance, the ferrite absorbers have been widely used in military stealth area. In order to reduce the high cost caused by the extra weight and frequent maintenance of the ferrite coating absorbers, a novel “urchin-liked” structure of polyaniline fibers modified ferrite electromagnetic wave absorption functional systems is designed in present research, in addition, a kind of structure-function integration composite with both high efficient absorbing and reliable bearing properties is put forward by combining the as-prepared functional system with BMI resin. Specific research work is as follows: the preparation technology of “urchin-liked” functional system of ferrite modified by polyaniline fiber will be explored, in addition, the functional system of ferrite modified by polyaniline fibers with good impedance matching and high absorbing ability will be designed and optimized, what´s more, the polarization mechanism of the interface between ferrite and polyaniline will be studied, and related interfacial polarization model will be constructed; the polarization mechanism of BMI resin will be researched from room temperature to 200 ℃ by molecular dynamics simulation method, and on this basis, the BMI´s molecular chain will be further modified to achieve good electromagnetic wave permeability at high temperature; the interfacial adhesion behaviors of ferrite, PANI and BMI will be investigated, moreover, the multi-interfacial polarization models among PANI, ferrite and BMI will be established, and finite element models of electromagnetic wave absorption functional system/BMI composites about mechanical properties will be built based on the cohesive zone model.

低廉的价格和良好的吸波性能使铁氧体在军用隐身领域获得广泛应用。为了克服涂覆型铁氧体吸波材料额外增重大以及维护频繁而导致成本高昂的缺点，本课题设计出聚苯胺纤维修饰铁氧体的“海胆状”吸波功能体新结构，并将功能体与BMI复合获得兼具高效吸波与可靠承载的结构功能一体化材料体系。具体研究包括，探索聚苯胺纤维修饰铁氧体的“海胆状”吸波功能体的制备工艺，优化设计出具有阻抗匹配好、电磁波吸收能力强的聚苯胺纤维修饰铁氧体功能体，研究铁氧体与聚苯胺界面处的极化规律，建立界面极化模型；采用分子动力学模拟的方法研究BMI从室温至200℃的极化机制，在此基础上进一步对BMI分子链进行修饰，达到提高其高温透波性能的目的；分别考察铁氧体、聚苯胺与BMI之间界面结合行为，建立复合材料中聚苯胺、铁氧体和BMI三者之间的多界面极化模型以及基于内聚力模型的吸波功能体/BMI复合材料力学性能有限元模型。

以航空业为代表的现代工业设计对材料的强韧性以及功能完备性提出越来越严格的要求，开发轻量化、多用途化的结构功能一体复合材料是未来发展的必然趋势。在此背景下，本课题选择低频吸波能力优异的铁氧体与高频吸收能力好的聚苯胺纤维进行复合，制备出性能优异的“海胆状”结构吸波功能体，进一步将其与改性BMI进行复合形成具有优良的吸波性能、良好的力学性能和耐候性的新型结构功能一体化复合材料，并建立相关模型进行模拟计算。.在吸波功能体方面，本项目研究了聚苯胺纤维在铁氧体表面生长所形成的“海胆状”结构功能体的制备工艺；探索出了聚苯胺纤维的长度、直径以及电导率对其电磁性能的影响规律，制备出了吸波能力强、吸收频带宽的吸波功能体材料，其中C2N4Z4F/PANI-1/1吸波剂在厚度仅为2.4mm时，有效吸收频带宽至6.8GHz(11.2~18GHz)；揭示了聚苯胺对铁氧体的饱和磁化强度、居里温度和磁损耗性能的影响规律；建立了铁氧体与聚苯胺之间的界面极化模型。.在BMI基体方面，探索出了BMI的相组成及其微观形貌形成机制，获得了相组成对其介电性能的影响规律；揭示了BMI从室温至200℃的极化机制和损耗机制；优化制备出了具有较低介电常数和损耗角正切(tanδ)的高温高透波BMI树脂基体材料。.在吸波功能体和BMI基体相互作用机理方面，探索出了功能体的含量、形貌、分布及其界面结合状况对复合材料电磁性能和力学性能的影响规律；揭示了铁氧体与BMI、聚苯胺与BMI的界面结合状态；建立了聚苯胺、铁氧体和BMI三者之间的多界面极化模型；建立了基于内聚力模型的吸波功能体/BMI复合材料力学模型，探索出了界面相的厚度、模量、泊松比和强度对于复合材料刚度、泊松比和等效模量的影响规律。.