基于螺旋结构的手性Schiff碱聚合物的设计合成、吸波性能和构效关系研究

Chiral stealth material as one of advanced stealth material have caused intensive concerns of the military powers of all over the word because of numerous advantages, such as cross-polarization of electromagnetic fields, adjustable hand parameters, small insensitivity to the frequency and broadband absorption and so on. In addition, Schiff base stealth material is also one of hot spots as another stealth material due to light weight, band-width, excellent absorbing properties. Thus, in the project chirality will be introduced to Schiff base stealth materials in order to obtain the stealth materials with superior absorbing properties by synergy effect. It not only has great scientific significance and wide application prospects, but also makes a greater contribution to enhance the combat capability of aviation weapon and to reduce the electromagnetic pollution to the environment..A series of chiral Schiff base polymers with helical structures will be synthesized via addition -condensation rection between a series of diamine and dicarbonyl compounds with hydroxyl, carboxyl or sulfonyl ester groups. The structures, chirality and thermal property of the polymers will be characterized by Ultraviolet visible spectrophotometer (UV-vis), Fourier transform infrared (FT-IR) spectra, Single crystal X-ray diffraction, circular dichroism spectroscopy (CD), differential thermal analysis thermogravimetry (DTA-TG). The conductivity, magnetic and absorbing properties of the polymers will be detected，and the relationship between the structure, chiral and absorbing properties of the polymers and absorbing mechanism will be studied, which lay the foundation for the further research on the chiral absorbing materials.

手性隐身材料具有电磁场可以交叉极化，手性参数可调，频率敏感性小，容易实现宽频吸收等优点，是世界军事强国研究开发的先进隐身材料之一；Schiff碱类隐身材料由于质轻、带宽、吸波性能良好而成为热点研究方向；将手性引入Schiff碱类隐身材料中以期通过两者的协同增效作用，获得性能更加优越的隐身材料，这无疑具有重要的科学意义和良好的应用前景，对增强我国航空兵器的作战能力和减少电磁波的污染做出更大贡献。.通过设计合成一系列含氧官能团取代的手性二胺和双羰基化合物，并通过它们的缩聚反应合成一系列具有螺旋结构的手性Schiff碱聚合物，利用UV-vis、FT-IR、XRD、CD和GPC、DTA-TG手段对聚合物的结构、手征特性和热性能等进行表征，检测化合物的导电性、磁性和吸波性能，并探讨这类化合物的结构、手性与吸波性能的关系及吸波机理，为进一步研究手性吸波材料奠定基础。

在国家自然科学基金的资助下，本项目利用手性单胺、二胺与单羰基或双羰基化合物反应得到了一系列具有螺旋结构的手性聚Schiff碱化合物。通过红外、质谱和核磁及凝胶色谱等手段对其结构进行了表征，利用扫描电镜或透射电镜等方法对其形貌和微观结构进行了分析，利用旋光仪检测旋光性和进行手性分析，同时测定这些聚合物及其与磁性材料复合后的复合材料的导电性能、电磁参数和吸波性能；获得了一系列在6-18GHz吸波性能好、质轻、带宽、稳定性好的手性Schiff碱聚合物复合吸波材料；初步分析了吸波性能的影响因素。