主链含脂肪/脂环聚酰亚胺（PI）薄膜由于高透明性、低介电、易加工等优点，显示出应用于柔性电子器件的巨大潜力。因部分刚性分子链被柔性脂肪/脂环族分子链取代，主链含脂肪/脂环PI薄膜耐热性与力学性能等有所下降。仅通过PI分子主链结构设计与调整，要实现PI薄膜各性能优化仍具有挑战。本项目拟从PI薄膜加工角度出发，揭示主链含脂肪/脂环PI拉伸过程中纳微结构演变机制，实现其性能调控。拟采用原位在线检测技术（同步辐射红外光谱与X射线散射搭配单轴与双轴拉伸仪）记录主链含脂肪/脂环的PI在拉伸场下分子链取向-松弛状态、构象有序、取向（晶体）结构的形成过程，研究拉伸场下PI纳微结构对光学性能、热稳定性与力学性能等的影响机制，阐明PI纳微结构与宏观性能的定量关系，形成PI分子链结构-成型加工-聚集态结构-性能一体化新认识，实现PI薄膜性能在加工中的定向调控，为柔性电子器件用高性能PI薄膜制备奠定理论基础。

Polyimides (PIs) containing aliphatic/alicyclic segments in the main chains have shown great potential in flexible electronic devices, due to their high transparency, low dielectric and easy processing. The heat resistance and mechanical properties of this kind of PIs are decreased, because some rigid molecular chain segments are replaced by the flexible aliphatic/alicyclic molecular chain segments. It is still a challenge to optimize all the performance of PI membranes only through the structural design and adjustment of the main chains of PIs. This proposal, from the perspective of PI membranes processing, will reveal the nano- and micro-structures’ evolution mechanism of PIs containing aliphatic/alicyclic segments in the main chains during the stretching process, and realize the manipulation of their performance. In situ online detection technology (synchrotron radiation infrared spectra and X-ray scattering equipped with uniaxial and biaxial tensile tester) will be adopted to record the formation process of molecular orientation- relaxation state, conformation ordering, oriented (crystals) structures during stretching, study the effect of nano- and micro-structures on the final optical performance, thermal stability and mechanical properties of PI, clarify the quantitative relationship between the nano- and micro-structures and properties, form the new understanding of the PI molecular chain structure - processing – the aggregation structure – performance, realize the “structuring processing” of PI membrane properties. These work will lay a theoretical foundation for the preparation of high-performance PI membranes that used in the flexible electronic devices.