光致形变含偶氮超支化聚酰亚胺的制备与性能研究

In recent years, photomechanical effects in azobenzene-containing polymeric materials have attracted considerable attention because the photomechanical response of these materials can be considered as an energy transduction process, which converts light stimulus input into mechanical output. Among the azobenzene-containing photomechanical polymeric materials, azobenzene-containing polyimides have attracted considerable attention in preparation of photodeformable materials due to their high performance characteristics. However, the study of photodeformable azobenzene-containing polyimides is still in infancy, rational design to enhance the photomechanical response speed is still worthy of studying，and the structures of the polymers also need to be optimized. Photomechanical response speed is an important indicator of the photodeformable materials. In this project, by introducing azobenzene chromophores to hyperbranched polyimides, the photodeformable materials with better photomechanical response speed will be designed and developed. By studying the influence of the linear lengths of the hyperbranched polymers on the photodeformable behavior and mechanical properties of the materials, the optimal structure of the polymers was determinied. By designing and synthesizing monomers with different structures, the influence of the structures of monomers on the photodeformable behavior and performance of azobenzene-containing hyperbranched polyimides was investigated. The influence of temperature and crosslink on the photodeformable behavior and performance of the materials was also investigated. This work can provide the theoretical basis for the application of azobenzene-containing polyimides in the field of photodeformable materials.

光致形变偶氮聚合物因其能将光能转化为机械能，在光驱动微执行器等领域具有潜在的应用价值而备受关注。含偶氮聚酰亚胺因其优异的综合性能而成为光致形变材料新的研究热点。光致形变含偶氮聚酰亚胺材料研究仍处于起步阶段，其光响应速率仍需提高。将超支化结构引入到含偶氮聚酰亚胺可以增大聚合物自由体积，从而提高其光响应速率。另一方面，如何提高超支化聚酰亚胺的机械性能也是亟待解决的科学问题。本项目拟将含偶氮超支化聚酰亚胺应用于光致形变材料的制备，以提高其光响应速率。通过改变超支化聚合物中线性部分结构长度改善含偶氮超支化聚酰亚胺的机械性能。通过研究含偶氮超支化聚酰亚胺中线性结构长度、偶氮二胺单体链柔性、二酐单体结构、交联度和温度对其光致形变性能、机械性能和热性能影响，揭示含偶氮超支化聚酰亚胺光致形变材料的构筑规律。期待本项目的研究工作能够为含偶氮超支化聚酰亚胺在光致形变领域的应用提供理论和实验基础。

光致形变偶氮聚合物因其能将光能转化为机械能而备受关注。含偶氮聚酰亚胺材料由于自身优异的热稳定性可以在高温或特种环境下使用。然而，线型聚酰亚胺材料由于分子链缠结和堆积，导致其光致形变速率较慢。本项目将含偶氮超支化聚酰亚胺应用于光致形变高分子材料的制备，以提高含偶氮聚酰亚胺光致形变速率。通过研究超支化偶氮聚酰亚胺中线型结构长度、链柔性、二酐单体结构、温度和激发波长对其光致形变行为的影响，揭示含偶氮超支化聚酰亚胺光致形变材料的构筑规律。具体内容如下：（1）通过调控单体投料比，设计合成了含有不同长度线型结构的含偶氮超支化聚酰亚胺材料。光致形变行为研究结果表明，随着线型结构长度的降低，聚合物的光致形变速率变快。（2）通过调节三胺单体类型，设计合成了具有不同柔性支化结构的含偶氮超支化聚酰亚胺材料。光致形变行为研究结果表明，随着链柔性的增加，聚合物的光致形变速率相应变快。（3）以不同结构二酐为单体，制备了结构不同的含偶氮超支化聚酰亚胺聚合物。光致形变行为研究结果表明，扭曲刚性联二萘基团的引入，增大了聚合物的自由体积，从而提高了聚合物的光致形变速率。聚合物在442 nm非偏振激光照射下的光致形变速率大于在532 nm非偏振激光照射下的光致形变速率。 （4）探索性地研究了含偶氮聚芳醚材料在光致形变高分子材料领域的应用。随着偶氮基团含量的提高，聚合物的最大弯曲角度和光致形变速率相应变大。聚合物在442 nm偏振激光照射下的光致形变速率和角度均大于在532 nm偏振激光照射下的光致形变速率和角度。本项目的研究成果能够为含偶氮超支化聚酰亚胺的制备及其在光致形变领域应用提供理论基础和实验基础，为新型光致形变高性能含偶氮聚合物的设计和研究提供新的思路。