Baczkowski Matthew L, Wang David H, Lee Deborah H, Lee Kyung Min, Smith Matthew L, White Timothy J, Tan Loon-Seng
Air Force Research Laboratory, Materials & Manufacturing Directorate, Wright-Patterson Air Force Base, Ohio 45433-7750, United States.
Department of Engineering, Hope College, Holland, Michigan 49423, United States.
ACS Macro Lett. 2017 Dec 19;6(12):1432-1437. doi: 10.1021/acsmacrolett.7b00854. Epub 2017 Dec 6.
Photomechanical effects realized in azobenzene-functionalized polyimides have shown large deformation and an exceptional increase in photogenerated force output. Here, we synthesize and characterize the photomechanical output of a series of linear polyimide materials prepared with a bulky substituent, incorporated via the development of a new bis(azobenzene-diamine) monomer containing a 9,9-diphenylfluorene cardo structure (azoCBODA). All six azoCBODA-containing polyimides are amorphous and exhibit high glass transition temperatures () ranging from 298 to 358 °C, storage moduli ranging from 2.27 to 3.81 GPa (at 30 °C), and good thermal stability. The magnitude of the photoinduced mechanical response of the azobenzene-functionalized polyimide is correlated to the rotational freedom of the polyimide chains (resulting in extensive segmental mobility) and fractional free volume (FFV > 0.1).
在偶氮苯功能化聚酰亚胺中实现的光机械效应已显示出大变形和光生力输出的异常增加。在此，我们合成并表征了一系列线性聚酰亚胺材料的光机械输出，这些材料是通过开发一种含有9,9-二苯基芴咔唑结构的新型双（偶氮苯二胺）单体（azoCBODA）制备的，其中引入了庞大的取代基。所有六种含azoCBODA的聚酰亚胺都是非晶态的，具有298至358°C的高玻璃化转变温度（）、30°C下2.27至3.81 GPa的储能模量以及良好的热稳定性。偶氮苯功能化聚酰亚胺的光致机械响应幅度与聚酰亚胺链的旋转自由度（导致广泛的链段迁移率）和分数自由体积（FFV > 0.1）相关。
