Photoinduced Motions of Thermoplastic Polyurethanes Containing Azobenzene Moieties in Main Chains
Photoinduced Motions of Thermoplastic Polyurethanes Containing Azobenzene Moieties in Main Chains
复制标题
主链含偶氮苯部分的热塑性聚氨酯的光致运动
DOI：
10.1021/acs.macromol.1c01827
复制
发表时间：
2022
期刊：
影响因子：
5.5
通讯作者：
Ikeda Tomiki
中科院分区：
文献类型：
--
作者：
Ube Toru;Nakayama Romu;Ikeda Tomiki
合成了主链含偶氮苯基团的热塑性聚氨酯，并对其相变性能、微观结构和光诱导变形行为进行了表征。与传统的由化学交联网络组成的光移动材料不同，熔融法和溶液处理方法都可以制备具有玻璃性质的光移动薄膜。在玻璃化转变温度以上加热时，偶氮苯基团的排列和宏观形状受外力控制，并通过氢键作用形成物理交联键而稳定。单轴取向的偶氮苯薄膜在紫外光和可见光照射下呈现可逆弯曲，可重复100次。本体系中的物理交联物可以替代光可移动聚合物材料中的共价交联物，以优异的加工性扩大设计的多样性。
Thermoplastic polyurethane containing azobenzene moieties in main chains was developed for photomobile materials capable of reversible photoactuation and shape programming, and was characterized for phase transition properties, microstructures, and photoinduced deformation behaviors. Photomobile films with glassy nature could be fabricated using both melt- and solution-processing methods, in contrast with conventional photomobile materials consisting of chemically cross-linked networks. The alignment of azobenzene moieties and macroscopic shapes in the initial states were controlled by external force under heating above glass transition temperature, which were stabilized by the formation of physical cross-links through hydrogen bonding interactions. The films with uniaxial alignment of azobenzene moieties showed reversible bending upon irradiation with UV and visible light, which could be repeated for 100 cycles. Physical cross-links in the present system can be an alternative for covalent cross-links in photomobile polymer materials, expanding the variety of designs with superior processability.