Kato Sota, Furukawa Shigeki, Aoki Daisuke, Goseki Raita, Oikawa Kazusato, Tsuchiya Kousuke, Shimada Naohiko, Maruyama Atsushi, Numata Keiji, Otsuka Hideyuki
Department of Chemical Science and Engineering, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8550, Japan.
Biomacromolecules Research Team, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.
Nat Commun. 2021 Jan 5;12(1):126. doi: 10.1038/s41467-020-20366-y.
The growth of lamellar crystals has been studied in particular for spherulites in polymeric materials. Even though such spherulitic structures and their growth are of crucial importance for the mechanical and optical properties of the resulting polymeric materials, several issues regarding the residual stress remain unresolved in the wider context of crystal growth. To gain further insight into micro-mechanical forces during the crystallization process of lamellar crystals in polymeric materials, herein, we introduce tetraarylsuccinonitrile (TASN), which generates relatively stable radicals with yellow fluorescence upon homolytic cleavage at the central C-C bond in response to mechanical stress, into crystalline polymers. The obtained crystalline polymers with TASN at the center of the polymer chain allow not only to visualize the stress arising from micro-mechanical forces during polymer crystallization via fluorescence microscopy but also to evaluate the micro-mechanical forces upon growing polymer lamellar crystals by electron paramagnetic resonance, which is able to detect the radicals generated during polymer crystallization.
特别是在聚合物材料中的球晶方面，已经对片晶的生长进行了研究。尽管这种球晶结构及其生长对于所得聚合物材料的机械和光学性能至关重要，但在晶体生长的更广泛背景下，关于残余应力的几个问题仍未得到解决。为了进一步深入了解聚合物材料中片晶结晶过程中的微机械力，在此，我们将四芳基琥珀腈（TASN）引入结晶聚合物中，TASN在响应机械应力时，在中心C-C键处发生均裂会产生具有黄色荧光的相对稳定的自由基。所得到的聚合物链中心带有TASN的结晶聚合物，不仅能够通过荧光显微镜观察聚合物结晶过程中微机械力产生的应力，还能够通过电子顺磁共振评估聚合物片晶生长时的微机械力，电子顺磁共振能够检测聚合物结晶过程中产生的自由基。
