Sakai Hio, Aoki Daisuke, Seshimo Kota, Mayumi Koichi, Nishitsuji Shotaro, Kurose Takashi, Ito Hiroshi, Otsuka Hideyuki
Department of Chemical Science and Engineering, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550, Japan.
Department of Advanced Materials Science, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 277-8561, Japan.
ACS Macro Lett. 2020 Aug 18;9(8):1108-1113. doi: 10.1021/acsmacrolett.0c00321. Epub 2020 Jul 21.
A difluorenylsuccinonitrile-(DFSN)-based linker, whose central C-C bond is readily cleaved under mechanical stress to generate a relatively stable pink radical species, was introduced into polymer networks. DFSN-based cross-linked polymers exhibit improved mechanical properties as compared to those of the corresponding covalently cross-linked polymers owing to the energy dissipation induced by cleavage of the central DFSN bond. The toughening mechanism of DFSN-based elastomers is qualitatively visualized by the intensity of the pink color and can be quantitatively characterized by electron paramagnetic resonance. These results demonstrate that the extent of DFSN cleavage is the main factor improving the mechanical properties of the polymer networks.
一种基于二芴基琥珀腈（DFSN）的连接体被引入到聚合物网络中，该连接体的中心碳 - 碳键在机械应力下易于断裂，从而产生相对稳定的粉红色自由基物种。与相应的共价交联聚合物相比，基于DFSN的交联聚合物由于中心DFSN键断裂引起的能量耗散而表现出改善的机械性能。基于DFSN的弹性体的增韧机制可以通过粉红色的强度进行定性可视化，并可以通过电子顺磁共振进行定量表征。这些结果表明，DFSN的断裂程度是改善聚合物网络机械性能的主要因素。
