Macromolecular Chemistry, Division of Technical and Macromolecular Chemistry, Institute of Chemistry, Faculty of Natural Science II (Chemistry, Physics, and Mathematics), Martin Luther University Halle-Wittenberg, Von-Danckelmann-Platz 4, Halle, D-06120, Germany.
Macromol Rapid Commun. 2018 Nov;39(22):e1800376. doi: 10.1002/marc.201800376. Epub 2018 Aug 12.
Strategies for visualizing stress within polymeric materials are of growing interest during the past decade. In this paper, stress-sensing materials, triggered by a mechanoresponsive catalytic system based on latent copper(I)bis(N-heterocyclic carbene) mechanophores, are reported, which can be activated by compression force to trigger a fluorogenic copper(I)-catalyzed alkyne/azide "click" cycloaddition reaction, activating a fluorescent dye useful for stress-sensing applications in bulk polymeric materials. The focus is placed on the polymeric architecture, which is responsible for an efficient stress transmission, revealing the greatest activation for network-based mechanocatalysts, observing "click" conversions up to 44%, while chain-extended and linear mechanocatalysts activate either in a less efficient manner or are not completely latent in the initial state. The developed catalysts enable "irreversible" mechanochromic systems for stress-sensing devices.
在过去十年中，人们对聚合物材料内的应力可视化策略越来越感兴趣。本文报道了一种基于潜伏铜（I）双（N-杂环卡宾）机械敏感前体的机械响应催化体系的应力感应材料，它可以通过压缩力激活，触发荧光铜（I）-催化的炔/叠氮“点击”环加成反应，激活用于块状聚合物材料中的应力感应应用的荧光染料。重点放在聚合物结构上，它负责有效地传递应力，对于基于网络的机械催化剂显示出最大的激活作用，观察到“点击”转化率高达 44%，而链扩展和线性机械催化剂则以效率较低的方式激活，或者在初始状态下不完全潜伏。所开发的催化剂为用于应力感应装置的“不可逆”机械变色系统提供了可能。
