Open AccessAutonomous Visualization of Damage in Polymers by Metal‐Free Polymerizations of Microencapsulated Activated Alkynes
Author(s) -
Han Ting,
Chen Shusheng,
Wang Xinnan,
Fu Xinyao,
Wen Haifei,
Wang Zaiyu,
Wang Dong,
Qin Anjun,
Yang Jinglei,
Tang Ben Zhong
Publication year - 2022
Publication title -
advanced science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.388
H-Index - 100
ISSN - 2198-3844
DOI - 10.1002/advs.202105395
Subject(s) - dabco , polymer , monomer , polymerization , materials science , octane , alkyne , catalysis , polyurethane , polymer chemistry , chemical engineering , chemistry , organic chemistry , composite material , engineering
The development of autonomous materials with desired performance and built‐in visualizable sensing units is of great academic and industrial significance. Although a wide range of damage indication methods have been reported, the “turn‐on” sensing mechanism by damaging events based on microcapsule systems, especially those relying on chemical reactions to elicit a chromogenic response, are still very limited. Herein, a facile and metal‐free polymerization route with an interesting reaction‐induced coloration effect is demonstrated. Under the catalysis of 1,4‐diazabicyclo[2.2.2]octane (DABCO), the polymerizations of difunctional or trifunctional activated alkynes proceed very quickly at 0 °C in air. A series of polymers composed of stereoregular enyne structure (major unit) and divinyl ether structure (minor unit) are obtained. Both the catalyst and monomers are colorless while the polymerized products are deep‐colored. This process can be applied for the damage visualization of polymers using the microencapsulation technique. Microcapsules containing the reactive alkyne monomer are prepared and mixed in a DABCO‐dispersed polymer film. Both the external and internal damage regions of this composite film can be readily visualized once the reaction is initiated from the ruptured microcapsules. Moreover, the newly formed polymer automatically seals the cracks with an additional protection function.