Circular Upcycling of Bottlebrush Thermosets

Autor: Daixuan Zhang, Foad Vashahi, Erfan Dashtimoghadam, Xiaobo Hu, Claire J. Wang, Jessica Garcia, Aleksandra V. Bystrova, Mohammad Vatankhah‐Varnoosfaderani, Frank A. Leibfarth, Sergei S. Sheiko
Rok vydání: 2023
Předmět:
Zdroj: Angewandte Chemie. 135
ISSN: 1521-3757
0044-8249
DOI: 10.1002/ange.202217941
Popis: The inability to re-process thermosets hinders their utility and sustainability. An ideal material should be able to combine both closed-loop recycling and upcycling capabilities, thus providing a circular materials platform. This concept is realized in bottlebrush thermosets through dynamic covalent crosslinking. The polydimethylsiloxane networks described herein use thermoreversible Diels-Alder cycloadditions to demonstrate their ability to both reversibly disassemble into a polymer melt and/or reconfigure on-demand to an elastomer of either lower or higher stiffness. To accomplish these functions, the crosslink density was tuned by loading the functionalized networks with a controlled fraction of dormant crosslinkers and crosslinker scavengers, such as furan-capped bis-maleimide and anthracene, respectively. The resulting modulus variations precisely followed the stoichiometry of activated furan and maleimide moieties, demonstrating the lack of deleterious side reactions during reprocessing. The presented circularity concept is independent from the backbone or side chain chemistry, making it potentially applicable to a wide range of brush-like polymers.
Databáze: OpenAIRE
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