Access to Main-Chain Photoswitching Polymers via Hydroxyl-yne Click Polymerization

Linh Duy Thai; Jochen A Kammerer; Patrick Théato; Hatice Mutlu; Christopher Barner-Kowollik

doi:10.1021/acsmacrolett.4c00216

Access to Main-Chain Photoswitching Polymers via Hydroxyl-yne Click Polymerization

ACS Macro Lett. 2024 May 16:681-687. doi: 10.1021/acsmacrolett.4c00216. Online ahead of print.

Authors

Linh Duy Thai^{1

2

3}, Jochen A Kammerer^{1

2}, Patrick Théato^{4

5}, Hatice Mutlu⁶, Christopher Barner-Kowollik^{1

2

3}

Affiliations

¹ School of Chemistry and Physics, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD 4000, Australia.
² Centre for Materials Science, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD 4000, Australia.
³ Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
⁴ Institute for Chemical Technology and Polymer Chemistry, Karlsruhe Institute of Technology (KIT), Engesser Str. 18, D-76131 Karlsruhe, Germany.
⁵ Soft Matter Synthesis Laboratory, Institute for Biological Interfaces III, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany.
⁶ Institut de Science des Matériaux de Mulhouse, UMR 7361 CNRS/Université de Haute Alsace, 15 rue Jean Starcky, Mulhouse Cedex, 68057 France.

PMID: 38755739
DOI: 10.1021/acsmacrolett.4c00216

Abstract

Main-chain stimuli-responsive polymers synthesized via polymerization techniques that do not rely on metal-based catalysis are highly desirable for economic reasons and to avoid metal-polymer interactions. Herein, we introduce a metal-free head-to-tail organobase-catalyzed hydroxyl-yne click polymerization of an AB-type monomer to realize photoswitchable polymers featuring α-bismines as main-chain repeating units. The prepared main-chain α-bisimine-based polymers show excellent photoswitching in solution. We further post-functionalize the obtained polymers with various thiol compounds via thiol-Michael reactions to significantly lower the glass transition temperature (T_g), likely to be beneficial for the photoswitching process in the solid state. Thus, the herein introduced polymerization technique not only provides metal-free access to main-chain stimuli-responsive polymers, but also allows for the flexible post-modification of the obtained polymers to generate advanced macromolecular architectures with tunable properties.