Photoswitchable block copolymers based on main chain α-bisimines. Issue 39 (20th September 2022)

• Record Type: Journal Article
• Authors: Thai, Linh Duy; Guimaraes, Thiago R.; Spann, Sebastian; Goldmann, Anja S.; Golberg, Dmitri; Mutlu, Hatice; Barner-Kowollik, Christopher
• Is Part Of: Polymer chemistry. Volume 13:Issue 39(2022)
• Page Start: 5625
• Page End: 5635
• Publication Date: 2022-09-20
• Subjects: Polymers -- Periodicals; Macromolecules -- Periodicals; Polymerization -- Periodicals; 547.705
• DOI: 10.1039/d2py00994c
• Languages: English
• ISSNs: 1759-9954

Abstract

Abstract : We introduce linear diblock copolymers (BCPs) consisting of readily accessable and photoswitchable α-bisimine units in the polymer backbone. Abstract : We introduce linear diblock copolymers (BCPs) consisting of readily accessable and photoswitchable α-bisimine units in the polymer backbone. The BCPs are prepared via a combination of activators regenerated by electron transfer (ARGET) atom transfer radical polymerization (ATRP) and head-to-tail acyclic diene metathesis (ADMET) polymerization. The selective head-to-tail ADMET polymerization of α-bisimine-based asymmetrical monomers in the presence of macro-chain stoppers allows for the construction of well-defined block copolymers. Acrylate-endcapped polystyrenes synthesized from ARGET ATRP and commercial poly(ethylene glycol) methyl ether acrylate were used as macro-chain stoppers. 1 H NMR spectroscopy and Size-Exclusion Chromatography (SEC) confirmed the light-responsive properties of the resulting block copolymers (BCPs) in solution. An unambigeous reversible ( Z, Z )/( E, E )-isomerization of the α-bisimines was observed for PS- and PEG-based BCPs upon UV irradiation ( λ max = 254 nm). The advanced synthetic approach paves the way towards the preparation of efficient light-responsive materials, where in-chain morphological changes are required.