Development and study of donor-acceptor Stenhouse adduct junction-functionalised block copolymers

  • Justus Wesseler

Student thesis: Doctoral Thesis


This thesis details the development of novel polymer species functionalised withdonor-acceptor Stenhouse adducts (DASAs) and the study of their light- and force responsive properties. The synthetic work conducted during this research expands the scope of possible macromolecular species accessible with DASAs embedded, providing methods for future efforts to develop sophisticated light-responsive DASA materials. The synthetic limitations of DASAs in generating novel polymer materials is discussed and solutions are demonstrated, with different approaches being critically evaluated. Amphiphilic block copolymers, both linear and graft type, were successfully functionalised with DASAs at block junctions, an entirely new concept not reported in literature thus far. Through studies of the DASAs’ photo-induced isomerisation within these new polymer environments, the possibility of altering the photochromic performances of the DASAs by virtue of having them conjugated to multiple macromolecular species is shown. Computational calculations support the notion that DASAs may undergo force-induced, cyclic-to-linear isomerisation. This is explored through the means of pulsed ultrasound of dilute solutions containing the functionalised DASA copolymers. Results indicate a propensity of DASAs degradation which manifests as scission of block copolymers at the junction or the de-grafting ofarms from their backbone. Initial efforts investigating the possibility of incorporating DASAs as crosslinker species are outlined, to incorporate DASAs in polymer networks, further expanding the scope of accessible DASA materials. Attempts of compression induced DASA ring-opening show signs of mechanophoric behaviour which warrants further quantitative investigation. Additionally, a study of DASAs functionalised polystyrene microspheres is described, where the DASAs endow the microspheres with enhanced, on-demand aqueous wettability upon irradiation. This study sets the stage for further optimisation towards solid-phase extraction or phase-transfer catalysis applications. Overall, this thesis successfully demonstrates the generationof novel DASA-based light-sensitised materials in hitherto unreported manners. The results should guide future design of light-responsive polymer materials using DASAs and provide compelling evidence of DASA mechanosensitivity.
Date of Award23 Feb 2023
Original languageEnglish
Awarding Institution
  • University Of Strathclyde
SupervisorPeter Cormack (Supervisor) & Nico Bruns (Supervisor)

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