| Summary: | This thesis explores the use of bromo and thio maleimide functional groups in polymer chemistry. The reactivity of bromomaleimide groups towards thiols is exploited as a new and efficient post-polymerisation modification reaction, while the fluorescence of the dithiomaleimide (DTM) products is utilised for labelling of polymers and polymer nanoparticles. Chapter 1 gives an introduction to ways in which control over free radical polymerisation can be achieved using reversible-deactivation mechanisms. The incorporation of functionality into polymers, and the synthesis of polymer nanoparticles is also discussed, leading to a review of the different strategies for fabrication of fluorescent polymer nanoparticles. In Chapter 2 novel reversible addition-fragmentation chain transfer (RAFT) agents are developed with the aim of introducing monobromomaleimide (MBM) or dibromomaleimide (DBM) as a polymer end-group via RAFT. In Chapter 3 the fluorescent properties of the DTM group are first explored, then a novel RAFT agent/ring-opening polymerisation initiator is used for site-specific introduction of DTM fluorophores into linear polymers. Site-specific introduction of DTM groups by post-polymerisation functionalisation reaction of DBM-terminated polymers (synthesised in Chapter 2) with thiols is also developed. In Chapter 4 novel DTM and DBM-functional vinyl monomers are synthesised, and their RAFT polymerisation with non-functional comonomers is used to incorporate DTM and DBM functionality along polymer backbones. Post-polymerisation functionalisation of these DBM-functional polymers with thiols is also demonstrated. In Chapter 5 fluorescently-labelled polymer nanoparticles containing DTM fluorophores are synthesised, using the DTM-functional RAFT agent developed in Chapter 3, and DTM-functional monomers developed in Chapter 4. Nanoparticles are fabricated by block copolymer self-assembly and emulsion polymerisation. These fluorescent nanoparticles are analysed by steady-state and time-resolved fluorescence spectroscopy to assess their utility as contrast agents. Chapter 6 summarises RAFT polymerisation data from Chapters 2, 3 and 4 to assess the extent to which the DBM and DTM groups interfere in RAFT polymerisation, and the mechanism by which this may occur.
|
|---|
