Synthesis and properties of novel polyester-based materials

Polyester-based materials have received significant attention from the scientific com-munity for a plethora of applications. This thesis investigated the synthesis and properties of novel polyester-based materials synthesised by spontaneous zwitterionic co-polymerisation (SZWIP) and melt polycondensation. The synthesis of N-acylated poly(aminoester) (NPAE) macromonomers by SZWIP of cyclic imino ethers (CIEs) and acrylic acid (AA) was investigated in Chapter 2, revealing the limited effect of different reaction conditions, but interestingly demonstrated a facile way to tune the ω-end groups on the NPAE macromonomers. A post-mortem ESI MS/MS study on a small library of NPAE macromonomers was con-ducted in Chapter 3 to investigate the microstructures formed during SZWIP of CIEs and AA. This demonstrated the presence of homopropagation of CIEs as a side reaction to the alternating copolymerisation of the CIEs with AA and led to an extended mechanism for SZWIP. Next, the synthesis of well-defined comb polymers by aqueous redox-initiated RAFT polymerisation of these NPAE macromonomers was investigated in Chapter 4. The resulting comb polymers showed a dual stimuli-responsive behaviour in aqueous solution with a pH-dependant LCST behaviour. Furthermore, the efficient post-polymerisation functionalisation with model amines was demonstrated. Chapter 5 discusses early investigations into the potential of these comb polymers for biomedical applications, demonstrating the absence of cytotoxicity and haemolysis, their cellular uptake and low-fouling behaviour, amongst others. Finally, Chapters 6 and 7 discuss the synthesis of branched polyesters and poly(ester amide)s by melt polycondensation of safe and renewable materials, focussing on citric acid and gluconolactone. The simple tuneability of the glass transition temperatures of the resulting polymers through variation of reaction conditions and co-monomers was demonstrated, leading to new insights in monomer structure-thermal property relationships.