This thesis describes the synthesis of degradable materials based on functional aliphatic polycarbonates/polyesters synthesised via ring-opening copolymerisation (ROCOP) and post-polymerisation modifications. Chapter 3 details the synthesis of cationic poly(ester-b-carbonate-b-ester) via ringopening copolymerisation of CO₂ and vinyl-cyclohexene oxide (v-CHO), ringopening polymerisation (ROP) of rac-lactide, and subsequent post-polymerisation modifications of this material through a radical thiol-ene reaction and a quaternisation reaction. These cationic polymers show high surface zeta-potential (> 40 mV) and display effective antibacterial properties with killing efficiencies of > 99.9% against Gram-negative bacteria Escherichia coli. Chapter 4 describes the synthesis of amphiphilic block poly(phosphoester-b-carbonate-b-phosphoester)s using ROCOP of CO₂ and v-CHO and ROP of ethyl ethylene phosphate (EP). These amphiphilic block polymers self-assemble into either micelles or vesicles, depending on the hydrophobic/hydrophilic block ratio. The potential use of the vesicles in drug delivery is also described, and initial results detailing the enzymatic degradation of these vesicles are presented. In addition, the hydroboration-oxidation is investigated as a new post-polymerisation modification method to functionalise an alkene-containing polycarbonate, poly(vinylcyclohexene carbonate) (^VPC). The hydroxyl functionalised polycarbonate shows improved hydrophilicity and cell adhesion, compared to the unfunctionalised precursor. The side chain hydroxyl groups are then tested for making graft poly(carbonate-g-phosphoester). Chapter 5 further investigates the use of the hydroboration-oxidation reaction in functionalising poly(cyclohexadiene carbonate) (^CPC) and poly(vinylcyclohexenemaleate) (^V,MPE). A selective post-polymerisation modification is also demonstrated on a blend of ^CPC and ^VPC or ^V,MPE featuring both terminal and internal alkene groups using the hydroboration-oxidation method, where the terminal alkene groups are functionalised exclusively. Lastly, an orthogonal post-polymerisation approach is carried out on the unreacted internal alkene groups of hydroxyl-containing ^V,MPE via thiol-ene reactions to install other functional groups such as carboxyl, amine and methoxy-poly(ethylene glycol).

No / Functional, degradable polymers were synthesized via the copolymerization of vinyl acetate (VAc) and 2-methylene-1,3-dioxepane (MDO) using a macro-xanthate CTA, poly(N-vinylpyrrolidone), resulting in the formation of amphiphilic block copolymers of poly(NVP)-b-poly(MDO-co-VAc). The behavior of the block copolymers in water was investigated and resulted in the formation of self-assembled nanoparticles containing a hydrophobic core and a hydrophilic corona. The size of the resultant nanoparticles was able to be tuned with variation of the hydrophilic and hydrophobic segments of the core and corona by changing the incorporation of the macro-CTA as well as the monomer composition in the copolymers, as observed by Dynamic Light Scattering, Static Light Scattering, and Transmission Electron Microscopy analyses. The concept was further applied to a VAc derivative monomer, vinyl bromobutanoate, to incorporate further functionalities such as fluorescent dithiomaleimide groups throughout the polymer backbone using azidation and “click” chemistry as postpolymerization tools to create fluorescently labeled nanoparticles. / University of Warwick, BP, The Royal Society

Yes / Sequential ring-opening and reversible addition–fragmentation chain transfer (RAFT) polymerization was used to form a triblock copolymer of tetrahydropyran acrylate (THPA), 5-methyl-5-allyloxycarbonyl-1,3-dioxan-2-one (MAC) and L-lactide. Concurrent deprotection of the THPA block and crystallization-driven self-assembly (CDSA) was undertaken and allowed for the formation of cylindrical micelles bearing allyl handles in a short outer core segment. These handles were further functionalized by different thiols using photo-initiated thiol–ene radical reactions to demonstrate that the incorporation of an amorphous PMAC block within the core does not disrupt CDSA and can be used to load the cylindrical nanoparticles with cargo. / Royal Society (Great Britain), Engineering and Physical Sciences Research Council (EPSRC), European Research Council (ERC)