Lewis acidic metal complexes with polydentate ligands for the preparation of biorenewable polymers
Gamboa Martinez, Sergio Aaron
Gamboa, Sergio Aaron M.
Martinez, Sergio Aaron Gamboa
Due to the ever increasing necessity to reduce our dependence on fossil fuels as feedstocks for polymeric materials, the work presented herein describes the investigation of new metal complexes as initiators for the formation of polyesters and polycarbonates from renewable monomers. These polymers are regarded as biodegradable and have the properties required to replace traditional plastics in applications such as food packaging, electronic devices, and medical biomaterials. Chapter one introduces previous literature relevant to the research on which this study focuses; ligands based on alkoxides, phosphine oxides and N-heterocyclic carbenes with alkoxide or amino pendant groups, as well as the metal complexes in which they are used. Current methods of polymerisation and copolymerisation and the initiators utilised are also examined. Chapter two contains the design and synthesis of [M(LR n)]m metal complexes where LR is [(R)2P(O)CH2CH(tBu)O]– and R is Ph or tBu. Divalent metal centres such as CoII and ZnII have been used for the formation of the studied compounds. Studies on their reactivity as initiators for polymerisations are also described. Chapter three presents the utilisation of di- and tridentate ligands, with one or two NHC species respectively, for the synthesis of [Mx(LY n)], where M is CuI, ZnII or TiIII and LY is an alkoxy-tethered NHC species or a ‘CNC’ tridentate ligands with an amino derivative as bridge. Their reactivity and ability to act as initiators for polymerisation reactions was also examined. Chapter four comprises overall conclusions of this work and the impact of these investigations. Chapter five outlines the experimental details and data for the compounds presented.