The Synthesis and Application of Hyperbranched Copolymers

Incorporation of comonomers into hyperbranched poly(3,5-diacetoxybenzoic acid) is explored in this thesis. Hyperbranched polymers with up to 20% of comonomers retained their dendritic properties and physical behaviour. These findings were then applied to study the application of hyperbranched copolymer as catalyst and lightharvesting models. Chapter 2 reports the development of a simple one-pot methodology for the functionalisation of a hyperbranched copolymer. This was used to prepare HBPs with multiple peripheral units. These units significantly increased the solubility, which enabled the hyperbranched copolymer to be used to study binding and catalysis in a range of solvents. Initial binding experiments in toluene and chloroform showed there was a steric barrier, which might be exploited in terms of catalysis. However, all HBP catalysed reactions in all the solvents performed identically to those performed in the control reactions. Techniques developed in chapter 2 were used in chapter 3 in an attempt to prepare a photosynthetic model for possible application for light harvesting. Incorporation of multiple ligand functionalities into the polymer was achieved, and these need to bind a number of porphyrin units. Binding constants were 1 x 103 M-1 and 1 x 105 M-1 for a monomeric porphyrin and a dimeric porphyrin respectively. The position of the ligands and the number of ligands were confirmed using NMR and UV titrations. Moreover, a self-assembly process led to the formation of a multi-porphyrin array, which was confirmed via diffusion NMR and DLS