Synthesis of polyester dendrimers
Dendrimers are a fairly new class of macromolecule. They have many potential uses including use in surface coatings and as host molecules. There are two main methods available for constructing dendrimers, the convergent approach and the divergent approach. In this thesis dendrimers were synthesised using the divergent approach. In chapter one our original aim was to synthesise dendrimers based on bicine, but there were complications involved in synthesis and storage of the monomer. However, it was possible to make a iminium salt using bicine as the starting material, which was reacted with various nucleophiles. With 2,2-bishydroxymethylpropionic acid it was possible to produce a generation one protected dendrimer, but deprotection could not be achieved. In the third chapter the syntheses of dendrimers based on 4,4-bis(4- hydroxyphenyl)valeric acid are described. Dendrimers were successfully synthesised up to and including generation two. These were made using various esterification methods. Chapter four describes the synthesis of functionalised dendrimers. Generation one deprotected dendrimers were reacted with a variety of reagents to produce pent-4-enoyl, urethane and lineoyl functionalised dendrimers. Chapter five describes the analysis of dendrimers using MALDI-MS. For every dendrimer synthesis molecular weights were obtained well within the boundaries of experimental error. It was also shown how preparation time and laser power can affect the spectra obtained.