The use of living polymerization methods for the synthesis of dendritic macromolecules

The development of living polymerization techniques has allowed for unprecedented control in the synthesis of macromolecular architectures. Highly branched polymers, such as dendrimers, have attracted attention in part due to their unusual properties. The aim of this thesis is to use living polymerization methods for the rapid and easy synthesis of new well-defined dendritic polymers.; Dendritic-linear block copolymers have been prepared in a one pot procedure using dendritic initiators in the metal catalyzed and nitroxide mediated "living" free radical polymerization of vinyl monomers. Copolymers of well-defined molecular weights and low polydispersities were obtained. Their structure was confirmed using standard chromatographic and spectroscopic techniques. The block copolymers could be readily functionalized either at the surface of dendritic block or in the linear block, leading to novel copolymers that were difficult to prepare by other methods. Some of the block copolymers exhibited interesting micellar properties.; The syntheses of dendritic-(linear polystyrene)-dendritic triblock copolymers utilizing discrete unimolecular dendritic-nitroxide initiators have been investigated. Preliminary results indicate that the desired copolymer is obtained as part of a more complicated mixture. Further analysis, separation and optimization is currently in progress.; A novel approach to the synthesis of hyperbranched polymers was developed in our laboratories: the Self-Condensing Vinyl Polymerization (SCVP). This concept was applied to the living cationic polymerization of vinyl ethers. The SCVP of one monomer was examined in great detail. Considerable side-reactions were observed under most reaction conditions leading to degradation of the polymer and poor control of the end-group functionality. Molecular weights were also limited. Viscometric analyses indicated that a branched polymer was indeed obtained but the degree of branching could not be accurately determined. The syntheses of many other vinyl ether monomers suitable for the SCVP are described.