Synthesis and characterization of novel cyclic polymer architectures and potential applications
Description
Nanoscale control of polymer architecture has been a goal of polymer scientists for quite some time since it was first discovered that a polymer's properties are intrinsically related to its architecture. Cyclic polymers represent a class of understudied polymer architecture mainly due to the synthetic challenges associated with their synthesis. Within this dissertation, we report a method for the synthesis of cyclic polymers in exceptionally high purity and yield. This process relies on the preparation of well-defined linear polymer precursors by Atom Transfer Radical Polymerization (ATRP) and the high efficiency of the 1,3-Huisgen cycloaddition reaction between a terminal alkyne and azide termed 'click' chemistry. Optimization of this technique as well as full characterization of the resultant cyclic polymers is demonstrated in Chapter 2 Also presented within is the synthesis and characterization of two novel cyclic polymer architectures. Using functionalized cyclic polymers synthesized by the aforementioned route as a scaffold for further functionalization, the synthesis of cyclic dendronized polymers via both 'graft from' and 'graft to' techniques is studied in Chapter 3. The 'graft to' route showed extremely high coupling efficiencies. Highlighted is the ability of water-soluble high generation cyclic dendronized polymers to encapsulate a non-polar guest in aqueous environments by UV-Vis studies In a similar fashion, the synthesis of cyclic amphiphilic homopolymers, polymers in which each repeat unit contains an amphiphilic unit, is also presented in Chapter 4. Additionally, the ability of these materials to assist the solvation of rose bengal dye in a non-polar environment is proven Finally, Chapter 5 describes initial results towards extension of the ATRP/ 'click' cyclization route for the synthesis of multi-cyclic structures (globes). These methodology studies focus on the coupling of A x polymers with 'x' number of arms with Bx capping agents to synthesize 'X' multi-arm globes. Initial results prove the viability of this method for further study