2011 Theses Doctoral

A 'Toolkit' of Small Molecules for Polymer Assembly and Post-Synthetic Modification Using 'Click' and Photoactive Chemistries

Lancaster, Jeffrey R.

Small molecules have been synthesized toward the goals of constructing and modifying polymeric materials according to simple, generalizeable, and universal processes. The prepared compounds rely upon a combination of photochemistry and the 'click' philosophy to alter the architecture, bulk properties, or surface chemistry of polymers. In Chapter 1, a review is presented that details the many implementations of the 'click' philosophy to polymer chemistry. The influence of 'click' and photochemistry upon macromolecules is discussed using a topological approach to polymer architecture. Chapter 2 details the synthesis of several second-generation homobifunctional exogenous photocrosslinkers that extend upon previous work from our group. Additionally, a first-generation crosslinker is used to core-crosslink micellar aggregates of block copolymers. Chapter 3 describes the design, synthesis, and implementation of a photoactive 'click' activator for polymer surfaces. This chapter extends the notion of a material-specific anchor from hard substrates to a range of soft polymer substrates. Chapter 4 is an inquiry into the nature of the photoreaction of a standard photoactive moiety - benzophenone - with model compounds that represent polymers in which the crosslinkers of Chapter 2 are embedded. Comparison of competitive rates of abstraction gives insight into the reactive preferences of the crosslinkers and anchors of the previous chapters. In Chapter 5 small molecules and macromonomers are described that build upon the compounds described in previous chapters which collectively form the basis of a 'toolkit' approach to polymer assembly and modification. Variations and extensions upon the 'toolkit' are detailed in order to give a sense of the future possibilities of this approach.