Polymerization Kinetics and Polymer Characterization by Fluorogenic Atom Transfer Radical Polymerization (ATRP)

Controlling reaction kinetics with precision is vital for tailoring polymer properties such as molecular weight and dispersity; thus, reactions which are able to control and optimize for these characteristics are becoming increasingly important. Current methods that are able to reliably and carefully monitor polymerizations involve highly specialized, costly, and low-throughput instrumentation which all sacrifice the ability to monitor reaction kinetics in real-time. As an alternative to these complex and expensive setups, fluorogenic atom transfer radical polymerization (fluorogenic ATRP) is explored as a simple and accessible method for the direct, in situ, monitoring of polymerization kinetics and for the purposes of polymer molecular weight characterization. The Cooley Group has previously demonstrated that a fluorogenic monomer probe, anthracene methacrylamide (AnMA), will yield a fluorescent polymer upon co-polymerization, even at low concentrations of this monomer. The trace incorporation of anthracene methacrylamide into a variety of preexisting reactions allows for simple fluorescence measurements to act as a non-invasive technique to monitor the degree of polymerization and polymer molecular weight. This work details the testing and efficacy of this approach through reactions which copolymerize anthracene methacrylamide (and other fluorogenic monomers) into a variety of both established and emerging ATRP reactions to understand and define parameters for the relationship between observed polymer fluorescence and polymer characteristics. Additional work is also being done to characterize the polymers formed from these reactions, and a proof-of-concept surface-initiated polymerization application has been developed and is currently the subject of ongoing experimentation.