Professor Michael Shaver
The Shaver group's research interests bridge a number of disciplines within chemistry, incorporating aspects of green chemistry, organometallics, materials science and organic synthesis to the field of polymer chemistry. Our group's focus is on controlling the synthesis of polymers in order to tune the properties of the resultant materials. To do this we depend upon metal complexes to mediate controlled radical polymerizations and ring opening polymerization. Unifying these projects is the theme of catalyst design. Ligand frameworks allow us to design metal complexes that are able to control various aspects of polymerization reactions including molecular weight, polydispersity, stereospecificity and structure. These molecular properties impart control over the materials properties, allowing us to tune our polymers to specific applications. Our current group focus lies in three areas:
- IRON IN ATRP. We have developed a new family of iron complexes for the atom transfer radical polymerization (ATRP) of an array of monomers. These catalysts are the fastest iron-based system for controlled radical polymerization and rival some of the top copper catalysts reported and importantly produce brilliant white plastics using a benign catalyst.
- MICROSTRUCTURE AND MACROSTRUCUTRE CONTROL. We have recognized that, while the stereocontrolled synthesis of linear aliphatic polyesters is well studied, we can use stereochemistry to tune the properties of larger macrostructures, altering their thermal properties (Tg, Tc, Tm, Td), degradation and gelation.
- BIODEGRADABLE POLYMER SYNTHESIS. We design catalysts to control ring-opening polymerizations and use these to prepare homo and copolymers of a variety of cyclic ester monomers. Catalyst design influences rates, relative reactivities and polymer tacticity as well as opening up immortal polymerization mechanisms.
- Wang, M.; Nudelman, F.; Matthes, R.; Shaver, M. P.* “Frustrated Lewis Pair Polymers as Responsive Self-Healing Gels” J. Am. Chem. Soc. 2017, 139, 14232.
- McClements, J.; Buffone, C.; Shaver, M. P.; Sefiane, K.; Koutsos, V.* “Poly(styrene-co-butadiene) random copolymer thin films and nanostructures on a mica surface: morphology and contact angles of nanodroplets” Soft Matter 2017, 13, 6152.
- Cairns, S. A.; Schultheissa, A.; Shaver, M. P.* “A broad scope of aliphatic polyesters prepared by elimination of small molecules from sustainable 1,3-dioxolan-4-ones” Polym. Chem. 2017, 8, 2990.
- Sinclair, F.; Chen, L.; Greenland, B. W.; Shaver, M. P.* “Installing Multiple Functional Groups on Biodegradable Polyesters via Post-Polymerization Olefin Cross Metathesis” Macromolecules 2016, 49, 6826.
- Zhu, K.; Shaver, M. P.*; Thomas, S. P.* “Chemoselective nitro reduction and hydroamination using a single iron catalyst” Chemical Science 2016, 7, 3031.