 Assistant Professor
B.A. 1997, University of Colorado
Ph.D. 2003, Stanford University
Postdoctoral Research Associate, 2003-2006, University of Minnesota
Room: 7365a
Phone: 608-262-0421
Email: mahesh@chem.wisc.edu
Position: Assistant Professor
M. B. Runge, C. E. Lipscomb, L. Ditzler, M. K. Mahanthappa, A. V. Tivanski, and N. B. Bowden. "Investigation of the Assembly of Coil-Comb Block Copolymers in the Solid State," Macromolecules, 2008, 41, 7687-7694.
M. K. Mahanthappa, M. A. Hillmyer, and F. S. Bates. "Mechanical Consequences of Molecular Composition on Failure in Polyolefin Composites Containing Glassy, Elastomeric, and Semicrystalline Components," Macromolecules, 2008, 41, 1341-1351. M. K. Mahanthappa, L. S. Lim, M. A. Hillmyer, and F. S. Bates. "Control of Mechanical Response in Polyolefin Composites: Incorporation of Glassy, Rubbery, and Semicrystalline Components," Macromolecules, 2007, 40, 1585–1593. A. J. Meuler, M. K. Mahanthappa, M. A. Hillmyer, and F. S. Bates. "Synthesis of Monodisperse α-Hydroxy-Polystyrene in Hydrocarbon Media Using a Functional Organolithium," Macrmolecules, 2007, 40, 760–762. Mahanthappa, M. K., Bates, F. S., and Hillmyer, M. A. "Synthesis of ABA Triblock Copolymers by a Tandem ROMP-RAFT Strategy," Macromolecules, 2005, 38, 7890-7894. Koo, C. M., Wu, L., Lim, L. S., Mahanthappa, M. K., Hillmyer, M. A., and Bates, F. S. "Microstructure and Mechanical Properties of Semicrystalline-Rubbery-Semicrystalline Triblock Copolymers" Macromolecules, 2005, 38, 6090-6098. Mahanthappa, M. K., Cole, A. P., and Waymouth, R. M. "Synthesis, Structure, and Reactivity of Hydroxylaminato Alkyltitanium Complexes," Organometallics, 2004, 23, 1405-1410. Mahanthappa, M. K., Cole, A. P., and Waymouth, R. M. "Synthesis, Structure and Ethylene/α-Olefin Polymerization Reactivity of (Cyclopentadienyl)(nitroxide)titanium Complexes," Organometallics, 2004, 23, 836-845. Mahanthappa, M. K., Huang, K.-W., Cole, A. P., and Waymouth, R. M. "Synthesis and Structure of Titanium Complexes Containing TEMPO Ligands," Chem. Commun, 2002, 502-503. Mahanthappa, M. K. and Waymouth, R. M. "Titanium-Mediated Syndiospecific Styrene Polymerizations:" Role of Oxidation State," J. Am. Chem. Soc., 2001, 123, 12093-12094. Korte, B. J., Sommer, R. D., Sellers, S. P., Mahanthappa, M. K., Durfee, W. S., and Yee, G. T. "New Donors and Acceptors for Molecule-based Magnetism Research," ACS Symp. Ser., 1999, 727, 69-83.
| Research Description
Polymeric materials are economically produced from a variety of chemical feedstocks for applications ranging from commodity packaging and structural materials to value-added materials for microelectronic and biomedical applications. Copolymers, resulting from linking two or more monomer units into a single polymer chain, exhibit a variety of properties depending on the molecular structures of the monomers, the order in which they are enchained, and the manner in which the functional groups in the monomers interact to alter the solid state structure ("morphology") and bulk properties of the material. Numerous studies have established that various monomer structures and the exact copolymer sequences sensitively influence the properties and the potential applications of polymers in applications that require selective gas permeability, toughness, and mechanical strength. The discovery of copolymeric materials with new and useful properties therefore depends sensitively on the ability to synthesize polymer architectures with precise control over functional group incorporation, chain architecture, and comonomer sequences in order to control solid-state structure and to tune bulk materials properties and processabilities.
Efficient development of new and useful polymeric materials requires two synergistic skills sets:
(i) the ability to develop and to exploit new synthetic methods to produce new molecular structures with precise control over chain structure, functional group placement, and monomer sequence, and
(ii) the ability to physically characterize materials as ensembles of molecules to effectively evaluate their morphology, properties, and ultimate utility in applications.
Based on my group's unique combination of skills in synthetic methods development to make new polymer structures and in characterization of the resulting soft materials, our group synthesizes and fully characterizes new polymeric materials in order to discover new means for controlling polymer morphology to achieve unusual physical properties. In order to maximize the potential applications of these new materials, our research focuses on energy efficient ("green") syntheses amenable to large-scale production using inexpensive chemical feedstocks. Through this powerful combination of skills within my group, we rapidly identify novel materials targets and develop and optimize their flexible and scalable syntheses.
Research projects in my group focus on three significant challenges in polymer science that leverage the synthesis and characterization of new materials within the confines of a single research group:
Project Area 1. Degradable and Biodegradable Block Copolymers. Block copolymers are unique macromolecules comprised of two chemically distinct homopolymer segments that are covalently linked. Due to the chemical incompatibility of the homopolymer blocks (immiscibility), these polymers spontaneously self-assemble into a variety of well-defined structures (Figure 2) with unique physical properties. We have recently developed the syntheses of a new class of block copolymers that are expected to be (bio)degradable in the environment and in vivo. We are examining structure-property relationships therein toward the development of degradable commodity plastics, surfactants, and value-added tissue scaffolding and biomedical materials.
Project Area 2. Polydispersity effects in block copolymer phase behavior. We are probing the phase behavior of new multiblock copolymers that contain polydisperse segments to understand the implications of broadening polymer molecular weight distributions (chain length distributions) on the physics of self-assembly, processability, and properties of these materials.
Project Area 3. Approaches to linear and branched ethylene/polar monomer copolymers. We are exploring new, energy efficient metal-catalyzed reactions to produce unknown linear and branched ethylene/acrylate and ethylene/vinyl alcohol copolymers with well-defined polymer chain structures and currently inaccessible non-random sequence distributions with potentially new properties.
Each of these project areas develops and exploits new synthetic methods in organic and polymer chemistry to gain a molecular level understanding and control over polymer morphology, bulk materials properties, and polymer processabilities toward the development of new and useful commodity polymers for widespread applications.
National Science Foundation CAREER Award, 2008 3M Non-Tenured Faculty Award, 2008 Fannie and John Hertz Foundation Graduate Fellowship, 1997-2003 Boettcher Foundation Fellowship, 1993-1997 7th Place Westinghouse Science Talent Search Award, 1993.
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