Department Web-Page

Dr. Justin G Kennemur
Faculty

Dr. Justin G Kennemur

Assistant Professor

Ph.D. Chemistry - North Carolina State University (2010)

Contact Information
Email:
kennemur@chem.fsu.edu
Office:
2005 CSL 850.644.3875
Lab:
2301 CSL
Programs of Research
 Materials
 Organic
 Physical
Research Website
Research Specialities
Chemistry of Materials, Environment and Energy, Nanoscience, Synthesis and Catalysis

Research Interest

Our research is highly interdisciplinary and relies on organic synthesis, polymer synthesis, organometallic catalysis, analysis of macromolecular structure, and polymer physics / engineering to probe material function. Specific areas of interest include:

Precision Polyolefins and Elastomers

Polymeric microstructures with specific functionalities placed at a precise periodicity along the chain can offer markedly advanced and well-defined properties. A portion of our research is aimed at designing new precision polymers from the ring opening metathesis polymerization (ROMP) of low-strain cyclopentenes. This low-strain makes polymerization of these monomers synthetically challenging and we are leveraging basic equilibrium thermodynamics to produce these materials with high monomer conversion, predictable molar mass, and low dispersity. This success has opened the door to exploration of a variety of materials with branch points spaced exactly five carbons apart; opening a new materials landscape over the more common two-carbon periodicity of typical polyolefins.


Block Copolymer Self-Assembly

Block copolymers contain two or more chemically distinct polymer segments that are covalently attached at one end. If the two segments are incompatible, (e.g. one is hydrophobic and the other hydrophilic) the segments want to completely phase separate but cannot due to their covalent attachment. A compromise between the thermodynamic desire to fully separate and the entropic penalty to do so, results in microphase separation or the formation of periodic nanostructures densely populated in either segment. The size and morphology of these structures can be controlled by the size of each polymer segment. Our research is exploring new avenues of this self-assembly process by combining block segments with functional and dynamic properties, such as poly(vinylpyridines). These systems open the door unique applications in nanotechnology.


Stereochemical Effects in Sustainable Polymers

Advancements in biomass refinement and fermentation continue to expand the scope of value-added chemicals meeting the versatility, availability, and commodity production required to alleviate reliance on petroleum-derived feedstocks. Due to their natural origin, many sustainable "green" chemicals, such as sugars, feature complex chirality which underpin many important properties and functions in their original environmental design. This is unlike most petroleum derived precursors which are largely achiral and often require laborious synthetic efforts or advanced catalysts to produce a preferred chirality (or tacticity). Chirality in biomacromolecules, such as proteins, is deliberate and serves many advanced functions in from chemical sensing and expression to mechanical support and actuation. Therefore judicious translation of this chirality into new synthetic materials appears destined to provide a variety of desired properties and opportunistic applications for sustainable polymers. Our research aims to couple the inherent chirality supplied by biomass with synthetic polymer design strategies as a tool to explore new macromolecular assemblies and enhance properties through stereochemical effects.

Publications

Kennemur, J. G. "Poly(vinylpyridine) Segments in Block Copolymers: Synthesis, Self-Assembly, and Versatility" Macromolecules 2019 link
Neary, W. J.; Kennemur, J. G. "Polypentenamer Renaissance: Challenges and Opportunities" ACS Macro Lett. 2019, 8, pp.46 - 56. link
Neary, W. J.; Kennemur, J. G. "Well-Defined and Precision-Grafted Bottlebrush Polypentenamers from Variable Temperature ROMP and ATRP" ACS Macro Lett. 2019, 8, pp.46 - 56. link
Kieber III, R. J.; Silver, S. A.; Kennemur, J. G. “Stereochemical effects on the mechanical and viscoelastic properties of renewable polyurethanes derived from isohexides and hydroxymethylfurfural” Polym. Chem. 2017, 8, 4822-4829. link
Neary, W. J.; Kennemur, J. G. “Variable Temperature ROMP: Leveraging Low Ring Strain Thermodynamics to Achieve Well-Defined Polypentenamers” Macromolecules 2017, 50, 4935-4941. link