Logan M. Fenimore, Ph.D. (Fed)

Research Interests:

• Design and construction of (re)processable polymer networks containing thermoresponsive cross-links as sustainable alternatives to thermosets
• Synthesis-structure-property relationships of polymer networks and gels with complex architectures, i.e., percolated and/or non-percolated, dynamic or non-dynamic covalent cross-links, non-covalent associative bonding interactions, entanglements
• Temperature-, strain-, and strain-rate-dependent physics of associative-type dynamic covalent polybutadiene and polydimethylsiloxane networks
• Linear and non-linear viscoelastic characterization of polymer networks and gels by rheology and cavitation
• Structure-property-processing relationships of polyolefin elastomers and networks containing dissociative-type dynamic covalent cross-links

Selected Non-NIST Publications:

T. Wei, L. M. Fenimore, T. Lan, J. M. Torkelson. (2025). Connected nanoconfinement effects on glass transition temperature, fragility, and dye translational diffusivity in polystyrene thin films depend on molecular weight. The Journal of Chemical Physics, 163(15), 154902. DOI: 10.1063/5.0295491

L. M. Fenimore, M. J. Suazo, B. Chen, S. M. Barbon, H. A. Brown, E. Auyeung, C. Li Pi Shan, J. M. Torkelson. (2025). Recyclable ethylene-vinyl acetate covalent adaptable networks and their structure-property relationships. Macromolecules, 58(17), 9494-9503. DOI: 10.1021/acs.macromol.5c01213

L. M. Fenimore, M. J. Suazo, S. Mitchell, H. Mohammadi, K. M. McLoughlin, C. Gallaschun, P. Sewruk, M. Busch, J. M. Torkelson. (2025). Fully recyclable and remarkably robust cross-linked polyethylene networks via direct free-radical copolymerization with disulfide dynamic covalent bonds. Journal of the American Chemical Society, 147(31), 27179-27185. DOI: 10.1021/jacs.5c07720

M. J. Suazo, L. M. Fenimore, S. M. Barbon, H. Brown, E. Auyeung, G. Cespedes, C. Li Pi Shan, J. M. Torkelson. (2024). Extrudable and highly creep-resistant covalent adaptable networks made from polyethylene and ethylene/1-octene copolymers by reactive processing with aromatic disulfide cross-links. ACS Applied Polymer Materials, 6(23), 14772-14783. DOI: 10.1021/acsapm.4c02969

L. M. Fenimore, M. A. Bin Rusayyis, C. C. Onsager, M. A. Grayson, J. M. Torkelson. (2024). Reprocessable polymer networks containing sulfur-based, percolated dynamic covalent cross-links and percolated or non-percolated, static cross-links. Macromolecular Rapid Communications, 45(18), 2400303. DOI: 10.1002/marc.202400303

S. Serna, N. S. Purwanto, L. M. Fenimore, J. M. Torkelson. (2024). Increasing the cross-link density in a dual dissociative and associative polythiourethane covalent adaptable network improves both creep resistance and extrudability. Polymer, 306, 127232. DOI: 10.1016/j.polymer.2024.127232

L. M. Fenimore, M. J. Suazo, J. M. Torkelson. (2024). Covalent adaptable networks made by reactive processing of highly entangled polymer: Synthesis-structure-thermomechanical property-reprocessing relationship in covalent adaptable networks. Macromolecules, 57(6), 2756-2772. DOI: 10.1021/acs.macromol.3c02515

L. M. Fenimore, B. Chen, Y. Chen, S. M. Barbon, H. A. Brown, E. Auyeung, C. Li Pi Shan, J. M. Torkelson. (2024). Covalent adaptable networks and thermosets of multi-block ethylene/1-octene copolymers made by free-radical processing: Effects of melt flow index and crystallinity on thermomechanical properties and reprocessability. European Polymer Journal, 202, 112661. DOI: 10.1016/j.eurpolymj.2023.112661

B. Chen, L. M. Fenimore, Y. Chen, S. M. Barbon, H. A. Brown, E. Auyeung, C. Li Pi Shan, J. M. Torkelson. (2023). Novel covalent adaptable networks (CANs) of ethylene/1-octene copolymers (EOCs) made by free-radical processing: comparison of structure–property relationships of EOC CANs with EOC thermosets. Polymer Chemistry, 14(31), 3621-3637. DOI: 10.1039/D3PY00444A

L. M. Fenimore, B. Chen, J. M. Torkelson. (2022). Simple upcycling of virgin and waste polyethylene into covalent adaptable networks: catalyst-free, radical-based reactive processing with dialkylamino disulfide bonds. Journal of Materials Chemistry A, 10(46), 24726-24745.  DOI: 10.1039/D2TA06364

NIST, Macromolecular Architectures

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Plastics at the Edge of the World

Finalist, Eastman Chemical Student Award in Applied Polymer Science - ACS Fall National Meeting & Exposition (PMSE), 2025

Finalist, Frank J. Padden Jr. Award - APS Global Physics Summit (DPOLY), 2025

NIST NRC Postdoctoral Research Associateship - National Academies of Sciences, Engineering, and Medicine, 2024

1st Prize, Excellence in Graduate Student Research Symposium - AIChE Annual Meeting (8A Polymers), 2024

Distinguished Graduate Researcher Award - Department of Chemical and Biological Engineering, Northwestern University, 2024

Graduate Teaching Fellowship - Searle Center for Advancing Learning and Teaching, Northwestern University, 2024

Ryan Fellowship - International Institute of Nanotechnology, Northwestern University, 2023

Graduate Research Fellowship - National Science Foundation, 2021

Omega Chi Epsilon Honor Society - Rose-Hulman Institute of Technology, 2018