This study explores the relationship between monomer stereochemistry and the materials properties of thermosets generated by frontal ring-opening metathesis polymerization (FROMP). The exo- and endo-stereoisomers of dicyclopentadiene (DCPD) undergo rapid FROMP to fabricate robust thermosets within seconds. The exo-isomer provides significant benefits compared to the commonplace endo-DCPD resins; exo-DCPD supports faster fronts (≈3 times faster) than the endo-analogue and is an easier-to-handle liquid at room temperature. This work is among the first to explore the materials properties of p(exo-DCPD) thermosets. Here, we demonstrate a significant decrease in Tg for products derived from exo-DCPD, despite having a similar rubbery plateau compared to p(endo-DCPD). Soluble oligomers were synthesized as models to probe the microstructural features affected by the monomer stereochemistry. Interestingly, hydrogenated oligomers of endo-DCPD exhibit slight differences in stereoregularity compared to their exo-counterparts. Finally, we incorporated a bisnorbornenyl cross-linker in exo-DCPD resins to boost the polymer Tg, while also maintaining fronts that propagate faster than endo-DCPD.
Wang, Hanlin M., et al. "Frontal Polymerization of Stereoisomers: Distinct Microstructures and Properties in <em>Endo-</em> and <em>Exo-</em>Dicyclopentadiene Thermosets." Macromolecules, vol. 57, no. 1, Dec. 2023. https://doi.org/10.1021/acs.macromol.3c02177
Wang, Hanlin M., Suslick, Benjamin A., Lessard, Jacob J., Yu, Christina H., Saengow, Chaimongkol, Ewoldt, Randy H., & Moore, Jeffrey S. (2023). Frontal Polymerization of Stereoisomers: Distinct Microstructures and Properties in <em>Endo-</em> and <em>Exo-</em>Dicyclopentadiene Thermosets. Macromolecules, 57(1). https://doi.org/10.1021/acs.macromol.3c02177
Wang, Hanlin M., Suslick, Benjamin A., Lessard, Jacob J., et al., "Frontal Polymerization of Stereoisomers: Distinct Microstructures and Properties in <em>Endo-</em> and <em>Exo-</em>Dicyclopentadiene Thermosets," Macromolecules 57, no. 1 (2023), https://doi.org/10.1021/acs.macromol.3c02177
@article{osti_2339599,
author = {Wang, Hanlin M. and Suslick, Benjamin A. and Lessard, Jacob J. and Yu, Christina H. and Saengow, Chaimongkol and Ewoldt, Randy H. and Moore, Jeffrey S.},
title = {Frontal Polymerization of Stereoisomers: Distinct Microstructures and Properties in <em>Endo-</em> and <em>Exo-</em>Dicyclopentadiene Thermosets},
annote = {This study explores the relationship between monomer stereochemistry and the materials properties of thermosets generated by frontal ring-opening metathesis polymerization (FROMP). The exo- and endo-stereoisomers of dicyclopentadiene (DCPD) undergo rapid FROMP to fabricate robust thermosets within seconds. The exo-isomer provides significant benefits compared to the commonplace endo-DCPD resins; exo-DCPD supports faster fronts (≈3 times faster) than the endo-analogue and is an easier-to-handle liquid at room temperature. This work is among the first to explore the materials properties of p(exo-DCPD) thermosets. Here, we demonstrate a significant decrease in Tg for products derived from exo-DCPD, despite having a similar rubbery plateau compared to p(endo-DCPD). Soluble oligomers were synthesized as models to probe the microstructural features affected by the monomer stereochemistry. Interestingly, hydrogenated oligomers of endo-DCPD exhibit slight differences in stereoregularity compared to their exo-counterparts. Finally, we incorporated a bisnorbornenyl cross-linker in exo-DCPD resins to boost the polymer Tg, while also maintaining fronts that propagate faster than endo-DCPD.},
doi = {10.1021/acs.macromol.3c02177},
url = {https://www.osti.gov/biblio/2339599},
journal = {Macromolecules},
issn = {ISSN 0024-9297},
number = {1},
volume = {57},
place = {United States},
publisher = {American Chemical Society},
year = {2023},
month = {12}}