Abstract
Janus polymerization is featured as a combination of cationic and anionic growing ends in one living polymer chain. In the copolymerization of THF and CL catalyzed by lutetium triflates and initiated by propylene oxide, three stages are identified by kinetic study including (1) fast cationic polymerization with slow anionic one, (2) fast anionic polymerization with dormant cationic one, and (3) reactivation of cationic polymerization with coupling of anionic and cationic chain ends. In this work, density functional theory (DFT) calculation is employed to investigate the reaction details of ionic polymerization and dormancy. A “tripedal crow” configuration is proposed to illustrate the unique high-coordinated ligand exchange configuration in anionic polymerization in different stages. The trigger of dormancy is determined as chain structures rather than concentration of triflate anion according to both calculation and experimental results.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
You, L. X.; Ling, J. Janus polymerization. Macromolecules 2014, 47, 2219–2225.
Qiu, H.; Yang, Z.; Shah, M. I.; Mao, Z.; Ling, J. [PCL-b-P(THF-co-CL)]m multiblock copolymer synthesized by Janus polymerization. Polymer 2017, 128, 71*77.
Shah, M. I.; Yang, Z.; Li, Y.; Jiang, L.; Ling, J. Properties of electrospun nanofibers of multi-block copolymers of [poly-ε-caprolactone-b-poly(tetrahydrofuran-co-ε-caprolactone)]m synthesized by Janus polymerization. Polymers 2017, 9, 559.
Li, Y.; Bai, T.; Li, Y.; Ling, J. Branched polytetrahydrofuran and poly(tetrahydrofuran-co-ε-caprolactone) synthesized by Janus polymerization: A novel self-healing material. Macromol. Chem. Phys. 2017, 218, 1600450.
Li, Y.; von der Luhe, M.; Schacher, F. H.; Ling, J. 3-Miktoarm star terpolymers via Janus polymerization: One-step synthesis and self-assembly. Macromolecules 2018, 51, 4938–4944.
Li, Y.; Schacher, F. H.; Ling, J. Synthesis of polypeptoidpolycaprolactone- polytetrahydrofuran heterograft molecular polymer brushes via a combination of Janus polymerization and ROMP. Macromol. Rapid Commun. 2019, 1800905.
Qiu, H.; Yang, Z. N.; Ling, J. Facile synthesis of functional poly(ε-caprolactone) via Janus polymerization. Chinese J. Polym. Sci. 2019, 37.
Devlin, F.; Finley, J.; Stephens, P.; Frisch, M. Ab-initio calculation of vibrational absorption and circular-dichroism spectra using density-functional force-fields—A comparison of local, nonlocal, and hybrid density functionals. J. Phys. Chem. 1995, 99, 16883–16902.
Kim, K.; Jordan, K. Comparison of density-functional and MP2 calculations on the water monomer and dimer. J. Phys. Chem. 1994, 98, 10089–10094.
Fukui, K. The path of chemical reactions-the IRC approach. Acc. Chem. Res. 1981, 14, 363–368.
Bai, T. W.; Ling, J. NAM-TMS mechanism of α-amino acid N-carboxyanhydride polymerization: A DFT study. J. Phys. Chem. A 2017, 121, 4588–4593.
He, B. Z.; Su, H. F.; Bai, T. W.; Wu, Y. W.; Li, S. W.; Gao, M.; Hu, R. R.; Zhao, Z. J.; Qin, A. J.; Ling, J.; Tang, B. Z. Spontaneous amino-yne click polymerization: A powerful tool toward regio- and stereospecific poly(β-aminoacrylate)s. J. Am. Chem. Soc. 2017, 139, 5437–5443.
Frisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Scuseria, G. E.; Robb, M. A.; Cheeseman, J. R.; Scalmani, G.; Barone, V.; Petersson, G. A.; Nakatsuji, H.; Li, X.; Caricato, M.; Marenich, A. V.; Bloino, J.; Janesko, B. G.; Gomperts, R.; Mennucci, B.; Hratchian, H. P.; Ortiz, J. V.; Izmaylov, A. F.; Sonnenberg, J. L.; Williams; Ding, F.; Lipparini, F.; Egidi, F.; Goings, J.; Peng, B.; Petrone, A.; Henderson, T.; Ranasinghe, D.; Zakrzewski, V. G.; Gao, J.; Rega, N.; Zheng, G.; Liang, W.; Hada, M.; Ehara, M.; Toyota, K.; Fukuda, R.; Hasegawa, J.; Ishida, M.; Nakajima, T.; Honda, Y.; Kitao, O.; Nakai, H.; Vreven, T.; Throssell, K.; Montgomery Jr., J. A.; Peralta, J. E.; Ogliaro, F.; Bearpark, M. J.; Heyd, J. J.; Brothers, E. N.; Kudin, K. N.; Staroverov, V. N.; Keith, T. A.; Kobayashi, R.; Normand, J.; Raghavachari, K.; Rendell, A. P.; Burant, J. C.; Iyengar, S. S.; Tomasi, J.; Cossi, M.; Millam, J. M.; Klene, M.; Adamo, C.; Cammi, R.; Ochterski, J. W.; Martin, R. L.; Morokuma, K.; Farkas, O.; Foresman, J. B.; Fox, D. J. Gaussian 16 Rev. B.01, Gaussian, Inc,; Wallingford, CT, 2016.
Legault, C. Y. CYLview, 1.0b, Universite de Sherbrooke, 2009 (https://doi.org/www.cylview.org).
Ling, J.; Shen, J. G.; Hogen-Esch, T. E. A density functional theory study of the mechanisms of scandium-alkoxide initiated coordination-insertion ring-opening polymerization of cyclic esters. Polymer 2009, 50, 3575–3581.
Liu, J.; Ling, J.; Li, X.; Shen, Z. Monomer insertion mechanism of ring-opening polymerization of ε-caprolactone with yttrium alkoxide intermediate: A DFT study. J. Mol. Catal. AChem. 2009, 300, 59–64.
You, L. X.; Shen, Z. Q.; Kong, J.; Ling, J. A novel approach to RE-OR bond from in situ reaction of rare earth triflates and sodium alkoxides: A versatile catalyst for living ring-opening polymerization of ε-caprolactone. Polymer 2014, 55, 2404–2410.
Acknowledgements
This work was financially supported by the National Natural Science Foundation of China (No. 21871232) and the Zhejiang Provincial Natural Science Foundation of China (No. LR15B040001).
Author information
Authors and Affiliations
Corresponding author
Additional information
Invited article for special issue of “The 100th Anniversary of the Birth of Prof. Shi-Lin Yang”
Electronic supplementary material
Rights and permissions
About this article
Cite this article
Bai, TW., Ni, XF., Ling, J. et al. Mechanism of Janus Polymerization: A DFT Study. Chin J Polym Sci 37, 990–994 (2019). https://doi.org/10.1007/s10118-019-2318-9
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10118-019-2318-9