Next Article in Journal
Studying the Ring-Opening Polymerization of 1,5-Dioxepan-2-one with Organocatalysts
Previous Article in Journal
Thiol–Ene Photopolymerization: Scaling Law and Analytical Formulas for Conversion Based on Kinetic Rate and Thiol–Ene Molar Ratio
Open AccessArticle

DFT Visualization and Experimental Evidence of BHT-Mg-Catalyzed Copolymerization of Lactides, Lactones and Ethylene Phosphates

1
Chemistry Department, M.V. Lomonosov Moscow State University, 1–3 Leninskie Gory, 119991 Moscow, Russia
2
A.V. Topchiev Institute of Petrochemical Synthesis RAS, 29 Leninsky Pr., 119991 Moscow, Russia
3
Joint-stock company “Institute of petroleum refining and petrochemistry”, 12 Iniciativnaya Str., 450065 Ufa, Republic of Bashkortostan, Russia
*
Author to whom correspondence should be addressed.
Polymers 2019, 11(10), 1641; https://doi.org/10.3390/polym11101641
Received: 13 September 2019 / Revised: 5 October 2019 / Accepted: 8 October 2019 / Published: 10 October 2019
Catalytic ring-opening polymerization (ROP) of cyclic esters (lactides, lactones) and cyclic ethylene phosphates is an effective way to process materials with regulated hydrophilicity and controlled biodegradability. Random copolymers of cyclic monomers of different chemical nature are highly attractive due to their high variability of characteristics. Aryloxy-alkoxy complexes of non-toxic metals such as derivatives of 2,6-di-tert-butyl-4-methylphenoxy magnesium (BHT-Mg) complexes are effective coordination catalysts for homopolymerization of all types of traditional ROP monomers. In the present paper, we report the results of density functional theory (DFT) modeling of BHT-Mg-catalyzed copolymerization for lactone/lactide, lactone/ethylene phosphate and lactide/ethylene phosphate mixtures. ε-Caprolactone (ε-CL), l-lactide (l-LA) and methyl ethylene phosphate (MeOEP) were used as examples of monomers in DFT simulations by the Gaussian-09 program package with the B3PW91/DGTZVP basis set. Both binuclear and mononuclear reaction mechanistic concepts have been applied for the calculations of the reaction profiles. The results of calculations predict the possibility of the formation of random copolymers based on l-LA/MeOEP, and substantial hindrance of copolymerization for ε-CL/l-LA and ε-CL/MeOEP pairs. From the mechanistic point of view, the formation of highly stable five-membered chelate by the products of l-LA ring-opening and high donor properties of phosphates are the key factors that rule the reactions. The results of DFT modeling have been confirmed by copolymerization experiments. View Full-Text
Keywords: ring-opening polymerization; random copolymers; ethylene phosphate; lactide; caprolactone; DFT; magnesium phenoxide ring-opening polymerization; random copolymers; ethylene phosphate; lactide; caprolactone; DFT; magnesium phenoxide
Show Figures

Graphical abstract

MDPI and ACS Style

Nifant’ev, I.; Shlyakhtin, A.; Kosarev, M.; Gavrilov, D.; Karchevsky, S.; Ivchenko, P. DFT Visualization and Experimental Evidence of BHT-Mg-Catalyzed Copolymerization of Lactides, Lactones and Ethylene Phosphates. Polymers 2019, 11, 1641.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop