Quasi-alternating copolymerization of oxiranes driven by a benign acetate-based catalyst

Charlotte Fornaciari; Vincent Lemaur; Dario Pasini; Olivier Coulembier

doi:10.1038/s42004-023-01031-z

Quasi-alternating copolymerization of oxiranes driven by a benign acetate-based catalyst

Commun Chem. 2023 Oct 28;6(1):235. doi: 10.1038/s42004-023-01031-z.

Authors

Charlotte Fornaciari^{1

2}, Vincent Lemaur³, Dario Pasini⁴, Olivier Coulembier⁵

Affiliations

¹ Laboratory of Polymeric and Composite Materials (LPCM), Center of Innovation and Research in Materials and Polymers (CIRMAP), University of Mons, Place du Parc, 20, Mons, 7000, Belgium.
² Department of Chemistry, University of Pavia, Viale Taramelli, 10, Pavia, 27100, Italy.
³ Laboratory for Chemistry of Novel Materials, Materials Research Institute, University of Mons, Place du Parc, 20, 7000, Mons, Belgium.
⁴ Department of Chemistry, University of Pavia, Viale Taramelli, 10, Pavia, 27100, Italy. dario.pasini@unipv.it.
⁵ Laboratory of Polymeric and Composite Materials (LPCM), Center of Innovation and Research in Materials and Polymers (CIRMAP), University of Mons, Place du Parc, 20, Mons, 7000, Belgium. olivier.coulembier@umons.ac.be.

Abstract

Alternating copolymers are distinctly unique in comparison with other copolymers. Herein, an in-depth investigation of the oxyanionic ring-opening copolymerization of propylene oxide (PO) and allyl glycidyl ether (AGE) from benzyl alcohol (BnOH) activated with potassium acetate (KOAc) complexed by 18-crown-6 ether (18C6) is described. We demonstrate that the 18C6/KOAc complex is an efficient and benign catalytic system to promote copolymerization of both oxirane monomers, leading to well-defined polyethers with varied comonomer content and low dispersity values (Ɖ_M < 1.20). Kinetic analysis confirmed the controlled nature of the (co)polymerization process, and the determination of reactivity ratios revealed a quasi-alternating copolymerization profile, according to the Fineman-Ross method. The comparison between the quasi-alternating-type PO/AGE copolymerization and block or gradient copolymerization revealed significant differences, to confirm the different sequence incorporation in the different topological copolymers. These results highlight the great potential of 18C6/KOAc-mediated copolymerization process for the controlled sythesis of a series of copolymer topologies.