Volume 131, Issue 40 pp. 14449-14456
Forschungsartikel

Oxygen-Triggered Switchable Polymerization for the One-Pot Synthesis of CO2-Based Block Copolymers from Monomer Mixtures

Yajun Zhao

Yajun Zhao

School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, 430074 P. R. China

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Dr. Yong Wang

Corresponding Author

Dr. Yong Wang

School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, 430074 P. R. China

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Prof. Dr. Xingping Zhou

Prof. Dr. Xingping Zhou

School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, 430074 P. R. China

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Prof. Dr. Zhigang Xue

Prof. Dr. Zhigang Xue

School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, 430074 P. R. China

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Prof. Dr. Xianhong Wang

Prof. Dr. Xianhong Wang

Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, CAS, Changchun, 130022 P. R. China

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Xiaolin Xie

Xiaolin Xie

School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, 430074 P. R. China

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Prof. Dr. Rinaldo Poli

Prof. Dr. Rinaldo Poli

Laboratoire de Chimie de Coordination (LCC-CNRS), Université de Toulouse, UPS, INPT, 205, route de Narbonne, 31077 Toulouse, France

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First published: 08 July 2019
Citations: 9

Abstract

Switchable polymerization provides the opportunity to regulate polymer sequence and structure in a one-pot process from mixtures of monomers. Herein we report the use of O2 as an external stimulus to switch the polymerization mechanism from the radical polymerization of vinyl monomers mediated by (Salen)CoIII−R [Salen=N,N′-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine; R=alkyl] to the ring-opening copolymerization (ROCOP) of CO2/epoxides. Critical to this process is unprecedented monooxygen insertion into the Co−C bond, as rationalized by DFT calculations, leading to the formation of (Salen)CoIII−O−R as an active species to initiate ROCOP. Diblock poly(vinyl acetate)-b-polycarbonate could be obtained by ROCOP of CO2/epoxides with preactivation of (Salen)Co end-capped poly(vinyl acetate). Furthermore, a poly(vinyl acetate)-b-poly(methyl acrylate)-b-polycarbonate triblock copolymer was successfully synthesized by a (Salen)cobalt-mediated sequential polymerization with an O2-triggered switch in a one-pot process.

Conflict of interest

The authors declare no conflict of interest.

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