POS1-0256
Development of Controlled Radical Polymerization with Thioether Initiators and Nickel Complexes
When and Where
Nov 30, -0001
12:00am - 12:00am
Presenter(s)
Mina Yoneguchi (Nagoya University)
Co-Author(s)
Abstract
Controlled radical polymerization (CRP) has attracted significant attention in precision polymer synthesis. To date, various CRPs have been reported utilizing a variety of dormant species, such as carbon–halogen bonds. Developing novel CRPs based on different dormant species is expected to expand the scope of polymer design. In this study, we focused on thioethers as novel initiators because of their structural diversity and ease of synthesis. In addition, the reductive cleavage of C-S bonds using Ni(COD)2 has been reported in transformation of organic molecules. Therefore, this study aimed to develop a novel CRP based on the C-S bond cleavage of thioethers mediated by nickel complexes. We investigated the effects of the structures of thioether initiators and nickel ligands on the radical polymerization of vinyl monomers.
Initially, we examined the polymerization of methyl methacrylate with Ni(COD)2 and phosphine ligands in toluene at 80 °C. The polymerization proceeded in the presence of the thioether initiator, and the incorporation of the initiator moiety into the resulting polymer was confirmed. However, β-hydrogen elimination occurred via a chain-transfer reaction.
To address this issue, we subsequently investigated the polymerization of styrene and methyl acrylate. The polymerization behavior, such as polymerization rate and the molecular weight of the resulting polymers, significantly depended on the structures of the nickel ligands and thioether initiators. Under optimized conditions for each monomer, the side reactions were effectively suppressed, and the molecular weight of the resulting polymers progressively increased with the progress of the polymerization.
These results indicate that CRP using thioethers and nickel complexes efficiently proceeds under the optimized conditions, yielding polymers with predictable molecular weights close to the calculated values.
Initially, we examined the polymerization of methyl methacrylate with Ni(COD)2 and phosphine ligands in toluene at 80 °C. The polymerization proceeded in the presence of the thioether initiator, and the incorporation of the initiator moiety into the resulting polymer was confirmed. However, β-hydrogen elimination occurred via a chain-transfer reaction.
To address this issue, we subsequently investigated the polymerization of styrene and methyl acrylate. The polymerization behavior, such as polymerization rate and the molecular weight of the resulting polymers, significantly depended on the structures of the nickel ligands and thioether initiators. Under optimized conditions for each monomer, the side reactions were effectively suppressed, and the molecular weight of the resulting polymers progressively increased with the progress of the polymerization.
These results indicate that CRP using thioethers and nickel complexes efficiently proceeds under the optimized conditions, yielding polymers with predictable molecular weights close to the calculated values.
