Hydroperoxide Traces in Common Cyclic Ethers as Initiators for Controlled RAFT Polymerizations

• Published in: Macromolecular rapid communications. 2018-04, Vol.39 (7), p.e1700683-n/a
• Main Authors: Eggers, Steffen, Abetz, Volker
• Format: Article
• Language: English
• Subjects: Addition polymerization; alternative strategies to activate chain transfer agents; block copolymers; Chain transfer; Chemical synthesis; ether hydroperoxides; Ethers; Initiators; Kinetics; Laboratory equipment; MALDI‐ToF‐MS; Monomers; Polymerization; Polymers; Reaction kinetics; reversible addition–fragmentation chain transfer (RAFT); Tetrahydrofuran
• ISSN: 1022-1336; 1521-3927
• DOI: 10.1002/marc.201700683

Herein, a reversible addition–fragmentation chain transfer (RAFT) polymerization is introduced for reactive monomers like N‐acryloylpyrrolidine or N,N‐dimethylacrylamide working without a conventional radical initiator. As a very straightforward proof of principle, the method takes advantage of the usually inconvenient radical‐generating hydroperoxide contaminations in cyclic ethers like tetrahydrofuran or 1,4‐dioxane, which are very common solvents in polymer sciences. The polymerizations are surprisingly well controlled and the polymers can be extended with a second block, indicating their high livingness. “Solvent‐initiated” RAFT polymerizations hence prove to be a feasible access to tailored materials with minimal experimental effort and standard laboratory equipment, only requiring the following ingredients: hydroperoxide‐contaminated solvent, monomer, and RAFT agent. In other respects, however, the potential coinitiating ability of the used solvent is to be considered when investigating the kinetics of RAFT polymerizations or aiming for the synthesis of high‐livingness polymers, e.g., multiblock copolymers. It turns out that common analytical grade ethers can initiate well‐controlled reversible addition–fragmentation chain transfer (RAFT) polymerizations of quickly propagating acrylamides. The initiation proceeds via activation of the RAFT agent with ether radicals, which are generated from hydroperoxides being commonly present in those solvents. Being highly straightforward, the method needs no advanced laboratory equipment or experimental experience.