Synthesis of Macrocyclic Polymers Formed via Intramolecular Radical Trap-Assisted Atom Transfer Radical Coupling
| Autor: | Andrew F. Voter, Peter M. Findeis, Eric S. Tillman, Scott C. Radzinski |
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| Rok vydání: | 2022 |
| Předmět: |
Nitroxide mediated radical polymerization
Polymers and Plastics Organic Chemistry Radical polymerization Nitroso Photochemistry Radical cyclization Styrene Inorganic Chemistry Gel permeation chromatography chemistry.chemical_compound chemistry Cobalt-mediated radical polymerization Intramolecular force Polymer chemistry Materials Chemistry |
| Zdroj: | ACS macro letters. 1(8) |
| ISSN: | 2161-1653 |
| Popis: | The synthesis of cyclic polystyrene (PSt) with an alkoxyamine functionality has been accomplished by intramolecular radical coupling in the presence of a nitroso radical trap. Linear α,ω-dibrominated polystyrene, produced by the atom transfer radical polymerization (ATRP) of styrene using a dibrominated initiator, was subjected to chain-end activation via the atom transfer radical coupling (ATRC) process under pseudodilute conditions in the presence of 2-methyl-2-nitrosopropane (MNP). This radical trap-assisted, intramolecular ATRC (RTA-ATRC) produced cyclic polymers in greater than 90% yields, possessing ⟨G⟩ values in the 0.8–0.9 range as determined by gel permeation chromatography (GPC). Thermal-induced opening of the cycles, made possible by the incorporated alkoxyamine, resulted in a return to the original apparent molecular weight, further supporting the formation of cyclic polymers in the RTA-ATRC reaction. Liquid chromatography–mass spectrometry (LC-MS) provided direct confirmation of the cyclic ar... |
| Databáze: | OpenAIRE |
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