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Two‐Stage Pseudoliving Radical Polymerization under the Influence of Triphenylmethyl Radicals
Author(s) -
Chernikova Elena V.,
Pokataeva Zoya A.,
Garina Elizaveta S.,
Lachinov Mikhail B.,
Golubev Vladimir B.
Publication year - 2001
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/1521-3935(20010101)202:1<188::aid-macp188>3.0.co;2-v
Subject(s) - polymerization , radical , chemistry , polymer chemistry , radical polymerization , cobalt mediated radical polymerization , monomer , bulk polymerization , photochemistry , chain transfer , chain termination , methyl methacrylate , kinetic chain length , ionic polymerization , polymer , living free radical polymerization , nitroxide mediated radical polymerization , organic chemistry
The kinetics and the mechanism of radical thermal polymerization of methyl methacrylate and styrene in bulk at 80°C initiated by hexaphenylethane (a source of triphenylmethyl radicals) were studied. It was found that polymerization of both monomers proceeded according to a two‐stage pseudoliving mechanism. The first stage features the formation and accumulation of reactive oligomeric product due to a fast consumption of triphenylmethyl radicals in the reactions of initiation and termination of the growing chains. The oligomeric product reinitiates polymerization at the second stage. Polymerization in both systems is characterized by a successive increase in the molecular weights of the polymers up to high conversions. It was shown that at low concentration of triphenylmethyl radicals the pseudoliving mechanism of the polymerization is violated appreciably; the reasons for this phenomenon are discussed.