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Cobalt‐Mediated Radical Polymerization of Acrylonitrile: Kinetics Investigations and DFT Calculations
Author(s) -
Debuigne Antoine,
Michaux Catherine,
Jérôme Christine,
Jérôme Robert,
Poli Rinaldo,
Detrembleur Christophe
Publication year - 2008
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200800371
Subject(s) - acrylonitrile , polymerization , chemistry , polymer chemistry , molar mass , solvent , cobalt , chain transfer , adduct , molar mass distribution , radical polymerization , cobalt mediated radical polymerization , dimethyl sulfoxide , photochemistry , polymer , copolymer , organic chemistry
The successful controlled homopolymerization of acrylonitrile (AN) by cobalt‐mediated radical polymerization (CMRP) is reported for the first time. As a rule, initiation of the polymerization was carried out starting from a conventional azo‐initiator (V‐70) in the presence of bis(acetylacetonato)cobalt(II) ([Co(acac) 2 ]) but also by using organocobalt(III) adducts. Molar concentration ratios of the reactants, the temperature, and the solvent were tuned, and the effect of these parameters on the course of the polymerization is discussed in detail. The best level of control was observed when the AN polymerization was initiated by an organocobalt(III) adduct at 0 °C in dimethyl sulfoxide. Under these conditions, poly(acrylonitrile) with a predictable molar mass and molar mass distribution as low as 1.1 was prepared. A combination of kinetic data, X‐ray analyses, and DFT calculations were used to rationalize the results and to draw conclusions on the key role played by the solvent molecules in the process. These important mechanistic insights also permit an explanation of the unexpected “solvent effect” that allows the preparation of well‐defined poly(vinyl acetate)‐ b ‐poly(acrylonitrile) by CMRP.