title: Cobalt-Mediated Radical Polymerization of Vinyl Acetate and Acrylonitrile in Supercritical Carbon Dioxide.
abstract: Cobalt-mediated radical polymerization (CMRP) of vinyl acetate (VAc) is successfully achieved in supercritical carbon dioxide (scCO2). CMRP of VAc is conducted using an alkyl-cobalt(III) adduct that is soluble in scCO2. Kinetics studies coupled to visual observations of the polymerization medium highlight that the melt viscosity and PVAc molar mass (Mn) are key parameters that affect the CMRP in scCO2. It is noticed that CMRP is controlled for Mn up to 10 000 g mol(-1), but loss of control is progressively observed for higher molar masses when PVAc precipitates in the polymerization medium. Low molar mass PVAc macroinitiator, prepared by CMRP in scCO2, is then successfully used to initiate the acrylonitrile polymerization. PVAc-b-PAN block copolymer is collected as a free flowing powder at the end of the process although the dispersity of the copolymer increases with the reaction time. Although optimization is required to decrease the dispersity of the polymer formed, this CMRP process opens new perspectives for macromolecular engineering in scCO2 without the utilization of fluorinated comonomers or organic solvents.
authors.affiliation: Chemistry Department, Center for Education and Research on Macromolecules (CERM), University of Liege (ULg), Sart-Tilman B6a, 4000, Liege, Belgium.
authors.forename: Anthony
authors.initials: A
authors.lastname: Kermagoret
authors.affiliation: Chemistry Department, Center for Education and Research on Macromolecules (CERM), University of Liege (ULg), Sart-Tilman B6a, 4000, Liege, Belgium.
authors.forename: Ngoc Do Quyen
authors.initials: Ndo Q
authors.lastname: Chau
authors.affiliation: Chemistry Department, Center for Education and Research on Macromolecules (CERM), University of Liege (ULg), Sart-Tilman B6a, 4000, Liege, Belgium.
authors.forename: Bruno
authors.initials: B
authors.lastname: Grignard
authors.affiliation: Chemistry Department, Center for Education and Research on Macromolecules (CERM), University of Liege (ULg), Sart-Tilman B6a, 4000, Liege, Belgium.
authors.forename: Daniela
authors.initials: D
authors.lastname: Cordella
authors.affiliation: Chemistry Department, Center for Education and Research on Macromolecules (CERM), University of Liege (ULg), Sart-Tilman B6a, 4000, Liege, Belgium.
authors.forename: Antoine
authors.initials: A
authors.lastname: Debuigne
authors.affiliation: Chemistry Department, Center for Education and Research on Macromolecules (CERM), University of Liege (ULg), Sart-Tilman B6a, 4000, Liege, Belgium.
authors.forename: Christine
authors.initials: C
authors.lastname: Jérôme
authors.affiliation: Chemistry Department, Center for Education and Research on Macromolecules (CERM), University of Liege (ULg), Sart-Tilman B6a, 4000, Liege, Belgium.
authors.forename: Christophe
authors.initials: C
authors.lastname: Detrembleur
mesh_terms: D000181:Acrylonitrile / Q000737:chemistry*; D002245:Carbon Dioxide / Q000737:chemistry*; D002384:Catalysis; D003035:Cobalt / Q000737:chemistry*; D007700:Kinetics; D008970:Molecular Weight; D058105:Polymerization; D014753:Vinyl Compounds / Q000737:chemistry*
chemical_list: D014753:Vinyl Compounds; D002245:Carbon Dioxide; D003035:Cobalt; C011566:vinyl acetate; D000181:Acrylonitrile
keywords: cobalt-mediated radical polymerization; controlled radical polymerization; poly(acrylonitrile); poly(vinyl acetate); supercritical carbon dioxide