References of "Piette, Yasmine"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailSynthesis of poly(vinyl acetate)-b-poly(vinyl chloride) block copolymers by cobalt-mediated radical polymerization (CMRP)
Piette, Yasmine; Debuigne, Antoine ULiege; Bodart, Vinent et al

in Polymer Chemistry (2013), 4(5), 1685-1693

The synthesis of poly(vinyl acetate)-b-poly(vinyl chloride) (PVAc-b-PVC) block copolymers by Cobalt-Mediated Radical Polymerization (CMRP) is investigated for the first time in this paper. A PVAc–Co(acac ... [more ▼]

The synthesis of poly(vinyl acetate)-b-poly(vinyl chloride) (PVAc-b-PVC) block copolymers by Cobalt-Mediated Radical Polymerization (CMRP) is investigated for the first time in this paper. A PVAc–Co(acac)2 macroinitiator is prepared by CMRP using the V-70/Co(acac)2 binary system or a preformed alkylcobalt(III) compound. Then, the block copolymerization occurs in the bulk at 40 °C by the addition of VC. The addition of water to the polymerization medium or the slow generation of alkyl radicals during the whole polymerization is beneficial to the process by consuming part of the excess of deactivator (Co(acac)2) that blocks the polymer chains into the dormant form. Dynamic light scattering (DLS) measurements and AFM analyses evidence that the PVAc-b-PVC forms core–shell micelles in a selective solvent of the PVAc block, i.e. methanol, evidencing the blocky structure of the copolymer. PVAc-b-P(VC-co-VAc) copolymers are also successfully prepared by initiating the radical copolymerization of VC and VAc at 40 °C from a PVAc–Co(acac)2 macroinitiator. [less ▲]

Detailed reference viewed: 74 (9 ULiège)
Full Text
Peer Reviewed
See detailCobalt-mediated radical (co)polymerization of vinyl chloride and vinyl acetate
Piette, Yasmine; Debuigne, Antoine ULiege; Jérôme, Christine ULiege et al

in Polymer Chemistry (2012), 3(10), 2880-2891

The cobalt mediated radical polymerization (CMRP) of vinyl chloride (VC) in the presence of bis(acetylacetonato)cobalt(II) (Co(acac)2) as a controlling agent is presented for the first time. Using an ... [more ▼]

The cobalt mediated radical polymerization (CMRP) of vinyl chloride (VC) in the presence of bis(acetylacetonato)cobalt(II) (Co(acac)2) as a controlling agent is presented for the first time. Using an alkyl-Co(III) compound (R0–(CH2–CHOAc)<4–Co(acac)2; R0 = (H3C)2(OCH3)C–CH2–C(CH3)(CN)–) as an initiator, the bulk polymerization under non-isotherm conditions is controlled. 1H NMR spectra of the resulting PVC show that the CMRP process does not significantly affect the level of defects compared to a PVC prepared by a conventional free radical polymerization at the same temperature. Using the same alkyl-cobalt(III) compound, the copolymerization of VC and VAc is controlled at 40 °C provided that enough VAc (about 40 mol%) is present in the polymerization medium to moderate the VC polymerization. In line with reactivity ratios, VC is preferentially incorporated in the polymer at the early stages of the polymerization, leading to copolymers with a high VC content at moderate conversions. This is the first report of a CMRP of VC and of the synthesis of well-defined statistical PVC-co-PVAc copolymers by this technique. [less ▲]

Detailed reference viewed: 58 (19 ULiège)
Full Text
Peer Reviewed
See detailSynthetic and mechanistic inputs of photochemistry into the bisacetylacetonatocobalt- mediated radical polymerization of n-butyl acrylate and vinyl acetate
Detrembleur, Christophe ULiege; Versace, Davy-Louis; Piette, Yasmine et al

in Polymer Chemistry (2012), 3(7), 1856-1866

The input of photochemistry to the Co(acac)2 mediated radical polymerization (CMRP) of n-butyl acrylate and vinyl acetate is investigated for the first time. Upon UV irradiation, photoinitiators are able ... [more ▼]

The input of photochemistry to the Co(acac)2 mediated radical polymerization (CMRP) of n-butyl acrylate and vinyl acetate is investigated for the first time. Upon UV irradiation, photoinitiators are able to initiate the n-butyl acrylate polymerization that remains controlled up to very high molar masses (>4 × 106 g mol−1) with low polydispersities. The photoinitiator as well as the irradiation time must be appropriately chosen to reach acceptable initiator efficiencies while maintaining an optimal control over the polymerization. Laser flash photolysis experiments were then carried out to evidence the addition of alkyl and phosphonyl radicals onto Co(acac)2 and to determine the rate constants (kdeact) of these addition reactions that were still lacking. Finally, both kinetics of polymerization and spin-trapping experiments have evidenced that the C–Co bond at the extremity of the dormant polymer chains can be easily photocleaved. UV irradiation can therefore be considered as an additional lever for tuning the reactivity of the CMRP process mediated by Co(acac)2. [less ▲]

Detailed reference viewed: 68 (12 ULiège)
Full Text
See detailControlled radical polymerization of halogenated monomers
Bodart, Vincent; Piette, Yasmine; Detrembleur, Christophe ULiege et al

Patent (2012)

Process for the preparation of a halogenated polymer comprising a controlled radical polymerization step of at least one monomer containing at least one halogen-carbon bond performed in the presence of an ... [more ▼]

Process for the preparation of a halogenated polymer comprising a controlled radical polymerization step of at least one monomer containing at least one halogen-carbon bond performed in the presence of an organo-cobalt complex, said polymerization step being further carried out in the presence of at least one ligand. [less ▲]

Detailed reference viewed: 31 (8 ULiège)
Full Text
See detailControlled radical polymerization of halogenated monomers
Bodart, Vincent; Piette, Yasmine; Detrembleur, Christophe ULiege et al

Patent (2012)

Process for the preparation of a halogenated polymer comprising a controlled radical polymerization step of at least one monomer containing at least one halogen-carbon bond, performed in the presence of ... [more ▼]

Process for the preparation of a halogenated polymer comprising a controlled radical polymerization step of at least one monomer containing at least one halogen-carbon bond, performed in the presence of an organo-cobalt complex, said polymerization step being further carried out in non-isotherm conditions. [less ▲]

Detailed reference viewed: 34 (12 ULiège)
Full Text
Peer Reviewed
See detailKey role of intramolecular metal chelation and hydrogen bonding in the cobalt-mediated radical polymerization of N-vinyl amides
Debuigne, Antoine ULiege; Morin, Aurélie; Kermagoret, Anthony ULiege et al

in Chemistry (2012), 18

This work reveals the preponderance of an intramolecular metal chelation phenomenon in a controlled radical polymerization system involving the reversible trapping of the radical chains by a cobalt ... [more ▼]

This work reveals the preponderance of an intramolecular metal chelation phenomenon in a controlled radical polymerization system involving the reversible trapping of the radical chains by a cobalt complex, i.e. the bis(acetylacetonato)cobalt(II). The cobalt-mediated radical polymerization (CMRP) of a series of N-vinyl amides was considered in order to evidence the effect of the cobalt chelation by the amide moiety of the last monomer unit of the chain. The latter reinforces the cobalt-polymer bond in the order N-vinylpyrrolidone < N-vinyl caprolactam < N-methyl-N-vinyl acetamide, and is responsible for the optimal control of the polymerizations observed for the last two monomers. Such a double linkage between the controlling agent and the polymer, via a covalent bond and a dative one, is unique in the field of controlled radical polymerization and represents a powerful opportunity to fine tune the equilibrium between latent and free radicals. The possible hydrogen bond formation is also taken into account in the case of N-vinyl acetamide and N-vinyl formamide. These results are essential for understanding factors influencing a Co-C bond strength in general, and the CMRP mechanism in particular, but also for developing a powerful platform for the synthesis of new precision poly(N-vinyl amide)s, an important class of polymers which sustains numerous applications today. [less ▲]

Detailed reference viewed: 141 (18 ULiège)