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See detailCobalt-mediated radical copolymerization of conjugated and non-conjugated monomers
Hurtgen, Marie ULg; Debuigne, Antoine ULg; Fustin, Charles-André et al

in Polymer Preprints (2011), 52(2), 626-627

Detailed reference viewed: 27 (9 ULg)
See detailCobalt-mediated radical polymerization
Debuigne, Antoine ULg; Jérôme, Robert ULg; Jérôme, Christine ULg et al

in Schlüter, Dieter A.; Hawker, Craig; Sakamoto, Junji (Eds.) Synthesis of polymers: new structures and methods (2012)

Detailed reference viewed: 37 (10 ULg)
See detailCobalt-mediated radical polymerization (CMRP) and coupling reaction (CMRC): mechanistic advances ans synthetic opportunities
Debuigne, Antoine ULg; Poli, Rinaldo; De Winter, Julien et al

Poster (2009, December 14)

Detailed reference viewed: 39 (11 ULg)
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See detailCobalt-mediated radical polymerization (CMRP) of vinyl acetate initiated by redox systems: Toward the scale-up of CMRP
Bryaskova, Rayna ULg; Detrembleur, Christophe ULg; Debuigne, Antoine ULg et al

in Macromolecules (2006), 39(24), 8263-8268

A redox initiating system was developed in order to bypass 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile) (V70) as the initiator of the cobalt-mediated radical polymerization (CMRP) of vinyl acetate ... [more ▼]

A redox initiating system was developed in order to bypass 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile) (V70) as the initiator of the cobalt-mediated radical polymerization (CMRP) of vinyl acetate (VAc) in the presence of cobalt(II) acetylacetonate (Co(acac)(2)). It is indeed a problem to stock up with V70 because of needed storage at -20 degrees C during transportation. This paper reports on the controlled CMRP of VAc initiated by ascorbic acid combined with either lauroyl peroxide or benzoyl peroxide at 30 degrees C. Substitution of citric acid for ascorbic acid results in faster polymerization whereas the polymerization control is maintained. All these improvements facilitate the implementation of the vinyl acetate CMRP and open the door to the scale-up of the process. [less ▲]

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See detailCobalt-mediated radical polymerization for the precision design of novel poly(ionic liquid) copolymers in aqueous media
Cordella, Daniela ULg; Kermagoret, Anthony; Debuigne, Antoine ULg et al

Poster (2015, September 11)

Poly(ionic liquid)s (PILs) have emerged as a special class of polyelectrolyte materials, featuring tunable solubility, high ionic conductivity, and a broad range of glass transition temperatures. Due to ... [more ▼]

Poly(ionic liquid)s (PILs) have emerged as a special class of polyelectrolyte materials, featuring tunable solubility, high ionic conductivity, and a broad range of glass transition temperatures. Due to their specific properties emanating from the ionic liquid (IL) units and their intrinsic polymeric nature, PILs find potential applications in various areas, such as analytical chemistry, biotechnology, gas separation, dispersants, solid ionic conductors for energy, catalysis, etc. In recent years, controlled radical polymerization (CRP) techniques have been applied to the synthesis of structurally well-defined PILs, with control attained over molar mass, dispersity, and end-group fidelity. In this poster, we will report on the implementation of cobalt-mediated radical polymerization (CMRP) technique for the precision synthesis of unprecedented PILs (co)polymers. We will discuss how an organocobalt complex can efficiently control the growth of vinyl imidazolium chains and lead to PILs with predicted molar masses and low polydispersities under mild experimental conditions, thus at low temperature and using water as a green polymerization medium. The huge potential of this system will be highlighted by describing the one-pot synthesis of all vinyl imidazolium-based block copolymers in aqueous media. This CMRP is unique for providing well-defined vinyl imidazolium based-copolymers for advanced PILs applications. [less ▲]

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See detailCobalt-mediated radical polymerization of acrylonitrile: Kinetics investigations and DFT calculations
Debuigne, Antoine ULg; Michaux, Catherine; Jérôme, Christine ULg et al

in Chemistry : A European Journal (2008), 14(25), 7623-7637

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 ... [more ▼]

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. [less ▲]

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See detailCobalt-mediated radical polymerization of vinyl acetate and acrylonitrile in supercritical carbon dioxide
Kermagoret; Chau, Ngoc Do Quyen; Grignard, Bruno ULg et al

in Macromolecular Rapid Communications (2016), 39(6), 539-544

Cobalt-mediated radical polymerization (CMRP) of vinyl acetate (VAc) is successfully achieved in supercritical carbon dioxide (scCO 2 ). CMRP of VAc is conducted using an alkyl-cobalt(III) adduct that is ... [more ▼]

Cobalt-mediated radical polymerization (CMRP) of vinyl acetate (VAc) is successfully achieved in supercritical carbon dioxide (scCO 2 ). 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 M n 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. [less ▲]

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See detailCobalt-mediated radical polymerization of vinyl acetate in miniemulsion: Very fast formation of stable poly(vinyl acetate) latexes at low temperature
Detrembleur, Christophe ULg; Debuigne, Antoine ULg; Bryaskova, Rayna ULg et al

in Macromolecular Rapid Communications (2006), 27(1), 37-41

Poly(vinyl acetate) macroinitiators end-capped by a Co(acac)(2) complex (PVAc-Co(acac)(2)), prepared in bulk by cobalt-mediated radical polymerization (CMRP), are used for the controlled radical ... [more ▼]

Poly(vinyl acetate) macroinitiators end-capped by a Co(acac)(2) complex (PVAc-Co(acac)(2)), prepared in bulk by cobalt-mediated radical polymerization (CMRP), are used for the controlled radical polymerization of vinyl acetate in miniemulsion to give high-molecular-weight polymers and high monomer conversion. Stable poly(vinyl acetate) latexes with solid contents ranging from 25 to 30 wt.-% are prepared within unusually short reaction times (similar to 1 h) at low temperatures (0-30 degrees C). [less ▲]

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See detailCobalt-mediated radical polymerization of vinyl acetate: a new tool for macromolecular engineering
Debuigne, Antoine ULg; Detrembleur, Christophe ULg; Bryaskova, Rayna et al

in Matyjaszewski, Krzysztof (Ed.) Controlled/living radical polymerization: from synthesis to materials (2006)

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See detailCobalt-mediated radical polymerization of vinyl monomers: investigation of cobalt-coordination
Debuigne, Antoine ULg; Piette, Yasmine ULg; Poli, Rinaldo et al

Poster (2009, September 17)

Controlled Radical Polymerization techniques have been developed to obtain well-defined architectures and to control polymer parameters. Among these systems is Cobalt-Mediated Radical Polymerization (CMRP ... [more ▼]

Controlled Radical Polymerization techniques have been developed to obtain well-defined architectures and to control polymer parameters. Among these systems is Cobalt-Mediated Radical Polymerization (CMRP), which is based on the reversible deactivation of the growing radical chains with a cobalt complex, the cobalt (II) bis(acetylacetonate). The interest of this system is not only due to its ability to control the polymerization of very reactive monomers such as vinyl acetate (VAc) and N-vinylpyrrolidone (NVP), but also its peculiar mechanism which exhibits two pathways depending on the polymerization conditions; a reversible termination process and a degenerative chain transfer mechanism. Furthermore, it has been showed that the Co-C bond strength and thus the polymerization are strongly influenced by the use of some additives, such as water, dimethylformamide, dimethylsulfoxide and pyridine, which coordinate the cobalt free site. In this presentation we report the use of a preformed alkyl-cobalt(III) adduct as initiator for the polymerization of various vinyl monomers of different reactivity (VAc, acrylonitrile,…) and on the effect of several ligands on their polymerization control. The preparation of novel block copolymers by CMRP will finally be presented. As a conclusion, cobalt-coordination appears today as a unique opportunity to adjust the Co-C bond strength and to push back the bounds of possibilities in terms of macromolecular engineering assisted by CMRP. [less ▲]

Detailed reference viewed: 89 (10 ULg)
See detailCobalt-mediated radical polymerization: an elegant tool of the synthesis of thermoresponsive N-vinylamide based copolymers
Kermagoret, Anthony; Mathieu, Kevin ULg; Poli, Rinaldo et al

Conference (2013, November 19)

Organometallic-Mediated Radical Polymerization (OMRP) is an emerging class of controlled radical polymerization based on the reversible deactivation of the growing radical chains by a metal complex. OMRP ... [more ▼]

Organometallic-Mediated Radical Polymerization (OMRP) is an emerging class of controlled radical polymerization based on the reversible deactivation of the growing radical chains by a metal complex. OMRP based on Co(acac)2 (CMRP) is very efficient for non-conjugated and reactive monomers such as vinyl esters or vinyl amides. Kinetics and theoretical investigations revealed the preponderance of an intramolecular cobalt chelation in the CMRP mechanism. The latter reinforces the cobalt-polymer bond at the polymer chain-end. The effects of the carbonyl donor power in the formation of the chalated structure, of the ring strain for the cyclic amides (lactams) and of hydrogen bonding for secondary vs. tertiary amides have been rationalized with help of DFT calculations. Such represents a unique opportunity to imporve the control of the polymerizations, especially for the synthesis of well-derined poly(N-vinhyl amide)s which sustain numerous applications. Because poly(N-)vinylcaprolactam)s (PNVCL) represent an important class of biocompatible and thermoresponsive material, a series of NVCL-based copolymers was synthezized via CMRP. Lower critical solution temperature (LCST) were tuned up and down by introduction of vinylacetamides or vinyl esters comonomers. CMRP also allowed the syntbhesis of new diblock copolymers having double thermoresponsive poroperties whereas the corresponding NVCL-based triblock copolymers were obtained by the cobalt-mediated raidical coupling (CMRC) method developed in our research center. The thermo-responsive properties and self-assembly behavior of these new di-and tri-block copolymers were studied by turbidimetry analysis and dynamic light scattering (DLS). [less ▲]

Detailed reference viewed: 43 (6 ULg)
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See detailLe Cobaye: un petit herbivore facile à nourrir dans des petites parcelles
Bindelle, Jérôme ULg; Picron, Pascale ULg

Article for general public (2012)

Detailed reference viewed: 62 (17 ULg)
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See detailCobblestone-like brain dysgenesis and altered glycosylation in congenital cutis laxa. Debre type
Van Maldergem, Lionel ULg; Yuksel-Apak, M.; Kayserili, H. et al

in Neurology (2008), 71(20), 1602-1608

Detailed reference viewed: 14 (0 ULg)
See detailCobham's theorem for fractals in R^n
Leroy, Julien ULg

Conference (2015, May)

Detailed reference viewed: 3 (1 ULg)