Bruno A.,National Graduate School of Chemistry, Montpellier
Macromolecules | Year: 2010
Controlled radical polymerizations (CRP) were pioneered in the late 1970s. Since then, tremendous investigations have been developed, especially from mid-1990s which generated much enthusiasm on CRP. However, the extraordinary scientific development of CRP contrasts with the limited number of commercially available products derived from these technologies. But, for fluoropolymers, the situation is different since iodine transfer polymerization of fluoroalkenes led to commercially available thermoplastic elastomers as soon as 1984. A browse or CRP of fluorinated monomers is presented and is classified into three families: (i) the CRP of fluorine-containing styrenic monomers mainly occur from nitroxide-mediated polymerization (NMP) or by atom radical transfer polymerization (ATRP); (ii) that of fluorinated (meth)acrylic monomers from NMP, ATRP, and in the presence of iniferters; and finally (iii) fluoroalkenes (which is a real challenge since these monomers are gaseous) can be (co)polymerized by iodine transfer polymerization or by processes that required either borinates or xanthates (MADIX). A peculiar interest lies in the CR copolymerization of fluoroalkenes with other comonomers (such as vinylidene fluoride, chlorotrifluoroethylene, 3,3,3-trifluoropropene, hexafluoropropylene, perfluoromethyl vinyl ether, or α-trifluoromethacrylic acid) in the presence of either xanthates, borinates, or iodo compounds. These technologies enable one to generate copolymers that exhibit well-defined architectures, such as telechelic, block, and graft copolymers. Merits and limitations of CRP of F-monomers are also reported. Finally, this Perspective is illustrated by several properties and applications of these fluorinated copolymers (such as surfactants, thermoplastic elastomers, fuel cell and ultrafiltration membranes, dielectrical polymers, optical storage devices, or polycondensates, the fluorinated segments of which bring softness and thermal stability). Hence, CRP can be regarded as a revolutionary method to produce precisely controlled, next-generation specialty fluorinated (co)polymers. © 2010 American Chemical Society.
Auvergne R.,National Graduate School of Chemistry, Montpellier |
Caillol S.,National Graduate School of Chemistry, Montpellier |
David G.,National Graduate School of Chemistry, Montpellier |
Boutevin B.,National Graduate School of Chemistry, Montpellier |
And 2 more authors.
Chemical Reviews | Year: 2014
The works undertaken to obtain either partially or fully biobased epoxide materials are studied. The reaction between the phenate ion and ECH 2 reveals two competitive mechanisms, one-step nucleophilic substitution with cleavage of the C-Cl bond and a two-step mechanism based on ring opening of ECH (2) with ArO- (1') followed by intramolecular cyclization (SNi) of the corresponding alcoholate, containing one atom of chlorine in the β-position, formed in situ. Depending on the substituent position or nature in the phenol, it takes 6-20 h at reflux or 24-26 h at room temperature to complete the reaction. The reaction of ECH with an alcohol is more difficult, with many side reactions, since this reaction generates new alcohol groups with similar pKa values which are able to react with the epoxy group of ECH, thus leading to its homopolymerization. Epoxies are able to react with (meth)acrylic acid to give formulations for coating applications or vinyl ester monomers and networks after radical polymerization.
Boschet F.,National Graduate School of Chemistry, Montpellier |
Ameduri B.,National Graduate School of Chemistry, Montpellier
Chemical Reviews | Year: 2014
Quasi-exhaustive data on the synthesis, homopolymerization, and copolymerization of Poly(chlorotrifluoroethylene) (PCTFE) with an emphasis on the resulting (co)polymers including their kinetics is reported. PCTFE is a nonflammable polymer with excellent chemical resistance, it has both excellent barrier and electrical properties. PCTFE has two main limitations. First, the homopolymer is insoluble in most common organic solvents, and second it is difficult to cross-link due to the absence of a functional group. The telomerization of CTFE with a wide range of different chain transfer agents (or telogens) led to many documented investigations for the synthesis of low molecular weight polymers. CTFE copolymers also contain a low amount of CTFE that is always less reactive and thus less incorporated, and hence this leads to poor mechanically and thermally stable materials. In the case of the radical copolymerization of CTFE with vinyl ethers, which led to alternating copolymers, many of the resulting products have been developed for the coatings and paints market.
Agency: European Commission | Branch: FP7 | Program: MC-IRSES | Phase: FP7-PEOPLE-2010-IRSES | Award Amount: 256.90K | Year: 2011
The passage of electric current through interfaces between media with different electrochemical properties is accompanied by changes in the solution composition close to the interfaces (concentration polarization). Another phenomenon occurring at solid-liquid interfaces is the charge separation and formation of (equilibrium and non-equilibrium) double electric layers. Subject to external and/or spontaneously arising electric fields and ion-composition gradients, the space charges give rise to volume-transfer phenomena. Their intensity is strongly dependent on the ion composition of the liquid phase, which can change considerably close to current-polarized interfaces. This is one of the mechanisms of coupling between the ion- and volume-transfer phenomena in heterogeneous systems. At the same time, the space-charge-related volume transfer can strongly modify the solution composition close to polarized interfaces via convective transfer of solutes. This is another mechanism of coupling between the phenomena of interest. The interplay of these two mechanisms gives rise to a number of non-linear, non-1D and non-stationary phenomena. Their modeling is difficult but important for the optimization of applications in clean energy, advanced water treatment, micro-analysis, and so on. Because of complexity of the objects involved, such a model cannot be formulated from first principles and has to use input parameters determined experimentally. Therefore, fundamental experimentation is an indispensable constituent part of the modeling effort. Important elements of this model and/or corresponding fundamental experimentation have been developed in the previous studies of the Proposers. The purpose of this project is to facilitate the knowledge transfer between them to make possible further development and integration of these elements into a self-consistent and comprehensive model. Its utility will be validated via optimization of several practically-relevant systems/processes.
National Graduate School of Chemistry, Montpellier and Arkema | Date: 2012-11-30
The invention relates to a method of preparing a fluorinated copolymer, comprising a step of copolymerization of a fluorinated monomer (of the vinylidene fluoride type) with an -trifluoromethacrylic acid monomer or derivative of -trifluoromethacrylic acid, in the presence of a xanthate or trithiocarbonate compound. The invention also relates to copolymers obtained by this method as well as block copolymers comprising a copolymer block prepared according to this method.
Agency: European Commission | Branch: H2020 | Program: MSCA-RISE | Phase: MSCA-RISE-2015 | Award Amount: 238.50K | Year: 2016
The PhotoFluo project consists in a consortium of three teams (two from Europe and one from Canada) committed to work for developing novel fluoropolymers suitable for optical and electronic devices, membranes for fuel cells and Li batteries, microfluidics, and biomaterials. This ambitious goal will be achieved starting from designing new perfluoropolyalkylether building blocks (PFPAE) improving safety (not bioaccumulative like perfluoroalkylics) and having chemical inertness, flexibility in a wide temperature range, very low refractive index and wettability. PFPAE will be chain extended to tune final properties; exploiting OH functionalities, these precursors will be functionalized to make telechelic macromonomers for suitable crosslinking (via both radical and ionic processes). The polymers will be synthesized by photoinduced polymerization, chosen as an efficient and eco-friendly process: the polymer formation is fast (no more than minutes compared to hours requested by thermal processes), is solvent free, is carried out at room temperature consuming low amount of energy, permits spatial resolution, as it mainly occurs in the illuminated areas. After obtaining an original portfolio of PFPAE polymers, they will be fully characterized and tested in view of innovate applications. The project is conducted by research groups with a relevant scientific record in the fields: (i) fluorochemistry (TWU, Canada), (ii) photopolymerization (iii) polymer science (POLITO, Italy and ENSCM, France). The combination of expertises makes the objective feasible. For the implementation of the program, 24 secondments are planned to exploit the complementarities of the different expertises of each groups, to share them and to reinforce young researchers career. The project includes a strong dissemination plan to report on the results, not only to the scientific community, but also to potential users and non-specialized audience.
French National Center for Scientific Research, National Graduate School of Chemistry, Montpellier and Montpellier University | Date: 2013-07-08
The invention concerns a mono- or polyfunctional polysilylated organosilane compound, and the method for preparing same.
French National Center for Scientific Research, University Sidi Mohammed Ben Abdellah and National Graduate School of Chemistry, Montpellier | Date: 2013-02-26
A method for the creation of a carbon-carbon (CC) bond or of a carbon-heteroatom (C-HE) bond includes reacting a compound carrying a leaving group with a nucleophilic compound carrying a carbon atom or a heteroatom (HE) capable of replacing the leaving group, thus creating a CC or C-HE bond, in which process the reaction is carried out in the presence of an effective amount of a catalytic system comprising at least one copper/butadienylphosphine complex.
Arkema and National Graduate School of Chemistry, Montpellier | Date: 2013-04-25
The invention concerns a method for preparing block copolymers, comprising a step of controlled free-radical copolymerisation of trifluoroethylene with at least one additional monomer, different from trifluoroethylene, in the presence of a chain transfer agent, said chain transfer agent being a xanthate compound, a trithiocarbonate compound or a monoiodide compound. The invention also concerns the block copolymers likely to be obtained by this method.
French National Center for Scientific Research, University of Parma and National Graduate School of Chemistry, Montpellier | Date: 2015-04-22
The present invention relates to a composition comprising an effective amount of urolithin A, urolithin B, urolithin C, urolithin D, or a combination thereof, for the stimulation of insulin secretion, and to the use of a compound chosen among urolithin A, urolithin B, urolithin C, urolithin D, or a combination thereof, for the stimulation of insulin secretion. The present invention also relates to a composition comprising an effective amount of urolithin B, urolithin C, urolithin D, or a combination thereof, for the treatment or the prevention of diabetes mellitus, and to the use of a compound chosen among urolithin B, urolithin C, urolithin D, and a combination thereof, for the treatment or the prevention of diabetes mellitus.