Moulay S.,CNRS Macromolecular Chemistry and Physics Laboratory
Progress in Polymer Science (Oxford) | Year: 2010
Poly(vinyl chloride) (PVC) has continued to be a research topic in polymer science since its discovery in the early 19th century. Its internal structural defects, which stem from its direct manufacture (via free radical polymerization), heighten its peculiarities, including its thermal instability. Apart from the addition of organic and inorganic thermal stabilizers, improved chemistry in the formation of PVC has been proposed to alleviate some of its intrinsic limiting properties. This chemistry, mainly via the chemical transformations of this polymeric material, has been broadened by widespread ongoing research. The so-called anomalous or labile chlorine atoms, that is, the tertiary and allylic chlorines, and the normal secondary ones coupled with a varying content of carbon-carbon double bonds, have been subjected to numerous chemical modifications. The latter were undertaken not only for routine chemical reactions, but also for the sake of enhancing the properties, understanding PVC-related phenomena, and the use of PVC in specific applications. The different reactions on PVC, basically dechlorination, involved nucleophilic and radical substitutions, elimination or dehydrochlorination, and grafting polymerizations via cationic and free radical pathways (old processes or new ones, ATRP and LCRP). Leading and attractive applications of the chemically modified PVCs were ion-selective electrode membranes, membrane sensors, and biomedical devices. In this paper, an account of many of the chemical modifications of PVC based on reports over the last decade is delineated, along with related applications. These modifications are presented according to the bond formed (CPVC-X) between the PVC carbon CPVC and the atom X (X = N, O, S, Hal) of the modifying molecule. © 2009 Elsevier Ltd. All rights reserved.
Boyer C.,University of New South Wales |
Whittaker M.R.,University of New South Wales |
Nouvel C.,University of New South Wales |
Nouvel C.,CNRS Macromolecular Chemistry and Physics Laboratory |
Davis T.P.,University of New South Wales
Macromolecules | Year: 2010
This paper describes a new approach for the synthesis of hollow functional polymer nanocapsules, which exploits gold nanoparticles as sacrificial templates. Two different functional diblock polymers have been coassembled on the gold nanoparticles prior to gold removal. The block polymers (made by RAFT polymerization) consisted of a biocompatible polymer segment, either (poly(oligoethylene glycol) acrylate, P(OEG-A), or poly(hydroxylpropylacrylamide), P(HPMA) and a cross-linkable segment comprised of an alternating copolymer of styrene (Sty) and maleic anhydride (MA), (Sty-alt-MA). The block copolymers were assembled onto the GNP surfaces using a grafting "onto" methodology exploiting the high affinity of the RAFT end-groups for the gold surface. The anhydride group was utilized to cross-link the polymer layer. Finally, the gold cores were removed using aqua regia without affecting the integrity of the polymers chains or the nanocapsules. All reaction and assembly steps were characterized by employing a range of techniques, such, as TEM, XPS, ATR-FTIR, DLS, and UV-visible spectroscopy. © 2010 American Chemical Society.
Sadtler V.,University of Lorraine |
Rondon-Gonzalez M.,University of Lorraine |
Acrement A.,University of Lorraine |
Choplin L.,University of Lorraine |
Marie E.,CNRS Macromolecular Chemistry and Physics Laboratory
Macromolecular Rapid Communications | Year: 2010
This study reports the first PEO-coated polymer nanoparticles synthesis by miniemulsion polymerization of nano-emulsions prepared by the low-energy emulsification method called EIP. The surfactant used was Brij 98, a PEO based non ionic commercial surfactant. The partial phase diagram of the system water/Brij 98/styrene was first determined. The Emulsion Inversion Point technique was then used on the water/Brij 98/styrene system to the formation of styrene-in-water nano-emulsions. After miniemulsion polymerization, particle sizes as low as 36 nm were obtained. To the best of our knowledge, this method had not been used for polymerizable system up to now. (Figure Presented) © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Legrand B.,CNRS Macromolecular Chemistry and Physics Laboratory |
Andre C.,Max Mousseron Institute of Biomolecules |
Wenger E.,University of Lorraine |
Didierjean C.,University of Lorraine |
And 4 more authors.
Angewandte Chemie - International Edition | Year: 2012
BAC for more: A constrained bicyclic building block with urea linkages is an efficient combination for the formation of a highly rigid helical system. This type of bicyclic amino carbamoyl (BAC) foldamer was studied both in solution (see scheme) and in the solid state. A robust H-bond (dotted line) network was found between the carbonyl oxygen atoms (red) and the amino groups (dark blue) within the helix. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Collin D.,Charles Sadron Institute |
Covis R.,Charles Sadron Institute |
Allix F.,CNRS Macromolecular Chemistry and Physics Laboratory |
Jamart-Gregoire B.,CNRS Macromolecular Chemistry and Physics Laboratory |
Martinoty P.,Charles Sadron Institute
Soft Matter | Year: 2013
The liquid to organogel transition of solutions containing new organogelator molecules of the amino-acid type is studied using rheological and differential scanning calorimetry (DSC) techniques. This paper describes the formation of the organogel as a function of the temperature for various concentrations of the organogelator molecules, and the mechanical properties of the organogel as a function of concentration, frequency, thermal history and aging. We show that the organogel is not a physical gel, but a jammed suspension. The viscoelastic behavior at different extents of the jamming can be scaled onto a single master curve describing the growth of a solid network in a background fluid. The formation of the solid network exhibits a critical-like behavior that is reminiscent of elasticity percolation. Four characteristic temperatures have been identified: the temperature at which the clusters begin to form, the transition temperature between the liquid and the organogel, the onset temperature of the percolation-like behavior of the solid component of the system and the temperature at which the solid component has a pure elastic response. The comparison between the rheological measurements and the DSC measurements shows that the rheological measurements detect the fluid-to-organogel transition, whereas DSC detects the molecular associations in the material, which are at the origin of the formation of the clusters. The two temperatures differ significantly from each other and their difference gives the temperature range where the clusters are crowding. This study demonstrates for the first time that an organogel is not a physical gel, as it is currently believed, but a jammed suspension. © 2013 The Royal Society of Chemistry.