Surface and Intercalation Chemistry of Polycarboxylate Copolymers in Cementitious Systems

Autor: Robert J. Flatt, Jean-Baptiste d'Espinose de Lacaillerie, Claire Giraudeau, Zied Souguir, André Nonat
Přispěvatelé: Laboratoire de Physico-Chimie des Polymères et des Milieux Dispersés ( PPMD ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -ESPCI ParisTech-Centre National de la Recherche Scientifique ( CNRS ), Laboratoire Interdisciplinaire Carnot de Bourgogne ( LICB ), Centre National de la Recherche Scientifique ( CNRS ) -Université de Bourgogne ( UB ), SIKA TECHNOLOGIES AG, SIKA, Birot, Agnès, Laboratoire de Physico-Chimie des Polymères et des Milieux Dispersés (PPMD), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Laboratoire Interdisciplinaire Carnot de Bourgogne (LICB), Université de Bourgogne (UB)-Centre National de la Recherche Scientifique (CNRS)
Jazyk: angličtina
Rok vydání: 2009
Předmět:
Zdroj: Journal of the American Ceramic Society
Journal of the American Ceramic Society, Wiley, 2009, 92 (11), pp.2471-2488
HAL
ISSN: 0002-7820
1551-2916
Popis: International audience; The Ca–Al-layered double hydroxide, the so-called AFm phase, is a product of cement hydration. It is shown that the interaction of this phase with anionic polycarboxylate ether (PCE)-based dispersant polymers is not a simple adsorption but a more complex intercalation phenomenon leading to the transient sequestration of the PCE within the AFm crystallites. As a result, part of the PCE is immobilized, forming a layered organo-mineral composite, and does not play its role of a dispersing agent. This article presents, along general considerations on the links between cement chemistry and rheology, a detailed investigation of the formation, structure, and stability of a pure poly(methacrylate- g-PEO)/hydrocalumite composite obtained by coprecipitation. The predictions of scaling laws derived from models of conformation of comb copolymers in solution were tested against small-angle X-ray diffraction, transfer of populations by double-resonance nuclear magnetic resonance, and small-angle neutron scattering experimental results. A model of adsorbed polymers in a configuration of a flexible chain of hemispheric cores is proposed and appears to be compatible with the observed interlayer spacings in the range of several nanometers. Finally, these phases are shown to persist for several hours in the presence of sulfate ions.
Databáze: OpenAIRE
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