title: Grafting of swelling clay materials with 3-aminopropyltriethoxysilane.
abstract: The grafting reaction between a trifunctional silylating agent and two kinds of 2:1 type layered silicates was studied using FTIR, XRD, TGA, and 29Si CP/MAS NMR. XRD patterns clearly indicate the introduction of 3-aminopropyltriethoxysilane (gamma-APS) into the clay interlayer. In the natural montmorillonite, gamma-APS adopts a parallel-bilayer arrangement, while it adopts a parallel-monolayer arrangement in the synthetic fluorohectorite. These different silane arrangements have a prominent effect on the mechanism of the condensation reaction within the clay gallery. In natural montmorillonite, the parallel-bilayer arrangement of gamma-APS results in bidentate (T2) and tridendate (T3) molecular environments, while the parallel-monolayer arrangement leads to monodentate (T1), as indicated by 29Si CP/MAS NMR spectra. This study demonstrates that the silylation reaction and the interlayer microstructure of the grafting products strongly depend on the original clay materials.
authors.affiliation: Laboratoire des Matériaux Macromoléculaires/IMP, UMR 5627 - IMP, INSA Lyon, Bât. Jules Verne, 20 avenue A. Einstein, 69621 Villeurbanne, France.
authors.forename: Hongping
authors.initials: H
authors.lastname: He
authors.forename: Jannick
authors.initials: J
authors.lastname: Duchet
authors.forename: Jocelyne
authors.initials: J
authors.lastname: Galy
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Gerard