s Sepehri - Polymer department, Amirkabir University of Technology, ۴۲۴ Hafez Ave,Tehran, Iran
M Rafizadeh - Polymer department, Amirkabir University of Technology
M Hemmati - ۳Polymer department of Research institute of Petroleum of Iran
H Buhendi - Iran Polymer & petrochemical Institute, ۱۵th km of Karaj highway, Tehran,

Silylation of clay mineral surfaces has attracted much attention due to their extensive applications in materials science and environmental engineering. Cloisite Na+ was modified with trichlorovinylsilane and dimethylchlorovinylsilane in order to replace the silanol groups of the Cloisite Na+. Grafting was confirmed by FTIR, XRD and TGA. The effects ofconcentration of silane and presence of NaHCO3 in the reaction media on grafting amount andbasal spacing was studied. When NaHCO3 is present the reaction was mostly done on the edge silanol groups. The most grafting amount is obtained in silylation with 4mmol/g of monofunctional silane. These modified nanosilicates can later be used in preparation of water soluble nanocomposites, in that they have vinyl groups which could participate in in situ preparation of these nanocomposites

Organosilane, Na-MMT, Silylation, Grafting