Modification of sodium montmorillonite: dependence of silylation on premixing process

Document Type : Research Paper

Authors

1 Chemical, Polymer & Petrochemical Technology Development Research Division, Research Institute of Petroleum Industry (RIPI), P.O. Box 14665-137, Tehran, Iran

2 Chemical, Polymer & Petrochemical Technology Development Research Division, Research Institute of Petroleum Industry (RIPI), Tehran, Iran

Abstract

In the present research, 3-aminopropyltriethoxysilane (APTES) was used for modification of sodium montmorillonite (Na+-MMT) in an aqueous medium. The effects on the basal spacing of Na+-MMT upon the premixing process with different mixing techniques were examined in details. The resultant products (S-Mts) were characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA) and Fourier transform infrared (FTIR) spectroscopy. For monitoring of the grafting process, FTIR was used; while the percentage of the loaded silane was calculated by TGA. XRD measurements were carried out to evaluate the increase of the d-spacing. The amount of the grafted silane increases with choosing the suitable premixing process such as the mechanical mixer and homogenizer. The same beneficial effects were also observed on d-spacing, as it increases by using the mechanical mixer and homogenizer. This study demonstrates that the degree of grafting and d-spacing of the grafted products strongly depends on the mixing process before the silylation reaction. This is very important for synthesis and application of polymer nanocomposites containing silylated layered silicates minerals.

Keywords