Modification of montmorillonite with oligomeric amine derivatives for polymer nanocomposite preparation

Sodium montmorillonite (Na-MMT) was modified with oligomeric polyoxypropylene amine derivatives as well as simple amines by a cation exchange. For reference, commercial modified MMTs, Cloisite™ were analyzed in detail. The modifier content in OA-MMT as determined by TGA was found to be 4-40 wt.% and dependent on the structure of the modifier. The basal spacing of OA-MMT was strongly dependent on the structure and amount of the modifier. With the polyoxypropylenediamine of molecular mass 2000, the basal spacing of OA-MMT was enlarged up to 45.3 Å. The OA-MMT nanocomposites with polystyrene (PS) and poly(methyl methacrylate) (PMMA) were prepared by solution blending and in-situ polymerization, a large extent of exfoliation was obtained, together with thin packets of montmorillonite layers.