Various cyclic amidinium cations were used to exchange intergallery sodium cations of water-swellable fluorohectorite in order to produce novel families of organic/inorganic hybrid materials. Oligomeric cyclic amidinium cations, such as mono(imidazolinium)terminated oligostyrene, oligostyrene-co-oligo(acrylonitrile), and oligo(methyl methacrylate) with number-average molecular masses around 3000 g/mol afforded effective exfoliation during melt processing. Morphology and dynamic mechanical properties were measured as a function of silicate content and silicate modification.