Abstract: Polymer-clay nanocomposites prepared by reacting two or more layered materials, e.g. nanoclays, with an onium cation which is sorbed into the adjacent nanoclay layers. The Nanomer is subsequently dispersed into a melt-processible polymer matrix. The preferred polymers are nylon MXD6 and its co-polymers. The invention also relates to processes for preparing a nanocomposite and articles produced from a nanocomposite. The polymer-clay nanocomposite improves gas permeability of panels, sheets, film, film laminates and multilayer bottles.