We synthesized organosoluble, thermoplastic elastomer/clay nanocomposites by making a jelly like solution of ethylene vinyl acetate containing 28% vinyl acetate (EVA-28) and blending it with organomodified montmorillonite. Sodium montmorillonite (Na+-MMT) was made organophilic by the intercalation of dodecyl ammonium ions. X-ray diffraction patterns of Na+-MMT and its corresponding organomodified dodecyl ammonium ion intercalated montmorillonite (12Me-MMT) showed an increase in the interlayer spacing from 11.94 to 15.78 Angstrom. However, X-ray diffraction patterns of the thermoplastic elastomer and its hybrids with organomodified clay contents up to 6 wt % exhibited the disappearance of basal reflection peaks within an angle range of 3-10degrees, supporting the formation of a delaminated configuration. A hybrid containing 8 wt % 12Me-MMT revealed a small hump within an angle range of 5-6degrees because of the aggregation of silicate layers in the EVA-28 matrix. A transmission electron microscopy image of the same hybrid showed 3-5-nm 12Me-MMT particles dispersed in the thermoplastic elastomer matrix; that is, it led to the formation of nanocomposites or molecular-level composites with a delaminated configuration. The formation of nanocomposites was reflected through the unexpected improvement of thermal and mechanical properties; for example, the tensile strength of a nanocomposite containing only 4 wt % organophilic clay was doubled in comparison with that of pure EVA-28, and the thermal stability of the same nanocomposite was higher by about 34degreesC. (C)2002 Wiley Periodicals, Inc.