Polyethylene (PE)/clay nanocomposites were prepared directly from Na+ montmorillonite by a melt intercalation technique, using hexadecyl trimethyl ammonium bromide (C16) as a reactive compatibilizer. Three other polymer-clay nanocomposites were also prepared by this new technique. Their structures were characterized by X-ray diffraction and transmission electron microscopy. The mechanism of this new method was studied. (C) 2003 Wiley Periodicals, Inc.