Polyethylene/MMT nanocomposites prepared by in situ polymerization using supported catalyst systems

A polyethylene/montmorillonite(MMT) nanocomposite was prepared by in situ polymerization method using MMT-supported methylaluminoxane(MAO) cocatalyst and/or Cp2ZrCl2 catalyst. The catalyst components had been supported on the unmodified MMT-Na and modified commercial product, Cloisite 25A. With XRD it was found that the layered silicate gallery of Cloisite 25A was exfoliated by incorporating MAO cocatalyst and zirconocene catalyst while the d-spacing of MMT-Na was less changed. The in situ polymerization of ethylene was carried out to prepare the nanocomposite by using the supported MMT, and the fully exfoliated product was obtained with Cloisite 25A. The decomposition temperature of the obtained nanocomposite increased up to 25 degrees C, but the melting temperature was not improved much. (c) 2005 Elsevier Ltd. All rights reserved.