Polymer Bulletin, Vol.64, No.3, 221-231, 2010
Polypropylene nanocomposites using metallocene catalysts supported on commercial organophilic clays
In this work, different organophilic clays were employed as supports for the preparation of heterogenized metallocene catalysts to be evaluated for propylene polymerization. The supports employed were Viscogel B8, Claytone HY and Cloisite 15A. These supports were chemically pre-treated with methylaluminoxane (MAO) and then impregnated with SiMe2(2-Me-Ind)(2)ZrCl2 complex. The prepared catalysts performed much worse than the homogeneous precursor system. Those organoclays, as well as the prepared metallocene catalysts, were analyzed by X-ray diffractometry (XRD), showing the displacement and broadening of the clay peak to lower angles. The polymers were also characterized by XRD, infrared absorption spectrometry (FTIR) to determine the isotactic index, by thermogravimetric analysis (TGA) to determine the degradation temperatures, by differential scanning calorimetry (DSC) to determine the thermal characteristics of the polypropylene produced, and by transmission electron microscopy (TEM) to examine the morphology of the materials obtained.