Supported Metallocene Catalysis for In Situ Synthesis of High Energy Density Metal Oxide Nanocomposites

Abstract

The 0−3 metal oxide−isotactic polypropylene nanocomposites are synthesized via in situ propylene polymerization using the C2-symmetric metallocene catalyst dichloro[rac-ethylenebisindenyl]zirconium(IV) (EBIZrCl2) immobilized on methylaluminoxane (MAO)-treated barium titanate (BaTiO3) or titanium dioxide (TiO2) nanoparticles. The composite materials are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and 13C nuclear magnetic resonance (NMR) spectroscopy. It is shown that the nanoparticles are homogeneously dispersed in the polyolefin matrices. Electrical measurements reveal nanocomposite leakage current densities of ∼10-6 to 10-9 A/cm2, permittivities as high as 6.1, and breakdown strengths of ∼4 MV/cm. Energy densities are estimated to be as high as 9.4 J/cm3.