Supported metallocene catalysis for in situ synthesis of high energy density metal oxide nanocomposites

The 0-3 metal oxide-isotactic polypropylene nanocomposites are synthesized via in situ propylene polymerization using the C-2-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 C-13 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 approximate to 10(-6) to 10(-9) A/cm(2), permittivities as high as 6.1, and breakdown strengths of approximate to 4 MV/cm. Energy densities are estimated to be as high as 9.4 J/cm(3).