Preparation of Nanosilica/Polynorbornene Nanocomposite by Covalently Immobilized Silica-Supported Acetylacetonate Palladium(II) Dichloride Catalyst

Covalently immobilized silica-supported acetylacetonate dichloride palladium(II) precatalyst is prepared by the reaction of silica particles grafted acetylacetonate ligand further exchange with [Et4N](2)PdCl4. The silica-supported catalyst is used in slurry polymerizations of norbornene (NB) to afford a highly productive NB addition polymerization system in combination with B(C 6 F 5) 3 cocatalyst. It exhibits productivity of 84 kg of PNB (mol Pd)(-1) h(-1) at the initial activity, and the catalyst deactivation kinetics in the early stage of polymerization are fitted well by the first-order deactivation kinetics. The obtained vinyl-type polynorbornene is confirmed to be nanosilica hybrid PNB nanocomposite by SEM, TEM with an energy dispersive spectrometer, TGA, and XRD.