Characterization of polyethylene synthesized by zirconium single site catalysts

New non-metallocene, bridged-zirconium center catalysts were prepared by Schiff base condensations reaction of two equivalents of appropriate 2-hydroxybenzaldehyde with one equivalent of 4,4'-methylene bis(2-methylcyclohexylamine), and subsequent metathesis reaction with ZrCl4(THF)(2), and tested for ethylene polymerization reaction at different conditions. Catalyst productivities were found to be high, in the range of 29.5 x 10(3) kg/mole.Zr.h to 2.3 x 10(3) kg/mole.Zr.h, dependents on the polymerization condition. The molecular weight of the product, i.e. polyethylene, varied from 397,000 to 988,000. C-13 NMR study of the polymers indicate that fraction of branches and end groups percentage range from 0.01 to 0.55. X-ray diffraction analysis showed that polyethylene samples had highly crystalline structure within the orthorhombic space group (P-nam) and carbon-carbon interatomic distance of 0.154061 nm and the C-C-C angle of 112.192 degrees.