Characterization of polyethylene synthesized by zirconium single site catalysts

• Published in: Applied petrochemical research Vol. 4; no. 1; pp. 79 - 84
• Main Authors: Alsaygh, Abdulhamid A., Al-hamidi, Jehan, Alsewailem, Fares D., Al-Najjar, Ibrahim M., Kuznetsov, Vladimir L.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-05-2014; Springer Nature B.V
• Subjects: Catalysis; Catalysts; Chemistry; Chemistry and Materials Science; Decomposition reactions; Energy Systems; Equivalence; Ethylene; Industrial Chemistry/Chemical Engineering; KACST Forum; Molecular structure; Nanochemistry; Nanotechnology and Microengineering; Polyethylenes; Polymerization; Polymers; X-ray diffraction; Zirconium; Polyethylene; Zirconium; Single site catalysts
• ISSN: 2190-5525; 2190-5525
• DOI: 10.1007/s13203-014-0053-2

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 ZrCl
4
(THF)
2
, and tested for ethylene polymerization reaction at different conditions. Catalyst productivities were found to be high, in the range of 29.5 × 10
3
 kg/mole·Zr·h to 2.3 × 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.
13
C 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 (
Pnam
) and carbon–carbon interatomic distance of 0.154061 nm and the C–C–C angle of 112.192°.