چكيده لاتين :
Bis(cyclopentadienyl) zirconium dichloride (CP2ZrCI2) as a homogeneous metallocene
catalyst was manufactured in laboratory scale under highly controlled conditions.
Ethylene polymerization was carried out using this catalyst while, methylaluminoxane
(MAO) was used as a cocatalyst. Activity of 5759 gPE/mmol Zr.h at [AII/[Zr]
molar ratio of 770/1 was obtained, Polymer yield was increased with increasing in [A1I/[Zr]
ratio to a limiting value. Addition of hydrogen as a chain transfer agent up to 120 cm3/L
solvent, increased the activity of the catalyst. Polymerization was carried out at monomer
pressure of 1 to 5 atm, and temperature of 40DC to BODe. Polymerization activity was
increased with increasing temperature to 60DC and slightly decreased with more increase
in temperature. Upon the addition of catalyst a sudden increase of 10DC in temperature
was observed, particularly when polymerization temperature was higher than 50DC. This
increase could be due to high rate of polymerization which at high temperature could
affect catalyst activity. Monomer pressure up to 2 atm increased the productivity of the
catalyst. Increase in [AI]/[Zr] ratio, polymerization temperature and H2 concentration
decreased Mv of polymer obtained, Melting point of polymer also decreased with increasin(;
j [AI]I[Zr] ratio. Density of obtained polyethylene was 0,940-0,950 g/cm3, T
9
of one of
the polymer samples was determined to be 99,9DC.
