supported catalyst prepared by first contacting the thus-prepared MgCl 2 with a
solution of BI
iPr2 P FeCl 2 and then with 500 equivalents of TEA is high
(0.6–2 ton g Fe
À1 h
À1 ). The bulk density (to a high maximum of 390 g L
À1 ) of the
polyethylene increases with the extent of dealcoholization of the MgCl 2 support.
Moreover, the temperature stability of the catalyst increased substantially by
supporting, and high activities (2.5 ton PE g Fe
À1 bar
À1 h
À1 ) were observed for
more than 30 min (or even over hours at 70
C and 10 bar of ethylene pressure).
The polymerization rate has an increasing and decreasing phase if dealcoholization
is incomplete. The molecular weights (M w ) are up to the range of UHMWPE, i.e.,
500 kg mol
À1 (PDI 10.20). The melting temperature of 136–137
C is consistent
with linear PE.
Dispersed activated MgCl 2 from Mg and butyl chloride is also useful as a
substrate for iron catalysts [48]. The BI
Me2 P FeCl 2 may be directly immobilized
onto this MgCl 2 . Addition of TIBA at a relatively low ratio of Al/Fe ¼ 500/1 in
Fig. 5 Polymerization in zeolite SBA-15 channels. SEM images show formation of PE in
bundles [73]
354
R.S.A. Meyer and G.A. Luinstra