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Silica‐supported metallocenes: effect of the preparation procedure on the morphology of polyethylene particles
Author(s) -
Lin ChiuHsun,
Sheu ChyiYang
Publication year - 2000
Publication title -
macromolecular rapid communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.348
H-Index - 154
eISSN - 1521-3927
pISSN - 1022-1336
DOI - 10.1002/1521-3927(20001001)21:15<1058::aid-marc1058>3.0.co;2-k
Subject(s) - polyethylene , catalysis , mixing (physics) , adsorption , morphology (biology) , materials science , chemical engineering , particle (ecology) , polymer chemistry , particle size , methylaluminoxane , fiber , metallocene , chemistry , polymer , composite material , organic chemistry , polymerization , physics , quantum mechanics , biology , engineering , genetics , oceanography , geology
Polyethylene (PE) particles are produced by a catalyst prepared by contacting a (C 4 H 9 Cp) 2 ZrCl 2 /MAO pre‐mixing solution with SiO 2 support. These particles have a large granular size and very few fine particles compared with those derived from a catalyst prepared by adsorption of (C 4 H 9 Cp) 2 ZrCl 2 onto methylaluminoxane modified SiO 2 . The amount of Al in the pre‐mixing catalyst has an important effect on its activity and the PE particle size distribution. The optimal concentration is about 30 wt.‐%. The PE particles produced using a pre‐mixing catalyst consist of globules with randomly oriented fiber structure on the surface, whereas those produced using adsorption catalysts have worm‐like fibrils protruding from the PE globule surface.