Copolymerization and characterization of ethene-1-hexene copolymers prepared by using the (Me5Cp)2ZrCl2-MAO catalyst system

Autor: Jörg Kressler, H. Menge, Peter Arends, Tammo J. Menke, Jürgen Giesemann, Sven Rudolph
Rok vydání: 1999
Předmět:
Zdroj: Journal of Applied Polymer Science. 74:439-447
ISSN: 1097-4628
0021-8995
DOI: 10.1002/(sici)1097-4628(19991010)74:2<439::aid-app27>3.0.co;2-h
Popis: It is demonstrated that the catalyst system bis(pentamethylcyclopentadienyl)-zirconium dichloride (Me5Cp)2ZrCl2–methylaluminoxane (MAO) is able to produce random copolymers of ethene and 1-hexene. The 1-hexene incorporation in the copolymers is extremely small. Even in the case of a molar ratio of [ethene] to [1-hexene] of 1/20 in the monomer feed, only 1.4 mol % 1-hexene are incorporated according to 13C nuclear magnetic resonance (NMR) spectra. Nevertheless, the physical properties of the random copolymers change significantly in this small range of 1-hexene incorporation, from a high-density polyethene to a linear low-density polyethene. Thus, the melting temperature, the degree of crystallinity, the density and lamella thickness, and the long period of the alternating crystalline and amorphous regions decrease with increasing 1-hexene content in the random copolymers. Blends of high-density polyethene prepared with the system (Me5Cp)2ZrCl2–MAO and an elastomeric random copolymer of ethene and 1-hexene are phase-separated and show good compatibility, as demonstrated by transmission electron microscopy. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 439–447, 1999
Databáze: OpenAIRE
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