Characterization of polyethylene nascent powders synthesized with TpTiCl <inf>2</inf>(OR) catalysts

Abstract:

Different kinds of polyethylene and ethylene-1-hexene copolymers were synthesized with TpTiCl 2(OR) (Tp = hydrotris(pyrazolyl)borate; R = Et, i-Pr, n-Bu) catalysts with and without H 2. The polymers were characterized by 13C NMR, capillary viscosimetry or GPC, and DSC. The homopolymers showed properties characteristic of ultra-high molecular weight polyethylenes (UHMWPE) with linear structure and high density polyethylenes (HDPE) with molecular weights in the range of commercial grades under hydrogen atmosphere. The copolymers showed a 1-hexene incorporation up to 6 mol-%. Important differences in the thermal properties were observed between the first DSC (nascent powders) and the second DSC heatings (melt-crystallized samples), which evidenced the molecular weights influence on the melt-crystallized samples. Copyright © 2007 WILEY-VCH Verlag GmbH & Co. KGaA.

Año de publicación:

2007

Keywords:

• Polyethylene
• Nascent powders
• 1-hexene
• hydrogen transfer
• TpTiCl (OR) 2

Fuente:

scopus

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