Rheological characterization of molten ethylene-\#a\olefin copolymers synthesized with Et[Ind]2ZrCl2/MAO catalyst

• Published in: Polymer (Guilford) Vol. 42; no. 22; pp. 9269 - 9279
• Main Authors: Villar, M A, Failla |h M. D., Quijada |h R., Mauler |h R. S., Valles |h E. M., Galland |h G. B., Quinzani |h L. M.
• Format: Journal Article
• Language: English
• Published: 01.10.2001
• ISSN: 0032-3861

The linear viscoelastic behaviour of copolymers of ethylene with 1-hexene, 1-octene, 1-decene and 1-octadecene prepared with Et[Ind]2 ZrCl2/MAO is analyzed. The copolymers with alpha-olefin concentration greater than approximately 14 mol% have the simple rheological behaviour with temperature that may be associated with linear polyethylenes with short chain branches. On the other hand, the polymers having comonomer concentration lower than approximately 14 mol% are thermo-rheologically complex materials. The rheological behaviour of these copolymers may not be explained solely by the presence of long chain branching. A dendritic-like molecular structure with branches-on-branches has to be considered to explain the complexity observed in the case of the ethylene copolymers with low comonomer concentration and ethylene homopolymer. The complex chain structure would be the result of the incorporation of branched macromonomers in the polymers produced by single-site catalysts. (Original abstract - amended)