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Study of the influence of the reaction parameters on the composition of the metallocene‐catalyzed ethylene copolymers using temperature rising elution fractionation and 13 C nuclear magnetic resonance
Author(s) -
Barrera Griselda,
Santos Raquel,
Portal Luciana,
Silva Da,
Liberman Susana,
Arli Adilson,
Silva Da,
Quijada Raúl
Publication year - 2002
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.10284
Subject(s) - comonomer , ethylene , copolymer , 1 hexene , gel permeation chromatography , polyethylene , post metallocene catalyst , materials science , elution , metallocene , polymer chemistry , differential scanning calorimetry , fractionation , catalysis , analytical chemistry (journal) , chemistry , chromatography , polymerization , organic chemistry , polymer , composite material , physics , thermodynamics
Abstract Polyethylene copolymers prepared using the metallocene catalyst rac ‐Et[Ind] 2 ZrCl 2 were fractionated by preparative Temperature Rising Elution Fractionation (p‐TREF) and characterized by 13 C nuclear magnetic resonance (NMR), differential scanning calorimetry (DSC), and gel permeation chromatography (GPC) to study the heterogeneity caused by experimental conditions. Two ethylene–1‐hexene copolymers with different 1‐hexene content and an ethylene–1‐octene copolymer all obtained using low (1.6 bar) ethylene pressure were compared with two ethylene–1‐hexene copolymers with different 1‐hexene content obtained at high ethylene pressure (7.0 bar). Samples obtained at low ethylene pressure and with low 1‐hexene concentration in the reactor presented narrow distributions in composition. Samples prepared with high comonomer concentration in the reactor or with high ethylene pressure showed an heterogeneous composition. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 155–163, 2002; DOI 10.1002/app.10284