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Measurement and mathematical modeling of molecular weight and chemical composition distributions of ethylene/ α ‐olefin copolymers synthesized with a heterogeneous Ziegler‐Natta catalyst
Author(s) -
da Silva Filho Adilson A.,
Soares João B. P.,
Galland Griselda B. de
Publication year - 2000
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/1521-3935(20000801)201:12<1226::aid-macp1226>3.0.co;2-w
Subject(s) - fractionation , gel permeation chromatography , catalysis , polyethylene , molar mass distribution , crystallization , ethylene , ziegler–natta catalyst , olefin fiber , chemical composition , natta , chemistry , polymer chemistry , copolymer , chemical engineering , polymerization , elution , materials science , organic chemistry , chromatography , polymer , engineering
The distributions of molecular weight and chemical composition of two linear low‐density polyethylene resins synthesized with Ziegler‐Natta catalysts were analyzed with several microstructural characterization techniques and the results were used to investigate the nature of the active site types present on the catalyst. Deconvolution of the molecular weight distribution measured by gel permeation chromatography and of the chemical composition distribution measured by either crystallization analysis fractionation or temperature rising elution fractionation leads to consistent results that indicate the presence of multiple active site types on the catalyst. This shows that these fractionation techniques, when combined with adequate mathematical models, are powerful tools to understand the behavior of Ziegler‐Natta catalysts and structural properties of the produced resins.