Premium
Characterization of Intramolecular Composition Heterogeneity of Metallocene‐Based and Conventional Ethylene‐Butene Copolymers using TREF/DSC
Author(s) -
Xu Junting,
Xu Xurong,
Feng Linxian,
Chen Linsen,
Chen Wei
Publication year - 2001
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(20010601)202:9<1524::aid-macp1524>3.0.co;2-#
Subject(s) - metallocene , copolymer , ethylene , polymer chemistry , 1 butene , intramolecular force , materials science , characterization (materials science) , chemistry , chemical engineering , polymerization , organic chemistry , catalysis , polymer , nanotechnology , engineering
A new and convenient method for the qualitative characterization of intramolecular composition heterogeneity was established. The metallocene‐based and conventional ethylene‐butene copolymers were fractionated with preparative temperature rising elution fractionation (TREF) technique, and some selected fractions were directly characterized with differential scanning calorimetry (DSC) after stepwise crystallization. The observed multiple endotherms in the melting traces of some fractions were attributed to intramolecular composition heterogeneity after other possibilities were excluded. It is found that intramolecular composition heterogeneity is present in both metallocene‐based and conventional ethylene‐butene copolymers, but the metallocene‐based copolymers may have a relatively narrower intramolecular composition distribution. Moreover, the mechanism of this method and its applicable range are also discussed.