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Advances in the 13 C NMR characterization of ethene/propene copolymers, 1
Author(s) -
Busico Vincenzo,
Cipullo Roberta,
Segre Anna Laura
Publication year - 2002
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(200207)203:10/11<1403::aid-macp1403>3.0.co;2-i
Subject(s) - copolymer , triad (sociology) , metallocene , propene , carbon 13 nmr , polymer chemistry , tacticity , materials science , nmr spectra database , proton nmr , chemistry , sequence (biology) , catalysis , spectral line , polymerization , organic chemistry , physics , polymer , psychology , biochemistry , astronomy , psychoanalysis
The microstructure of a number of ethene/propene copolymers prepared with three representative C 2 ‐symmetric ansa ‐metallocene catalysts was investigated by means of high‐field (150 MHz) 13 C NMR. Thanks to the exceedingly high resolution of the spectra, an unprecedented experimental basis for the constitutional sequence analysis was achieved, which enabled us to test complex statistical models of chain propagation in a significant manner. In particular, the need for a 2 nd ‐order Markov model, previously suggested by some authors on the basis of triad data, was confirmed by our study at pentad/heptad level. Some correlations between metallocene structure and copolymerization statistics were also identified.Expansion of the methyl region of the 13 C NMR spectrum of an E/P copolymer obtained at 30 °C with catalyst system I/MAO (150 MHz).