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Heterogeneous anionic coordinated polymerization of propylene oxide: A quantitative 13 c NMR analysis of the regio‐ and stereo‐selectivity of the catalyst via microstructure analysis of polymers
Author(s) -
Goriot R.,
Pétiaud R.,
Llauro M. F.,
Hamaide T.
Publication year - 1997
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.19971190118
Subject(s) - diad , tacticity , triad (sociology) , propylene oxide , selectivity , polymer , catalysis , materials science , oxide , polymerization , polymer chemistry , analytical chemistry (journal) , chemistry , organic chemistry , copolymer , composite material , metallurgy , psychology , ethylene oxide , psychoanalysis
Poly(propylene oxide)s synthesized with an heterogeneous catalytic system have been analyzed by 13 C NMR spectroscopy by using DEPT experiments and sub‐spectrum editing techniques. The results have been compared with those obtained from commercial products, in order to reach a greater insight into the selectivity of the catalytic system. A quantitative and reliable determination of the inversion ratio is proposed, which implies each type of carbon as well. This inversion ratio was found to be much higher than that observed in commercial PPO. It is shown that when the inversion ratio is no longer negligeable, its accurate determination is a prerequisite to a reliable approach of the tacticity distribution in regular sequences. So, a quantitative determination of the configurational diad and triad distribution is proposed which takes into account the fraction of “defect” resonances (consequence of inverted addition) overlapping with “normal” resonances (unaffected by the inverted addition) in the different sub‐spectra. The main features of the catalyst activity are outlined and compared with results obtained with commercial PPO.