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A New Insight into the Mechanism of 1,3‐Dienes Cationic Polymerization I: Polymerization of 1,3‐Pentadiene with t BuCl/TiCl 4 Initiating System: Kinetic and Mechanistic Study
Author(s) -
Rozentsvet Victor A.,
Kozlov Valery G.,
Korovielly A.,
Kostjuk Sergei V.
Publication year - 2013
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/macp.201300470
Subject(s) - cationic polymerization , polymerization , chemistry , molar ratio , polymer chemistry , molar mass distribution , solution polymerization , reaction mechanism , polymer , organic chemistry , catalysis
The cationic polymerization of 1,3‐pentadiene using a tert ‐butyl chloride ( t BuCl)/TiCl 4 initiating system in CH 2 Cl 2 at different reaction conditions is reported. It is shown that the reaction rate increases with the increase of the t BuCl/TiCl 4 molar ratio, while the molecular weight distribution becomes narrower. Well‐defined oligo(1,3‐pentadiene)s ( M ¯ n ≤ 3500 g mol −1 ;M ¯ w / M ¯ n ≤ 3.0) are obtained at high t BuCl/TiCl 4 molar ratio (340) and low temperature (–78 °C). 1 H and 13 C NMR spectroscopy studies reveal the presence of tert ‐butyl head and –CH 2 –Cl end groups. The number‐average functionalities ( F n s) at the α‐ and ω‐ends are calculated to be F n ( t Bu) > 1 and F n (Cl) < 1, respectively. The general mechanism of 1,3‐pentadiene polymerization is proposed.