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A New Insight into the Mechanism of 1,3‐Dienes Cationic Polymerization III: Polymerization of 1,3‐Pentadiene with CF 3 COOD/TiCl 4 Initiating System: Chain‐Ends Structure and Kinetics
Author(s) -
Rozentsvet Victor A.,
Kozlov Valery G.,
Korovielly A.,
Novakov Ivan A.,
Kostjuk Sergei V.
Publication year - 2014
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.201400102
Subject(s) - cationic polymerization , polymerization , monomer , chain transfer , polymer chemistry , chain propagation , chemistry , polymer , living polymerization , chain (unit) , reaction rate constant , chain growth polymerization , solution polymerization , chain termination , kinetics , radical polymerization , organic chemistry , physics , quantum mechanics , astronomy
A novel method for the investigation of the chain‐end structure of poly(1,3‐pentadiene)s synthesized using the CF 3 COOD/TiCl 4 initiating system is developed. It is shown for the first time that the content of trans ‐1,2‐structures in the first monomer unit is considerably higher than the content of trans ‐1,4‐structures, whereas the content of trans ‐1,4‐units is substantially higher than trans ‐1,2‐units for the polymer chain as a whole. Another important observation is that chain transfer to monomer is significant even at the earlier stages of the 1,3‐pentadiene polymerization (after 1 s of reaction). The very low functionality at the ω‐end ( F n (Cl) < 0.15) confirms the intensive chain transfer to monomer. This method is also applied for the estimation of the concentration of active species and the rate constant for propagation ( k p ) for the cationic polymerization of 1,3‐pentadiene using the CF 3 COOD/TiCl 4 initiating system: rate constants for propagation, k p , of 1.5 × 10 3 and 3.3 × 10 3 L mol −1 min −1 are determined for 1,3‐pentadiene polymerization at 20 and –78 °C, respectively.