A New Insight into the Mechanism of 1, 3‐Dienes Cationic Polymerization III: Polymerization of 1, 3‐Pentadiene with CF3COOD/TiCl4 Initiating System: Chain‐Ends Structure and Kinetics. Issue 12 (21st May 2014)

• Record Type: Journal Article
• Authors: Rozentsvet, Victor A.; Kozlov, Valery G.; Korovina, Nelly A.; Novakov, Ivan A.; Kostjuk, Sergei V.
• Is Part Of: Macromolecular chemistry and physics. Volume 215:Issue 12(2014:Jun.)
• Page Start: 1239
• Page End: 1249
• Publication Date: 2014-05-21
• Subjects: Polymers -- Periodicals; Polymerization -- Periodicals; Synthetic products -- Periodicals; Macromolecules -- Periodicals; 547.7
• DOI: 10.1002/macp.201400102
• Languages: English
• ISSNs: 1022-1352

Abstract

<abstract abstract-type="main" xml:lang="en"> <title> <x xml:space="preserve">Abstract</x> </title> <p>A novel method for the investigation of the chain‐end structure of poly(1, 3‐pentadiene)s synthesized using the CF<sub>3</sub>COOD/TiCl<sub>4</sub> initiating system is developed. It is shown for the first time that the content of <italic>trans</italic>‐1, 2‐structures in the first monomer unit is considerably higher than the content of <italic>trans</italic>‐1, 4‐structures, whereas the content of <italic>trans</italic>‐1, 4‐units is substantially higher than <italic>trans</italic>‐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 (<italic>F<sub>n</sub></italic>(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 (<italic>k</italic><sub>p</sub>) for the cationic polymerization of 1, 3‐pentadiene using the CF<sub>3</sub>COOD/TiCl<sub>4</sub> initiating system: rate constants for propagation, <italic>k</italic><sub>p</sub>, of 1.5 × 10<sup>3</sup> and 3.3 × 10<sup>3</sup> L mol<sup>−1</sup> min<sup>−1</sup> are determined for 1, 3‐pentadiene polymerization at 20 and –78 °C, respectively. <boxed-text content-type="graphic" position="anchor" orientation="portrait"><graphic position="anchor" mimetype="image" xlink:href="ark:/27927/pghmh7tcbb" orientation="portrait" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /></boxed-text></p> </abstract>