A New Insight into the Mechanism of 1, 3‐Dienes Cationic Polymerization I: Polymerization of 1, 3‐Pentadiene with tBuCl/TiCl4 Initiating System: Kinetic and Mechanistic Study. Issue 23 (23rd September 2013)

• Record Type: Journal Article
• Authors: Rozentsvet, Victor A.; Kozlov, Valery G.; Korovina, Nelly A.; Kostjuk, Sergei V.
• Is Part Of: Macromolecular chemistry and physics. Volume 214:Issue 23(2013:Dec.)
• Page Start: 2694
• Page End: 2704
• Publication Date: 2013-09-23
• Subjects: Polymers -- Periodicals; Polymerization -- Periodicals; Synthetic products -- Periodicals; Macromolecules -- Periodicals; 547.7
• DOI: 10.1002/macp.201300470
• Languages: English
• ISSNs: 1022-1352

Abstract

<abstract abstract-type="main" xml:lang="en"> <title> <x xml:space="preserve">Abstract</x> </title> <p>The cationic polymerization of 1, 3‐pentadiene using a <italic>tert</italic>‐butyl chloride (<italic><sup>t</sup></italic>BuCl)/TiCl<sub>4</sub> initiating system in CH<sub>2</sub>Cl<sub>2</sub> at different reaction conditions is reported. It is shown that the reaction rate increases with the increase of the <italic><sup>t</sup></italic>BuCl/TiCl<sub>4</sub> molar ratio, while the molecular weight distribution becomes narrower. Well‐defined oligo(1, 3‐pentadiene)s (<alternatives><inline-graphic mimetype="image" xlink:href="ark:/27927/pgg3z8rt0cg" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /><mml:math display="inline" altimg="urn:x-wiley:10221352:macp201300470:equation:macp201300470-math-0001" overflow="scroll" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mover accent="true"><mml:mi>M</mml:mi><mml:mo>¯</mml:mo></mml:mover><mml:mi mathvariant="normal">n</mml:mi></mml:msub></mml:math></alternatives> ≤ 3500 g mol<sup>−1</sup>; <alternatives><inline-graphic mimetype="image" xlink:href="ark:/27927/pgg3z8rt0bx" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /><mml:math display="inline" altimg="urn:x-wiley:10221352:macp201300470:equation:macp201300470-math-0002" overflow="scroll" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mover accent="true"><mml:mi>M</mml:mi><mml:mo>¯</mml:mo></mml:mover><mml:mi mathvariant="normal">w</mml:mi></mml:msub></mml:math></alternatives>/<alternatives><inline-graphic mimetype="image" xlink:href="ark:/27927/pgg3z8rt09c" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /><mml:math display="inline" altimg="urn:x-wiley:10221352:macp201300470:equation:macp201300470-math-0003" overflow="scroll" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mover accent="true"><mml:mi>M</mml:mi><mml:mo>¯</mml:mo></mml:mover><mml:mi mathvariant="normal">n</mml:mi></mml:msub></mml:math></alternatives> ≤ 3.0) are obtained at high <italic><sup>t</sup></italic>BuCl/TiCl<sub>4</sub> molar ratio (340) and low temperature (–78 °C). <sup>1</sup>H and <sup>13</sup>C NMR spectroscopy studies reveal the presence of <italic>tert</italic>‐butyl head and –CH<sub>2</sub>–Cl end groups. The number‐average functionalities (<italic>F</italic><sub>n</sub>s) at the α‐ and ω‐ends are calculated to be <italic>F</italic><sub>n</sub>(<italic><sup>t</sup></italic>Bu) > 1 and <italic>F</italic><sub>n</sub>(Cl) < 1, respectively. The general mechanism of 1, 3‐pentadiene polymerization is proposed. <boxed-text content-type="graphic" position="anchor" orientation="portrait"><graphic position="anchor" mimetype="image" xlink:href="ark:/27927/pgg3z8rt3c1" orientation="portrait" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /></boxed-text></p> </abstract>