Cationic polymerization of isobutylene by complexes of alkylaluminum dichlorides with diisopropyl ether: An activating effect of water. Issue 16 (30th May 2014)

• Record Type: Journal Article
• Authors: Shiman, Dmitriy I.; Vasilenko, Irina V.; Kostjuk, Sergei V.
• Is Part Of: Journal of polymer science. Volume 52:Issue 16(2014:Aug.)
• Page Start: 2386
• Page End: 2393
• Publication Date: 2014-05-30
• Subjects: 547
• DOI: 10.1002/pola.27253
• Languages: English
• ISSNs: 0887-624X

Abstract

<abstract abstract-type="main"> <title>ABSTRACT</title> <p>The RAlCl<sub>2</sub> × O<italic><sup>i</sup></italic>Pr<sub>2</sub>‐co‐initiated (R = <italic><sup>i</sup></italic>Bu or Et) cationic polymerization of isobutylene in the presence of externally added water (0.016–0.1 mM) in nonpolar <italic>n</italic>‐hexane at 10 °C and high monomer concentration ([IB] = 5.8 M) has been investigated. It was shown that the sequence of H<sub>2</sub>O introduction into the system had the crucial effect on the polymerization rate, saturated monomer conversion, and, to a lesser extent, the content of exo‐olefin end groups. Particularly, the highest polymerization rate (>70% of monomer conversion in 10 min) and acceptable exo‐olefin end groups content (∼83%) were observed when <italic><sup>i</sup></italic>BuAlCl<sub>2</sub> × 0.8O<italic><sup>i</sup></italic>Pr<sub>2</sub> reacted with suspended in <italic>n</italic>‐hexane H<sub>2</sub>O before the monomer addition. Better functionality can be obtained when H<sub>2</sub>O is introduced into the system in the course of the polymerization (after 3–10 min since the initiation of reaction). Under these conditions, highly reactive polyisobutylenes (exo‐olefin content is 86–89%) with desired low molecular weight (<italic>M</italic><sub>n</sub> = 1000–2000 g mol<sup>−1</sup>) in a high yield (75–90% of monomer conversion in 20 min) were readily synthesized. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. <bold>2014</bold>, <italic>52</italic>, 2386–2393</p> </abstract>