A New Synthetic Method for the Preparation of Star-Shaped Polyisobutylene with Hyperbranched Polystyrene Core

✍ Scribed by Gergely Kali; Márta Szesztay; Andrea Bodor; Béla Iván

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 195 KB
• Volume: 208
• Category: Article
• ISSN: 1022-1352
• DOI: 10.1002/macp.200700135

✦ Synopsis

Abstract

Friedel–Crafts self‐grafting of polystyrene (PSt) under quasiliving carbocationic polymerization was utilized to develop a new rapid one‐pot method for the preparation of star‐shaped polyisobutylene (PIB). First, the polymerization of isobutylene led to PIB with predetermined molecular weight ($\overline M _{\rm n}$ = 2 000) and narrow molecular weight distribution ($\overline M _{\rm w} /\overline M _{\rm n}$ = 1.03). Then addition of relatively small amount of styrene after isobutylene consumption yielded PIB‐PSt diblocks. Multiple alkylation of the resulting PSt segments by the polystyryl cations led to hyperbranched PSt cores coupling PIB chains to form a star polymer in short reaction time (within an hour) compared to reported methods. The formation of star polymers by this self‐grafting mechanism was proved by gel permeation chromatography equipped with online viscosimeter and ^1^H NMR spectroscopy.

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