Preparation of polytetrahydrofuran with terminal hydroxyl groups using ion exchangers

US6037381A · kind A · utility

Assignee

• BASF SE

Inventors

• Wulfrich Friedemann Beer · Neustadt, DE
• Klaus Beiser · Eppelsheim, DE
• Jurgen Ciprian · Ludwigshafen, DE
• Lothar Franz · Ludwigshafen, DE
• Wolfgang Franzischka · Bischofswerda, DE
• Christof Palm · Ludwigshafen, DE
• Frank-Friedrich Pape · Kleinniedesheim, DE
• Axel Paul · Lampertheim, DE
• Ulrich-Dieter Pessel · Heidelberg, DE
• Alexander Weck · Freinsheim, DE

Key dates

• Filing date: Dec 28, 1998
• Grant date: Mar 14, 2000
• Expiry date: Dec 28, 2018

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G65/20
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

The invention relates to a process for preparing hydroxyl-containing polymers, in particular for preparing polytetrahydrofuran with terminal hydroxyl groups, from the corresponding acyloxy-containing polymers by transesterification with alcohols in the presence of a sodium-containing catalyst. In this process the polytetrahydrofuiran solution is passed in the presence of a catalytic amount of water directly through at least one ion exchanger following the transesterification in order to remove the sodium cations. The novel process makes it possible to remove the sodium cations from the sodium-containing catalyst in an economic manner and with little complexity. The residual sodium content can be reduced to values of less than 0.5 ppm.