Method for producing sulfonated aromatic polymers and use of the process products for producing membranes

US6790931B2 · kind B2 · utility

Assignee

• Celanese Ventures GmbH · DE

Inventors

• Wei Cui · London, GB
• Thomas Soczka-Guth · Schelklingen, DE
• Georg Frank · Nürnberg, DE

Key dates

• Filing date: Jan 13, 2003
• Grant date: Sep 14, 2004
• Expiry date: Jan 13, 2023

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02P70/50
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

A novel non-aggressive sulfonating process for aromatic polymers is described.The process encompasses:a). dissolving the aromatic polymer in a substantially anhydrous acid selected from the group consisting of concentrated sulfuric acid, chlorosulfonic acid, and oleum,b) adding an organic solvent which is inert under the conditions of the reaction,c) adding a carboxylic anhydride,d) adding a sulfonating agent, ande) carrying out the sulfonation at a temperature below 25° C. and for a time sufficient to achieve the desired degree of sulfonation.The resultant homogeneous products of the process may preferably be used to produce membranes, for example for fuel cell applications