Process for the preparation of tetrahydrofuran polymers

US5886138A · kind A · utility

Inventor

• Herbert Muller · Bischofswerda, DE

Key dates

• Filing date: Jul 30, 1997
• Grant date: Mar 23, 1999
• Expiry date: Jul 30, 2017

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G65/2657
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

A process for the continuous and discontinuous production of tetrahydrofuran polymers by homopolymerizing tetrahydrofuran or copolymerizing tetrahydrofuran with 1,2-alkylene oxides in the presence of compounds with reactive hydrogen or carboxylic acid anhydrides on an acid-treated, calcined and granulated aluminium silicate catalyst which may consist of amorphous aluminium silicate, a zeolite or kaolin. By keeping the concentration of carboxylic acid anhydride or alkylene oxide constant below 1 wt. % in the polymerization recipe throughout the polymerization it is possible to largely prevent the formation of cyclic ethers and to obtain a polymer with a very narrow molecular weight distribution. In granular form, the catalysts exhibit a hitherto unknown activity and form polymers with a very narrow molecular weight distribution and low color and acid numbers.