Method for the single-step production of polytetrahydrofuran and tetrahydrofuran copolymers

US6716937B2 · kind B2 · utility

Assignee

• BASF SE

Inventors

• Gerd Bohner · Malsch, DE
• Thomas Domschke · Speyer, DE
• Rolf Fischer · Heidelberg, DE
• Martin Haubner · Ludwigshafen am Rhein, DE
• Christoph Sigwart · Schriesheim, DE
• Ulrich Steinbrenner · Kohlhof, DE
• Christian Tragut · Monsheim, DE

Key dates

• Filing date: Jan 2, 2003
• Grant date: Apr 6, 2004
• Expiry date: Jan 2, 2023

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G65/20
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

A process for the single-stage preparation of polytetrahydrofuran and/or tetrahydrofuran copolymers having a mean molecular weight of from 650 to 5000 dalton by polymerization of tetrahydrofuran over a heterogeneous acid catalyst in the presence of at least one telogen and/or comonomer selected from the group consisting of alpha,omega-diols, water, polytetrahydrofuran having a molecular weight of from 200 to 700 dalton and cyclic ethers comprisesa) separating off the catalyst and/or downstream products of the catalyst suspended and/or dissolved in the output from the polymerization,b) fractionating the resulting catalyst-free output from the polymerization in at least one distillation step to give a distillation residue comprising the polymerization product and at least one tetrahydrofuran fraction and returning at least part of the tetrahydrofuran fraction to the polymerization andc) separating low molecular weight polytetrahydrofuran and/or tetrahydrofuran copolymers having a mean molecular weight of from 200 to 700 dalton from the distillation residue from work-up step b) and isolating polytetrahydrofuran and/or tetrahydrofuran copolymers having a mean molecular weight of from 6…