Patent ID: 6362312
Filing Date: 2002-03-26
Classification: C08G

Abstract:
A process for preparing polytetrahydrofuran, polytetrahydrofuran copolymers or diesters or monoesters thereof, which comprises polymerizing tetrahydrofuran in the presence of at least one telogen and/or comonomer over an acid-activated calcium montmorillonite as catalyst having a BET surface area of at least 300 m2/g, an acidity of at least 0.02 mmol/g at pKa3/g for pore sizes in the range from 30 to 200 Ã¥, And wherein the telogen and/or comonomer is water, 1,4-butanediol, 2-butyne-1,4-diol,polytetrahydrofuran having a molecular weight of from 200 to 700 dalton, a C1-C20-monocarboxylic acid, a C2-C20monocarboxylic anhydride, a 1,2-alkylene oxide, 2-methyltetrahydrofuran, 3- -methytetrahydrofuran, a diol or a mixture thereof.