Abstract: A process for polymerizing cyclic ethers over a heterogeneous catalyst comprises using a heterogeneous catalyst comprising one or more pillared interlayered clays (PILCs).

Abstract: Polytetrahydrofuran, tetrahydrofuran copolymers, diesters or monoesters of these polymers are prepared by polymerizing tetrahydrofuran in the presence of at least one telogen and/or comonomer on a heterogeneous carrier catalyst which contains on an oxidic carrier material as active mass a catalytically active amount of at least one oxygenous molybdenum and/or tungsten compound and, when the precursor compounds of the active mass have been applied to the carrier material precursor, has been calcined at temperatures of between 500° C. and 1000° C. The catalyst used contains a promotor which comprises at least one element or a compound of an element of the 2nd, 3rd including the lanthanides, 5th, 6th, 7th, 8th or 14th group of the periodic system of elements.

Abstract: The invention relates to a method for producing polytetrahydrofuran, polytetrahydrofuran copolymers, diesters or monoesters of these polymers by polymerization of tetrahydrofuran in the presence of at least one telogene and/or comonomer on a sulfate-containing heterogeneous supported catalyst. A sulfate-containing heterogeneous supported catalyst is used containing at least one metal sulfate, metal hydrogen sulfate, metal oxide sulfate or mixtures thereof.

Abstract: Polytetrahydrofuran, copolymers of tetrahydrofuran and 2-butyne-1,4-diol, diesters of these polymers with C.sub.2 -C.sub.20 -monocarboxylic acids or monoesters of these polymers with C.sub.1 -C.sub.10 -monocarboxylic acids are prepared by polymerization of tetrahydrofuran in the presence of one of the telogens water, 1,4-butanediol, 2-butyne-1,4-diol, polytetrahydrofuran having a molecular weight of from 200 to 700 Dalton, a C.sub.1 -C.sub.10 -monocarboxylic acid or an anhydride of a C.sub.2 -C.sub.20 -monocarboxylic acid or a mixture of these telogens over a heterogeneous supported catalyst which comprises a catalytically active amount of an oxygen-containing molybdenum and/or tungsten compound on an oxidic support material and which has been calcined at from 5OO.degree. C. to 1OOO.degree. C.

Abstract: In a process for the preparation of copolymers of tetrahydrofuran and but-2-yne-1,4-diol by catalytic polymerization of tetrahydrofuran, the polymerization is carried out over a heterogeneous acidic catalyst which has acid centers of acidity pK.sub.a <+2 in a concentration of at least 0.005 mmol/g of catalyst, in the presence of but-2-yne-1,4-diol. In particular, for the preparation of polyoxytetramethylene glycol, the copolymers are reacted in the presence of hydrogen over a hydrogenation catalyst.

Abstract: Tetrahydrofuran/but-2-yne-1,4-diol copolymers containing C--C triple bonds and having an average molecular weight M.sub.n of from 500 to 3500 Dalton and a content of from 0.5 to 3 mol of triple bonds/mol of copolymer and blends of these copolymers with polytetrahydrofuran having an average molecular weight M.sub.n of from 500 to 3500 Dalton, processes for their preparation and their use.

Abstract: A process for the preparation of polytetrahydrofuran or polytetrahydrofuran monoesters of C.sub.1 -C.sub.10 monocarboxylic acids by the polymerization of tetrahydrofuran over a heterogeneous catalyst in the presence of one of the telogens water, 1,4-butanediol or polytetrahydrofuran having a molecular weight of from 200 to 700 dalton or a C.sub.1 -C.sub.10 monocarboxylic acid or mixtures of these telogens, wherein a supported catalyst is used as catalyst, which contains a catalytically active amount of an oxygen-containing tungsten or molybdenum compound or mixtures of these compounds on an oxidic support material and which was calcined at temperatures ranging from 500.degree. to 1000.degree. C. following the application of the precursor compounds of said oxygen-containing molybdenum and/or tungsten compounds to the support material precursor.