摘要:
A process for polymerizing cyclic ethers over a heterogeneous catalyst comprises using a heterogeneous catalyst comprising one or more pillared interlayered clays (PILCs).
摘要:
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.
摘要:
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. after application of the precursor compounds of the oxygen-containing molybdenum and/or tungsten compounds onto the support material precursor, wherein the catalyst is activated by treatment with a reducing agent before it is used as a polymerization catalyst.
摘要:
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.
摘要:
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
摘要:
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.
摘要:
A process for preparing halogen-free, reactive polyisobutene having a terminal double bond content of more than 50 mol % and an average molecular weight Mn of 280-10000 dalton by the cationic polymerization in the liquid phase of isobutene or hydrocarbon mixtures comprising isobutene comprises polymerizing at from −30° C. to +40° C. in the presence of a heterogeneous polymerisation catalyst comprising one or more oxides of the elements of transition groups V and VI of the Periodic Table of the Elements or in the presence of a heterogeneous polymerization catalyst comprising one or more oxidic compounds of one or more elements of transition groups V and VI of the Periodic Table of the Elements supported on a non-zeolitic oxidic support material which is not an oxygen-containing zirconium compound, the catalyst not containing a technically effective amount of halogen.
摘要:
A process for preparing polytetrahydrofuran, polytetrahydrofuran copolymers or diesters or monoesters of these polymers comprises polymerizing tetrahydrofuran in the presence of at least one telogen and/or comonomer over a heterogeneous catalyst comprising hectorite.
摘要:
A process for oxidizing an organic compound having at least one C—C double bond or a mixture of two or more thereof comprises the following steps: (I) preparing a hydroperoxide, (II) reacting an organic compound having at least one C—C double bond or a mixture of two or more thereof with the hydroperoxide prepared in step (I) in the presence of a zeolite catalyst, (III) regenerating the at least partially deactivated zeolite catalyst used in step (II), and (IV) conducting the reaction of step (II) using a zeolite catalyst containing the catalyst regenerated in step (III).
摘要:
In a process for preparing polytetrahydrofuran, polytetrahydrofuran copolymers or diesters or monoesters thereof by polymerization of tetrahydrofuran in the presence of at least one telogen and/or comonomer over acid-activated montmorillonite catalysts, the montmorillonite catalyst after acid activation has a ratio of montmorillonite structure to the sum of muscovite and kaolin structures, determined from the intensities of the reflections at 2&thgr;=5.5° for montmorillonite, 2&thgr;=9.0° for muscovite and 2&thgr;=12.5° for kaolin measured in the X-ray powder pattern, of at least 5:1.