Bayer Aktiengesellschaft

Wolfgang Arlt

Manfred Schmidt

Erhard Tresper

Thomas Fischer

Andreas Nickel

Dieter Arlt

Alexander Klausener

Paul Wagner

Claus H Wulff

Wolfgang Alewelt

Helmut Waniczek

Wolfgang Jakob

Karl-Heinrich Meyer

Wolfgang Russeler

Wolfgang Wehnert

Gabriel Denecker

Ralf Lange

Wolfgang M Eisermann

Hans-Walter Brandt

Dieter W Bruck

Hanns-Ingolf Paul

Ingo Janisch

Ulrich Schwartz

Karl-Dieter Lohr

Hans-Joachim Traechkner

Richard Viard

A first alkanol having 1 to 3 C atoms or a mixture of this first alkanol with water or water itself can be separated off from oxygen-containing organic compounds having 3 to 7 C atoms from the group comprising second alkanols and dialkyl carbonates, which always have at least 2 C atoms more than the first alkanol, by permeation on membranes if a membrane obtained by plasma polymerization is employed.

Process for separating off alkanols, mixtures of alkanols and water or

A process for cleaning thermoplasts is described. The thermoplast to be cleaned is introduced between the discs of a plast compactor and substantially freed from unwanted residues from the polymerization process by the force and rise in temperature produced by the movement of rotation.

Process for cleaning thermoplasts by friction compacting

This invention relates to a simplified process for the preparation of polyarylene sulphides with improved product quality from alkali metal sulphides and dihalogenated aromatic compounds, in which the alkali metal sulphides are prepared and reacted in situ.

Process for the preparation of polyarylene sulphides

The invention relates to a process for stabilizing the molecular weight of high molecular weight, optionally branched polyarylene sulfides prepared by reaction of aromatic dihalogen compounds and, optionally, aromatic trihalogen or tetrahalogen compounds and, optionally, polymer-chain-terminating monomers with alkali metal sulfides and/or alkali metal hydrogen sulfides at elevated temperature in aprotic polar solvents, characterized in that, after the desired molecular weight has been reached, alkali metal sulfides and/or alkali metal hydrogen sulfides present in excess are at least partly reacted with acids to form the alkali metal salts of the acids and hydrogen sulfide.

Process for stabilizing the molecular weight of linear or optionally

This invention relates to a process for the isolation and purification of polyarylene sulphides, preferably polyphenylene sulphides, from their reaction mixture. The process requires no organic solvents for the purification (washing) of the polymer.

Process for the isolation and purification of polyarylene sulphides

This invention relates to a process for the production of high molecular weight, optionally branched polyarylene sulfides having a reduced content of extractable oligomeric constituents. They are prepared by reaction of alkali sulfides and/or alkali hydrogen sulfides with aromatic dihalogen compounds in a polar organic solvent.

Process for the production of high molecular weight, optionally branched

By treating aromatic polycarbonates, aromatic polyester carbonates and aromatic and/or araliphatic polyesters in the molten state with super-critical gases or gas mixtures under pressure, the melt viscosity of these polymers is considerably lowered so that basic chemical operations which proceed only incompletely under the usual conditions can be carried out on these thermoplasts.

Process for lowering the melt viscosity of aromatic polycarbonates,

A process for the production of monomeric .alpha.-cyanoacrylates by pryrolysis of poly-.alpha.-cyanoacrylates and subsequent distillation of the resulting monomeric .alpha.-cyanoacrylates.

Process for the production of monomeric .alpha.-cyanoacrylates

Diastereomers can be separated with good industrial success with the aid of extractive distillation. The separation process is characterized in that an auxiliary which changes the partial pressure of the various diastereomers to be separated to a different degree and thus allows easier separation of the diastereomers by distillation is added during the distillation. Using the present process diastereomic cis/trans-permetric acid methyl esters and mixtures of menthol and isomenthol can be separated with isolation of 99% pure product.

Separation of diastereomers by extractive distillation

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Krefeld, Germany

Wolfgang Arlt