Evonik Stockhausen Gmbh

Evonik Degussa Gmbh

Jörg Leistner

Franz-Felix Kuppinger

Jürgen Mosler

Guido Stochniol

Markus Winterberg

Franck Furno

Günther Bub

Andreas Sabbagh

Udo Knippenberg

Jörg Sauer

Günter Latoschinski

Thorsten Schwärtzke

Axel Hengstermann

Arndt Selbach

Jürgen Kohn

Peter Jansens

Ludwig Papajewski

Hans-Günter Sparenberg

The present invention relates to a method for purifying an unpurified phase, containing a target product, preferably (meth)acrylic acid, water, and at least one impurity differing from the target product and from water comprising: a) crystallizing the target product and water; b) separating the crystals from the mother liquor created in step a); c) melting at least part of the separated crystals to form a melt; and d) recycling at least part of said melt to step b). The invention further relates to a method for the production of a purified phase, containing a target product and water, a method for the production of a polymer based on (meth)acrylic acid, polymers that may be obtained by means of said method, chemical products, such as fibers or molded bodies, and the use of polymers.

Method for producing and purifying aqueous phases

The present invention relates to superabsorbent polymer comprising acrylic acid made by the process comprising the steps of heating an aqueous glycerine solution to form glycerine; transporting the glycerine to the dehydration reactor; dehydrating the glycerine to an acrolein-comprising dehydration product; gas phase oxidating of the acrolein-comprising dehydration product to obtain an acrylic acid-comprising monomer gas; bringing into contact of the monomer gas with a quench agent to obtain an acrylic acid-comprising quench phase; working-up the quench phase to obtain an acrylic acid-comprising monomer phase; and polymerizing the acrylic acid-comprising monomer phase; wherein a plurality of gas bubbles is generated and wherein the dehydration occurs at least partially in the liquid phase. The superabsorbent polymer has certain properties for biodegradability and sustainability. Further, at least about 25% of the acrylic acid is based on glycerine. The superabsorbent polymer has a sustainability factor of at least about 80%.

Water-absorbing polymer structures based on renewable raw materials and process for their production by dehydration

The present invention relates to a process for production of acrylic acid, comprising the steps of a) dehydration of glycerine to an acrolein-comprising dehydration product; b) gas phase oxidation of the dehydration product to obtain an acrylic acid-comprising monomer gas; c) bringing into contact of the monomer gas with a quench agent to obtain an acrylic acid-comprising quench phase; and d) work-up of the quench phase to obtain an acrylic acid-comprising monomer phase; whereby, during the dehydration a liquid phase a1 and a gas phase a2 is present, whereby in the liquid phase a1 a plurality of gas bubbles is generated, as well as a process for production of polymers by polymerization of acrylic acid, preferably for production of water-absorbing polymers, the water-absorbing polymers obtainable by this process, a composite, a process for production of a composite, the composite obtainable by this process, and further chemical products.

Acrylic acid and water-absorbing polymer structures based on renewable raw materials and process for their production by dehydration

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Rheda-Wiedenbrück, Germany

Jörg Leistner