Gkss-forschungszentrum Geesthacht Gmbh

Membrana Gmbh

Dieter Paul

Bernd Seibig

Wolfgang Albrecht

Quan Huang

Thomas Weigel

Roland Hilke

Klaus-Viktor Peinemann

Mathias Ulbricht

Frank Wiese

Karola Lützow

Gunter Malsch

Barbara Seifert

Rebecca Klotzer

Hans-Georg Hicke

Thomas Groth

Hartmut Stenzel

Lars-Ingemar Dahms

Margot Becker

Ingeburg Lehmann

In a method of manufacturing a double-layer membrane of different polymers or polymer mixtures with opposite blood-compatible and tissue-compatible surfaces, a first polymer solution of a blood-compatible polymer and a second solution of a tissue-compatible polymer are extruded concurrently in layered form through a nozzle into a coagulation bath so as to form a double layer membrane.

Double-layer hollow membrane for bio-reactor applications

Method for producing foamed microporous polymer molded bodies by melting a thermoplastic polymer in a first zone of an extrusion device, mixing in a highly volatile blowing agent, conveying the polymer melt containing the blowing agent into a second zone in which dissolution of the blowing agent occurs to saturation of the polymer melt at the foaming temperature, and molding and foaming of the loaded polymer melt to a foamed structure, whereby, in the second zone, a pressure above 90 bar, a blowing agent concentration above the critical minimum concentration for complete foaming, and the foaming temperature, lying above the solidification temperature of the polymer melt saturated with blowing agent, are set such that the polymer molded body obtained has a porosity in the range between 40 and 90 vol. % and an open-cell pore structure with uniform cross-sectional distribution. Foamed microporous polymer molded bodies in the form of particles comprising a thermoplastic polymer with uniform open-cell pore structure, a porosity of 40 to 90 vol. %, an accessible proportion of pore volume of at least 0.75 and an average cell size between 1 and 100 &#x3bc;m.

Method for producing foamed polymer molded bodies and said foamed polymer molder bodies

In a polyimide molded body, in particular a polyimide membrane which is functionalized with a chemical group and a method for production thereof, a molded body or membrane is obtained, whereby a pre-prepared polyimide body, as starting material, is brought into contact with an aqueous modifier solution for a period of 1 second to 1 hour. The modifier solution contains at least one modifier substance at least partially dissolved therein, which comprises a primary or secondary amino group, or a similar amino group and additionally at least one further functional group per molecule. The polyimide molded body is brought to an elevated temperature, either during the contact period with the modifier solution or thereafter and then purified and dried. The membrane obtained according to the invention may be functionalized in a targeted adjustable manner and has a high functionalization degree. The functionalization may be achieved simply and economically in an aqueous medium. The membranes obtained are suitable for use in the technical, biotechnological and medical fields and as starter membranes for the production of affinity membranes.

Functionalized polyimide molded body and functionalized polyimide membrane

A method using a two part process line is proposed for manufacturing foams from polymers or polymer mixtures useful for making molded bodies. The process line is divided into at least one first part and one second part. The polymer or polymer mixture is melted in the first part and a gas at a pressure increased relative to the melt pressure is added with the influence of a shearing and/or kneading device on the melted polymer or polymer mixture enriched with gas. In the second part of the process line, foam is formed from the gas-enriched polymer or polymer mixture at a higher pressure than the pressure in the first part of the process line. Membranes can be made from the molded bodies made by the method described above.

Method for producing foams made of polymers or polymer mixtures and moulded articles made from said foams

In a method of making solvent and acid resistant membrane on the basis of polyacrylnitrile (PAN) and a comonomer copolymerized therewith wherein the membrane is formed from a solution by phase inversion, glycidylmethacrylate is used as the comonomer and the membrane formed thereby is then subjected to ammonia.

Solvent and acid resistant membrane on the basis of polyacrylnitrile

In a method of producing hollow fiber membranes, wherein a molten polymer charged with a gas under pressure is provided in an extrusion apparatus, the polymer melt including the gas under pressure is extruded from the extrusion apparatus through a hollow fiber-forming extrusion nozzle with a predetermined pressure drop which provides for a concurrent expansion of the gas contained in the polymer melt thereby forming a porous hollow fiber membrane.

Method of producing hollow fiber polymer membranes

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Kleinmachnow, Germany

Dieter Paul