Abstract: The invention describes hydrophilically acting shaped objects, in particular semipermeable membranes for pyrogen retention, comprising a synthetic polymer component and an additive made from a copolymer made from vinylpyrrolidone and a vinylimidazole compound, and furthermore processes for manufacturing the shaped objects. The shaped objects of the invention exhibit such a high pyrogen retention capacity that the pyrogen concentrations present in the filtrates are in part below the detection limit of the gel clot LAL test.

Abstract: Process for producing integrally asymmetrical hydrophobic polyolefinic membranes with a separation layer, in particular for gas exchange, via thermally induced liquid-liquid phase separation. A solution of at least one polyolefin in a solvent system containing a compound A and a compound B is extruded to form a shaped object. Compound A is a strong solvent and compound B a weak non-solvent for the polymer. After leaving the die, the shaped object is cooled using a solid or liquid cooling medium, which does not dissolve the polymer and does not react chemically with it, until the phase separation and solidification of the high-polymer-content phase take place.

Abstract: Block copolymers containing blocks of unsulfonated aromatic polyether sulfones and blocks of aromatic polyether sulfones sulfonated on the aromatics are characterized in that the block length of the unsulfonated aromatic polyether sulfones in each case comprises at least 10 repeating units and that the sequence of the main chain at the block transitions between two adjacent blocks of aromatic polyether sulfones is the same as it is inside these blocks. These block copolymers may be prepared by polycondensation, and are preferably used as membranes. The block copolymers provide compounds which in addition to an adjustable degree of sulfonation have a defined length of sulfonated and unsulfonated blocks. As a result, the spectrum of the polymers suitable for the preparation of synthetic membranes can be expanded and graded.

Abstract: Process for producing hydrophobic polyolefinic membranes for gas exchange via thermally induced liquid-liquid phase separation is disclosed. A solution of at least one polyolefin in a solvent system, of a compound A and a compound B having a viscosity less than 60 mPa s, is extruded to form a shaped object. The compound A is a solvent and compound B preferably a non-solvent of the polymer, and the boiling point of compound A is at least 50° C. higher than that of compound B. After the shaped object leaves the die, at least one surface thereof is subjected to an atmosphere promoting evaporation of compound B, and the shaped object is subsequently cooled until the phase separation and solidification of the high-polymer-content phase take place.

Abstract: 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.

Abstract: Process for producing an integrally asymmetrical hydrophobic polyolefinic membrane with a sponge-like, open-pored, microporous support structure and a separation layer with a denser structure compared to the support structure, via a thermally induced liquid-liquid phase separation process. A solution of at least one polyolefin in a solvent system consisting of a compound A and a compound B is extruded to form a shaped object. Compound A is a weak solvent and compound B a non-solvent for the polymer. After leaving the die, the shaped object is cooled using a solid or liquid cooling medium that does not dissolve or react chemically with the polymer at temperatures up to the die temperature, until the phase separation and solidification of the high-polymer-content phase take place.

Abstract: The invention describes hydrophilically acting shaped objects, in particular semipermeable membranes for pyrogen retention, comprising a synthetic polymer component and an additive made from a copolymer made from vinylpyrrolidone and a vinylimidazole compound, and furthermore processes for manufacturing the shaped objects. The shaped objects of the invention exhibit such a high pyrogen retention capacity that the pyrogen concentrations present in the filtrates are in part below the detection limit of the gel clot LAL test.