Porous air permeable expanded PTFE composite with enhanced mechanical and thermal properties are described. The node and fibril microstructure of expanded PTFE is coated on and within the node and fibril microstructure with a suitably chosen polymer to impart property enhancement while maintaining porosity. The coating polymer content of the composite is maintained between 3 and 25 weight percent of the composite and the areal mass of the composite is less than 75 gm/m.sup.2. Exemplary enhancement to properties may include, among others, Average Tensile Strength (ATS) (in MPa)?Z strength (in MPa) of 50 MPa.sup.2 or greater, preferably 100 MPa.sup.2 or greater, with air flow less than 500 Gurley seconds. Coating polymers with appropriate temperature resistance provides composites which further exhibit shrinkage of less than 10% at temperatures up to 300? C. with air flow of less than 500 Gurley seconds.

An air-impermeable water vapor transport membrane comprises an active layer on a microporous polymeric substrate. The active layer comprises a polyethylene-oxide containing copolymer and a polar protic solvent in an amount of about 3% to about 100% of copolymer weight in the active layer. Molecules of the protic solvent are bonded to the copolymer. The polar protic solvent reduces temperature-dependent variability in the water-vapor permeability of the membrane.

An air-impermeable water vapor transport membrane comprises an active layer on a microporous polymeric substrate. The active layer comprises a polyethylene-oxide containing copolymer and a polar protic solvent in an amount of about 3% to about 100% of copolymer weight in the active layer. Molecules of the protic solvent are bonded to the copolymer. The polar protic solvent reduces temperature-dependent variability in the water-vapor permeability of the membrane.

The present invention is directed to a process for the preparation of a tube with an outer diameter in the range of from 10 m to 250 m consisting of a composition comprising a thermoplastic polyurethane as well as to a tube with an outer diameter in the range of from 10 m to 250 m consisting of a composition comprising a thermoplastic polyurethane obtained or obtainable by the process according to the invention. The invention is further directed to the use of a tube according to the invention as a tube for the transportation of a fluid or as gas membrane tube or as an elastic fiber.

The present invention is directed to a process for the preparation of a tube with an outer diameter in the range of from 10 m to 250 m consisting of a composition comprising a thermoplastic polyurethane as well as to a tube with an outer diameter in the range of from 10 m to 250 m consisting of a composition comprising a thermoplastic polyurethane obtained or obtainable by the process according to the invention. The invention is further directed to the use of a tube according to the invention as a tube for the transportation of a fluid or as gas membrane tube or as an elastic fiber.

The present invention provides a spiral membrane element suitable for suppressing a decrease in a permeation rate of a permeated fluid from a separation membrane. The spiral membrane element of the present invention includes a central tube and a separation membrane that is wound around the central tube. The central tube has an opening for guiding, to an inside of the central tube, a permeated fluid having permeated through the separation membrane. The opening extends in a longitudinal direction of the central tube.

The present invention provides a spiral membrane element suitable for suppressing a decrease in a permeation rate of a permeated fluid from a separation membrane. The spiral membrane element of the present invention includes a central tube and a separation membrane that is wound around the central tube. The central tube has an opening for guiding, to an inside of the central tube, a permeated fluid having permeated through the separation membrane. The opening extends in a longitudinal direction of the central tube.

Polymer composition comprising a) an oligo- or polyurethane U of the formula (I) wherein k and n independently are numbers from 1 to 100, m is from the range 1-100, (X) is a block of formula (II) and (Y) is a block of the formula (III), (A) is a residue of an aliphatic or aromatic diisocyanate linker, (B) is a residue of a linear oligo- or polysiloxane containing alkanol end groups, and optionally further containing one or more aliphatic ether moieties, and (C) is an aromatic oligo- or polyarylene ether block that is at least partly etherified at its terminal positions with one alkylene glycol unit; or a mixture of such oligo- or polyurethanes; and b) one or more further organic polymers P selected from the group consisting of polyvinyl pyrrolidone, polyvinyl acetates, cellulose acetates, polyacrylonitriles, polyamides, polyolefines, polyesters, polyarylene ethers, polysulfones, polyethersulfones, polyphenylenesulfones, polycarbonates, polyether ketones, sulfonated polyether ketones, polyamide sulfones, polyvinylidene fluorides, polyvinylchlorides, polystyrenes and polytetrafluorethylenes, copolymers thereof, and mixtures thereof; preferably selected from the group consisting of polysulfones, polyphenylenes, polyethersulfones, polyvinylidene fluorides, polyamides, cellulose acetate and mixtures thereof.

##STR00001##

Polymer composition comprising a) an oligo- or polyurethane U of the formula (I) wherein k and n independently are numbers from 1 to 100, m is from the range 1-100, (X) is a block of formula (II) and (Y) is a block of the formula (III), (A) is a residue of an aliphatic or aromatic diisocyanate linker, (B) is a residue of a linear oligo- or polysiloxane containing alkanol end groups, and optionally further containing one or more aliphatic ether moieties, and (C) is an aromatic oligo- or polyarylene ether block that is at least partly etherified at its terminal positions with one alkylene glycol unit; or a mixture of such oligo- or polyurethanes; and b) one or more further organic polymers P selected from the group consisting of polyvinyl pyrrolidone, polyvinyl acetates, cellulose acetates, polyacrylonitriles, polyamides, polyolefines, polyesters, polyarylene ethers, polysulfones, polyethersulfones, polyphenylenesulfones, polycarbonates, polyether ketones, sulfonated polyether ketones, polyamide sulfones, polyvinylidene fluorides, polyvinylchlorides, polystyrenes and polytetrafluorethylenes, copolymers thereof, and mixtures thereof; preferably selected from the group consisting of polysulfones, polyphenylenes, polyethersulfones, polyvinylidene fluorides, polyamides, cellulose acetate and mixtures thereof.

##STR00001##

A method for preparing an ionically-charged membrane comprising the steps (1) applying a film of curable composition to a support; (2) curing the film of curable composition to give anionically-charged membrane; and (3) removing the ionically-charged membrane from the support; wherein the curable composition comprises a) 5 to 50 wt % of curable compound comprising one ethylenically unsaturated group and anionic group; b) 10 to 70 wt % of crosslinking agent comprising at least two ethylenically unsaturated groups and having a molecular weight of at least 500 dalton per ethylenically unsaturated group; and c) 5 to 60 wt % of inert solvent.