Hoechst Celanese Corporation

Cytec Technology Corporation

Basf Structural Materials, Inc.

Celanese Gmbh

Tai-Shung Chung

Edward R Kafchinski

Paul E McMahon

Gordon W Calundann

Lincoln Ying

Rachel S Kohn

Rohitkumar H Vora

Paul N Chen, Sr

Edward C Chenevey

Herman L LaNieve, Iii

Daniel Palangio

Brenda A Bembry-Ross

Larry F Charbonneau

Balaram B Gupta

Mark A Spak

Paul Foley

Frank J Onorato

Vincent J Provino

Dieter Kurschus

James J Lowery

Michael Haubs

Sunil K Garg

Frank Haimbach, Iv

Richard D Orwoll

Paul J Harget

Arthur G Schlask

Howard Furst

Zev Gurion

Maria R Coleman

Hubert Bader

William Timmons

Jeanne Gasman

E Ronald Kafchinski

C Glen Wensley

Friedrich Herold

The instant invention involves a process used in preparing fibrous tows which may be formed into polymeric plastic composites. The process involves the steps of (a) forming a carbon fiber tow; (b) forming a thermoplastic polymeric fiber tow; (c) intermixing the two tows; and (d) withdrawing the intermixed tow for further use.

Composite fiber blends

Continuous, linearly intermixed fiber tows and composite molded article

A polypropylene or polyethylene film or fiber coated with a maleic-acid grafted polypropylene or polyethylene copolymer layer over which is coated a layer of selective polymer. The copolymer securely bonds the selective polymer to the film or fiber. These fibers and films can be used in fluid separation membranes.

Coated polypropylene or polyethylene useful for membranes

PVP-coated asymmetric hollow fibers made from SIXEFT.TM.-Durene, a polyimide made from 2,2-bis[3,4-dicarboxyphenyl] hexafluoropropane dianhydride and 2,3,5,6-tetramethylphenylene diamine monomers, and a process for making such fibers. These coated fibers have a separation factor that exceeds 6 for oxygen and nitrogen and a permeance of at least about 10 ppm cc(STP)/(sec cm.sup.2 cm-Hg). A polymer dope comprising SIXEF.TM.-Durene in a solvent system containing N-methyl-2-pyrrolidone ('NMP') and an organic acid such as propionic acid ('PA') is prepared by polymerizing the polyimide monomers in NMP to form a polyamic acid polymer and imidizing this polymer using the acid anhydride. Water released from the polymer in the imidization reaction converts the anhydride to acid. The dope is wet-spun into hollow fibers; the fibers are coagulated in water. The fibers are then evenly coated with PVP, preferably by dipping the fibers in a dilute PVP solution.

High selectivity hollow fibers

Asymmetric fluoropolymer hollow fibers having a thin, dense, inner separation layer that is essentially defect-free. In the process of this invention, a fluoropolymer dope is spun into a hollow fiber using a hollow fiber die, a core solvent, preferably comprising water, and a coagulation bath, preferably comprising a water-acetone mixture. Due to solubility and surface tension differences, the outer layer of the fiber does not coagulate quickly enough to form a dense layer, and remains porous, but the core solvent causes the inner surface of the hollow fiber to coagulate into a thin, dense, defect-free layer.

Fabrication of a fluoropolymer hollow fiber having a defect-free

Asymmetric hollow fibers of SIXEF.TM.-Durene, a polyimide made from 2,2-bis[3,4-dicarboxyphenyl] hexafluoropropane dianhydride and 2,3,5,6-tetramethylphenylene diamine monomers, and a process for making such fibers. These uncoated fibers have a separation factor that exceeds 4 for oxygen and nitrogen and a permeance of at least about 50 ppm cc(STP)/(sec cm.sup.2 cm-Hg). A polymer dope comprising SIXEF.TM.-Durene in a solvent system containing N-methyl-2-pyrrolidone ('NMP') and an organic acid such as propionic acid ('PA') is prepared by polymerizing the polyimide monomers in NMP to form a polyamic acid polymer and imidizing this polymer using the acid anhydride. Water released from the polymer in the imidization reaction converts the anhydride to the organic acid. The dope is wet-spun into hollow fibers using a core solvent such as PA or glycerine; the fibers are coagulated in water.

SIXEF.TM.-durene polyimide hollow fibers

A breathable water-resistant fabric in which a surface of a fabric material is coated with a microporous layer of ETFE, and a process for making same. An ETFE dope containing a blend of ETFE and a binder polymer is cast or extruded into a film which is subsequently bonded or laminated to the fabric material. The binder is extracted to produce a microporous ETFE layer.

Breathable water-resistant fabrics

A composite fiber or film for use in a fluid separation membrane made of PAN coated with an intermediate permeable material and further coated with a selective layer. The PAN fiber or film is pre-wet with perfluoroether prior to being coated with the intermediate material, to produce a membrane material having enhanced permeability. The selective layer produces a high separation factor.

High performance pan composite membranes

A novel method for making a composite separation membrane, and the product of that method. This novel method includes applying one or more perfluoroethers to the surface of a microporous fiber or film made of a polymer such as PAN, and subsequently coating that fiber or film surface with a layer of selective material. This method provides a more permeable composite membrane than would be obtained by coating a fiber or film that had not been pre-wetted with perfluoroether.

Pan composite membranes

A process for coating a polypropylene or polyethylene surface with a maleic acid-grafted polypropylene or polyethylene copolymer. In this process, a dope containing the graft copolymer is applied to the polypropylene or polyethylene surface, e.g. by dip coating, at a temperature high enough to keep the copolymer solvated in the dope solvent. The surface is then dried to leave a porous graft polymer coating bonded to the polypropylene or polyethylene. The coated product has superior adhesion characteristics compared to uncoated polypropylene or polyethylene.

Process for surface-modifying polypropylene or polyethylene

A novel miscible blend of component polymers comprised of from about 5 weight percent to about 95 weight percent of a polybenzimidazole and from about 95 weight percent to about 5 weight percent of an aromatic polyamide, aromatic polyamide-hydrazide or aromatic polyamide containing heterocyclic linkages. Miscibility of the component polymers of the blend is indicated by infrared, X-Ray and Differential Scanning Calorimetry analyses and scanning electron photomicrographs. In a film or molded article of a blend mostly comprised of a polybenzimidazole, it is preferred that the aromatic polyamide, aromatic polyamide-hydrazide or aromatic polyamide containing heterocyclic linkages be present in the blend in an amount sufficient to result in a blend with improved tensile properties compared to the polybenzimidazole and that is more thermally processable than the polybenzimidazole. In a blend mostly comprised of an aromatic polyamide, aromatic polyamide-hydrazide or aromatic polyamide containing heterocyclic linkages, it is preferred that the polybenzimidazole be present in the blend in an amount sufficient to result in a blend with increased thermal stability and nonflammability compared to the aromatic polyamide, aromatic polyamide-hydrazide or aromatic polyamide containing heterocyclic linkages. The blends, particularly in the form of films or molded articles, may be post-treated with heat or sulfonating agent in order to minimize their shrinkage when subsequently subjected to heat and in order to increase their resistance to solvents and acids.

Blends of polybenzimidazoles and aromatic polyamides, aromatic

Fibers and fibrets of a novel miscible blend of component polymers comprising from about 5 weight percent to about 95 weight percent of a polybenzimidazole and from about 95 weight percent to about 5 weight percent of an aromatic polyamide, aromatic polyamide-hydrazide or aromatic polyamide containing heterocyclic linkages. Miscibility of the component polymers of the blend is indicated by infrared, X-Ray and Differential Scanning Calorimetry analyses and electron photomicrographs. In fibers or fibrets of a blend mostly comprised of a polybenzimidazole, it is preferred that the aromatic polyamide, aromatic polyamide-hydrazide or aromatic polyamide containing heterocyclic linkages be present in the blend in an amount sufficient to yield a blend with improved tensile properties compared to the polybenzimidazole and more thermally processable than the polybenzimidazole. The fibers or fibrets of the blend have a lower moisture regain than polybenzimidazole fibers or fibrets. In fibers or fibrets of a blend mostly comprised of an aromatic polyamide, aromatic polyamide-hydrazide or aromatic polyamide containing heterocyclic linkages, it is preferred that the polybenzimidazole be present in the blend in an amount sufficient to yield a blend with increased thermal stability and nonflammability compared to the aromatic polyamide, aromatic polyamide-hydrazide or aromatic polyamide containing heterocyclic linkages. The fibers or fibrets may be post-treated with heat or sulfuric acid in order to minimize their shrinkage when they are subsequently subjected to heat and in order to increase their resistance to solvents and acid.

Fibers and fibrets from blends of polybezimidazoles and aromatic

Asymmetric hollow fibers having a microporous hollow fiber core comprising a polyolefin, e.g. polypropylene, and an asymmetric coating comprising a fluoropolymer, e.g. SIXEF.TM.-Durene. Optionally, the coating may also comprise glycerine which is applied prior to the fluoropolymer. The fibers are coated by wet-spinning, or alternately by dry jet-wet spinning, through a spinning jet in which a fluoropolymer-containing fluid is applied to the outer surface of the fibers as they pass through the jet. The fibers exit the jet into a water bath. If greater selectivity is needed, the fiber later may be coated with an additional layer of a highly selective material, e.g. polyvinyl alcohol, PVP, and the like.

Asymmetric fluoropolymer-coated polyolefin hollow fibers

Asymmetric hollow fibers comprising a fluoropolymer, and a process for making such fibers. The hollow fibers are useful for making fluid separation membranes, especially gas separation membranes. In one embodiment of the process of this invention, a polymer dope having a viscosity of about 3000 poise or greater is prepared by solvating the polymer in a solvent system containing about 40%-90% N-methyl-2-pyrrolidone and about 60%-10% propionic acid by weight. The dope is dry-jet wet-spun into hollow fibers using a water-NMP core solvent. The fibers are coagulated in methanol. The fibers are then coated with a highly permeable material.

Fabrication of fluoropolymer hollow fibers for asymmetric membranes

A stable solution of polybenzimidazole resin containing from approximately 10 to approximately 35 weight percent of resins and from approximately 65 to approximately 90 weight percent of a suitable solvent, the resins consist of from approximately 70 to approximately 95 weight percent of polybenzimidazole and from approximately 5 to approximately 30 weight percent of polysulfone, wherein the solution is substantially free of organic salt. The solution is useful for the production of films, fibers and molded articles exhibiting enhanced mechanical properties.

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Randolph, NJ, United States of America

Tai-Shung Chung