Abstract: A method to prepare high strength high modulus polyolefin shaped articles comprising forming a heated solution of the polyolefin from particles of which about 75 to 100% by weight have a particle size of from about 100 to about 400 microns and having a weight average molecular weight of from about 300,000 to 7,000,000, then shaping the heated soltion then cooling the shaped solution. To further increase the strength of the article it can be stretched.

Abstract: Conducting articles such as fibers, films, tapes and the like are fabricated from intractable conducting polymers such as polyacetylene. The articles are prepared by (a) forming a gel of a carrier polymer in a compatible solvent, (b) polymerizing, within the gel, a selected monomer, and (c) doping the article so provided. The articles are highly electrically conductive as well as mechanically quite strong.

Abstract: This invention relates to a novel composition useful for preparing a semi-permeable cellulose ester gas separation membrane, which composition includes a mixture of a cellulose ester, a solvent selected from the group consisting essentially of glycerol acetate, glycerol diacetate, glycerol triacetate, and mixtures thereof, and optionally the non-solvent glycerol. This invention also relates to a process of fabricating a cellulose ester gas separation membrane from said composition.

Abstract: A process for preparing high modulus, high tenacity fibers of aromatic polyamide wherein a first constant tension within 40-95% of the fiber breaking load is applied to washed fibers at a temperature of less than 50.degree. C. for a duration of greater than 5 seconds, and drying the fibers at a second constant tension which is from 10-100% of the first constant tension and at a temperature of more than the temperature of the first constant tension and less than 350.degree. C. until the fibers have a moisture content of about 2 to 10%.

Abstract: A method of extracting a material from a continuous running length of fiber comprising continuously moving the fiber through a conduit while simultaneously flowing a solvent for the material through the conduit with the conduit having a length and cross sectional area sufficient to facilitate extraction of the desired amount of the material. The flow is countercurrent to the movement of the fiber.

Abstract: Provided is a molecular composite comprising a rigid-rod aromatic heterocyclic polymer, a flexible, coil-like thermoplastic polymer and a thermosetting polymer.Also provided is a method for fabricating a molecular composite film or fiber which comprises the steps of forming a biphasic, stir opalescent solution of a rigid-rod aromatic heterocyclic polymer, a thermoplastic polymer, a thermosetting polymer and a solvent which is common to the three polymers, adding solvent to the solution until the solution becomes isotropic and stir opalescence has ceased to determine the critical concentration of polymers in the solvent, adding additional solvent to the solution so that the polymer concentration is below the critical concentration, extruding the solution into a non-solvent for the polymers to form the desired film or fiber, drying the film or fiber and hot drawing the film or fiber at a temperature above the Tg of the thermoplastic, but below the polymerization temperature (Tpoly) of the thermosetting resin.

Abstract: This invention discloses a process for producing a high modulus, high tenacity polyethylene terephthalate filament which comprises (1) spinning a solution of polyethylene terephthalate in an organic solvent through a die to produce a solution spun filament, wherein the polyethylene terephthalate has an intrinsic viscosity of at least about 3.

Abstract: A process for the preparation of a porous hollow filament composed mainly of an organic polymer, which comprises separately feeding a powder of the organic polymer and a liquid additive to a feed zone of twin-screw extruder, mixing the polymer with the additive in a kneading zone of the extruder to form a substantially liquid mixture, further kneading and compressing the liquid in a kneading and compressing zone of the extruder, feeding the liquid to an extruding zone of the extruder, and extruding the liquid from the extruding zone.

Abstract: Polyacrylonitrile articles, such as filaments, tapes and films, having high tensile strength and modulus, and prepared by adding to a solution of polyacrilonitrile with a molecular weight above 3.times.10.sup.5, preferably above 5.times.10.sup.5, a minor amount of a bivalent metal compound, converting the solution into a solvent containing article, cooling this article to form a gel article, removing from this gel the solvent and metal compound, and stretching the resulting article at increased temperature. With this process filaments with a tensile strength above 1.2 GPa and a modulus above 16 GPa can be obtained.

Abstract: A process for preparing microporous poly(etheretherketone)-type fibers comprising forming an extrusion mixture of at least one unsulphonated poly(etheretherketone)-type polymer and a solvent comprising at least one organic compound consisting predominantly of carbon and hydrogen, wherein the organic compound has a molecular weight of between about 160 and 450, contains at least one six membered aromatic ring structure, possesses a boiling point of between about 240 and 480 degrees Celsius, and is capable of dissolving at least about 10 weight percent of the poly(etheretherketone)-type polymer present at the extrusion temperature, extruding to form solid or hollow fibers, conveying the fibers through at least one quench zone, conveying the fibers through at least one leach zone, and drying the fibers, wherein the fibers so formed possess interconnecting or non-interconnecting pores.

Abstract: A process for producing a shaped article of polyamide which comprises (1) melt-shaping an intimate mixture of 100 parts by weight of a polyamide having hexamethylene terephthalamide as main recurring units and 20 to 500 parts by weight of an aromatic hydroxy compound, and then (2) removing the aromatic hydroxy compound from the resulting shaped article by extraction.

Abstract: A process is provided for preparing high strength polymetaphenylene isophthalamide fibers by the steps which include extruding a dope solution of a metaphenylene isophthalamide polymer in an organic solvent through a spinneret and into a coagulating liquid form in undrawn polymer filament; adjusting the content of the organic solvent; carrying out a first wet drawing in at least one aqueous wet drawing bath; making a second adjustment of the content of the organic solvent; carrying out a second wet drawing at a specified draw ratio in at least one aqueous wet drawing bath; drying the second wet drawn filament; and dry drawing the dried filament.

Abstract: Methods for fabricating low dimensionally electroconductive articles comprising cofacially stacking organomacrocycles and as cofacially stacking phthalocyanines, in which a composition comprising a cofacially stacking phthalocyanine in strong Bronsted acid is formed into a desired shape such as a fiber or film, solidified by removal of the solvent, and provided in fractional valence state.

Abstract: Composition (M) having a base of a cellulose ester having formate groups, this composition being an anisotropic solution containing:(a) the cellulose ester;(b) formic acid;(c) at least one phosphoric acid.A process for obtaining this composition by dissolving the cellulose and a process for obtaining articles by transformation of this composition, and, for example, regenerating the cellulose of these articles. A cellulose fiber is provided in which a degree of substitution of the cellulose by formate groups is either at least equal to 2% or is zero or less than 2%.

Abstract: Polyvinyl alcohol articles of high strength and modulus are obtained by thermoreversible gelation of a polyvinyl alcohol solution, extraction of the gelation solvent using a mixture of a low alcohol or ketone and water, followed by high stretching. Preferably, a mixture of 5-80 vol. % of acetone and 95-20 vol. % of water is used as extractant. With this process extraction times of only 3-10 minutes are required.

Abstract: High modulus and high strength articles of polyvinylalcohol are obtained by thermoreversible gelation of a 5-50 wt. % solution of a polyvinylalcohol with an M.sub.W of 2.5.times.10.sup.4 to 5.times.10.sup.5 in water, followed by solvent removal and high stretching.Pref. gelation is obtained by cooling to a temperature of at least 40.degree. C. below the gelation temperature.With this process low costs of solvent removal and regeneration are obtained.

Abstract: A process for diffusing and subliming water-soluble and water-insoluble materials into never-dried, water-swollen aromatic polyamide fibers, using steam heated at certain temperatures.

Abstract: A skinless hollow fiber of a cellulose ester material is formed by providing an aqueous coagulation bath having a tube-in-ring jet immersed therein and extruding a spinning solution comprising at least one cellulose ester material and a solvent therefor directly into the bath through an annulus surrounding the tube of said tube-in-ring jet while simultaneously allowing a portion of the liquid in the bath to be autogenously aspirated through an opening in the tube, located below the surface of the liquid in the bath, and through the tube thereby forming a lumen in the extruded fiber and then drying the extruded fiber.

Abstract: A micro-porous membrane of ultra-high-molecular-weight alpha-olefin polymer having a weight-average molecular weight greater than 5.times.10.sup.5, the micro-porous membrane having through holes 0.01 to 1 micrometer in average pore size, with a void ratio from 30 to 90% and being oriented such that the linear draw ratio in one axis is greater than two and the areal draw ratio is greater than ten. The micro-porous membrane is obtained by forming a gel-like object from a solution of an alpha-olefin polymer having a weight-average molecular weight greater than 5.times.10.sup.5, removing at least 10 wt % of the solvent contained in the gel-like object so that the gel-like object contains 10 to 90 wt % of alpa-olefin polymer, orientating the gel-like object at a temperature lower than that which is 10.degree. C. above the melting point of the alpa-olefin polymer, and removing the residual solvent from the orientated product.

Abstract: A hollow fiber membrane of a cellulose ester for dialysis of body liquids, such as blood, and a method are described. The membrane, which has a membrane thickness of less than 20.mu., and a yield strength S.sub.b (g/filament) after heat-treatment at 80.degree. C. for 20 hours satisfies the following formula (I):0.90.ltoreq.S.sub.b /S.sub.a .ltoreq.1.10 (I)wherein S.sub.a represents the yield strength (g/filament) of the hollow fiber membrane which is measured before heat treatment. The membrane has excellent dialysis performance while keeping excellent storage stability and excellent UFR retention during storage and during hemodialysis. A spinning solution of a cellulose ester is extruded through cyclic slits around an inner tube of a spinneret while a core solution is simultaneously extruded through the inner tube of the spinneret.

Abstract: Solutions of intermediate molecular weight polymers from about 200,000 to about 4,000,000, such as polyethylene, in a relatively non-volatile solvent are extruded through an aperture at constant concentration and thereafter stretched at a ratio of at least about 3:1 prior to cooling to form a first gel. The first gels are extracted with a volatile solvent to form a second gel, and the second gel is dried to form a low porosity xerogel. Stretching occurs with any one or more of the first gel, second gel or xerogel. The polyethylene products produced by our process include products having a molecular weight between about 200,000 and about 4,000,000 a tenacity of at least about 13 grams/denier, a modulus of at least about 350 gram/denier, a porosity of less than 10% by volume, a crystalline orientation function of at least about 0.95, and a main melting temperature of at least about 140.degree. C.

Abstract: Polyacrylonitrile (PAN) fiber of high strength (tensile strength.gtoreq.20 g/d) produced from a polymer composed mainly of acrylonitrile (AN) and having a weight average molecular weight not less than 400,000, and a method of producing said fiber characterized by a multistage stretching step and a drying step under particular conditions.

Abstract: Solutions of ultrahigh molecular weight polymers such as polyethylene in a relatively non-volatile solvent are extruded through an aperture at constant concentration through the aperture and cooled to form a first gel of indefinite length. The first gels are extracted with a volatile solvent to form a second gel and the second gel is dried to form a low porosity xerogel. The first gel, second gel or xerogel, or a combination, are stretched. Among the products obtainable are polyethylene fibers of greater than 30 or even 40 g/denier tenacity and of modulus greater than 1000 or even 1600 or 2000 g/denier.

Abstract: A device for monitoring the filling level of the degassing space in an extruder used for processing thermoplastic materials comprises a level detection orifice located in the degassing dome or jacket of the extruder which opening is connected to a conduit. The conduit leads through a regulator device to a gas source. Connected to the conduit, between the regulator device and the orifice, is a pressure sensor such as a pressure difference switch. If the level of molten material in the dome rises above a preselected level, it blocks the opening and produces a back-pressure in the conduit. The switch is automatically actuated by this back-pressure and produces a signal. Appropriate action can then be taken to prevent the further rise of the molten material in the dome and to prevent blockage of the degassing device.

Abstract: The present invention relates to a process for producing an of aromatic polyimide film comprising (A) casting on a support a dope containing an amide-type polar solvent and 10-45 weight percent of a polyamic acid having more than 0.4 dl/g an inherent viscosity of more than 0.4 dl/g, (B) concentrating the polymer content to be at least higher than that of the initial dope while simultaneously raising the ring closure ratio above 30%, (C) removing the solvent from the film by extraction in an aqueous medium so as to lower the solvent content of the film below 10% and (D) then heating the film to a temperature of more than 200.degree. C.The process of the present invention is useful for the production of aromatic polyimide film having a reduced rate of solvent decomposition and improved productivity.

Abstract: Fibers prepared by spinning, drawing and drying dilute solutions of ultrahigh molecular weight polyethylene or polypropylene are modified by including in the dilute solution a polymeric additive. The polyethylene fibers so prepared have melting points above 140.degree. C. and exhibit improved adherence to matrices, resistance to fibrillation and other advantageous properties. Additives include lower molecular weight polyolefins, oxidized polyolefins, olefin copolymers, polyolefin graft copolymers and polyoxymethylenes.

Abstract: Polyvinyl alcohol of molecular weight over 500,000 (i.e. 1,500,000 to 2,500,000) is spun as a dilute solution (2-15%) in a relatively non-volatile solvent such as glycerin. The resultant gel fiber is extracted with a volatile solvent such as methanol and dried. Upon stretching at one or more stages during the process, fibers of tenacity above 10 g/denier and modulus above 200 g/denier (e.g. 18 and 450, respectively) are produced.

Abstract: The invention relates to the preparation of filaments with a high tensile strength and a high modulus and to the filaments thus prepared. A solution of a linear polyethylene with a weight-average molecular weight of at least 4.times.10.sup.5 is spun and the filaments, from which the solvent may have been removed in whole or in part, are drawn using a draw ratio of at least (12.times.10.sup.6 /M.sub.w)+1. The filaments are drawn at a temperature such that the modulus is at least 20 GPa.The invention allows filaments to be prepared at high drawing rates, of 0.5 sec.sup.-1 or more, with a modulus of at least 20 GPa and a tensile strength of at least 1 GPa.

Abstract: A poly-p-phenylene-terephthalamide fiber with excellent fatigue resistance resulting from a unique combination of properties. The fibers are prepared by extruding an anisotropic polymer dope in a non-coagulating layer, passing the extrudate through a coagulating layer, depositing the resulting coagulated fibers on a net conveyor, and in the absence of substantial tension sequentially washing the fibers, holding the fibers in saturated steam, and drying the fibers under specified conditions.

Abstract: Processes for wet spinning nylon 4 filaments. The processes are characterized by the use of a formic acid spinning dope and an acidic aqueous alkali metal formate coagulation bath maintained at elevated temperatures.

Abstract: New polymer solutions, processes for producing such solutions, shaped articles made from these solutions, and process of making such articles, are disclosed. The polymer solutions contain cellulose having a degree of polymerization of at least 200, an acrylonitrile polymer, dimethylsulphoxide and formaldehyde. The weight ratio of cellulose/acrylonitrile polymer is 0.05 to 1, preferably 0.1 to 1, the weight ratio of formaldehyde/cellulose is 0.2 to 2, and the total concentration of polymer in the solution is 12 to 30% by weight, preferably 18 to 26% by weight.The solutions of the present invention are particularly suitable for the production of filaments consisting of fibrils orientated approximately along the axis of the fibre and closely interwoven, with the cellulose macromolecules being partially involved in a crystal lattice characteristics of cellulose II. The filaments possess valuable properties for use in textiles, such as, for instance, in garments.

Abstract: Process for production of a hollow fiber semipermeable membrane which can selectively separate the components of solution or gas mixtures, which consists essentiallly of dissolving cellulose triacetate and an organic acid and optionally a polyether in N-methyl-2-pyrrolidone to give a spinning solution having fixed contents of cellulose triacetate and organic acid and polyether (if any), and extruding the spinning solution through a spinneret into a gaseous atmosphere and immersing the spun fibers in an aqueous coagulation bath. The hollow fiber semipermeable membrane has excellent permeability and excellent separation characteristics with good life and hence is useful for various techniques such as dialysis, ultrafiltration, reverse osmosis, and separation of gases.

Abstract: Aromatic polyimide fibers having an enhanced mechanical strength are produced by a process comprising the steps of: preparing a spinning dope solution of at least one aromatic polyimide having 90 molar % or more of a recurring unit of the formula (I): ##STR1## wherein R is a divalent aromatic radical, in a phenolic solvent; converting the dope solution into at least one filamentary stream thereof; solidifying the filamentary dope solution stream by removing the solvent therefrom to provide at least one undrawn filament, and; drawing the undrawn filament at a temperature of 20.degree. to 600.degree. C. at a draw ratio of 1.5 to 5.0.

Abstract: A hollow fiber membrane made of an ethylene-vinyl alcohol copolymer is provided, which is characterized in that, when observed in a dry state with an electron microscope, the hollow fiber membrane has at least one dense, active layer (or skin layer) on the inside and/or outside surface thereof and further a three-layered structure comprising two layers respectively contacting the inside and outside surfaces and each consisting of a plurality of particles bonded together and having particle sizes of 0.01 to 2 microns and a substantially particle-free homogeneous layer lying between the two layers.

Abstract: Cellulose is activated by penetration of the cellulose with a polar medium and mixed at a temperature at which no significant degradation occurs with an amide selected from the group consisting of dimethylacetamide, 1-methyl-2-pyrrolidinone and mixtures thereof and from 3 to 15% by weight of lithium chloride. The cellulose is then dissolved in the amide and lithium chloride in the substantial absence of any polar medium other than the amide. Shaped cellulosic products may be formed by reconstituting the cellulose in fiber, sheet or other form.

Abstract: A process for making polymer filaments which have a high tensile strength and a high modulus by stretching a polymer filament which contains an appreciable amount of polymer solvent at a temperature between the swelling point and the melting point of the polymer.

Abstract: A wholly aromatic polyamide shaped article is prepared by a process wherein a solution of a wholly aromatic polyamide is extruded through an orifice and introduced into a first coagulating bath comprising an aqueous coagulating liquid and, then, the coagulated extrudate is introduced into a second coagulating bath comprising an aqueous solution of an inorganic salt.

Abstract: A method of manufacturing a hollow fiber which comprises providing a spinning solution of a water miscible organic solvent and a high molecular weight compound which may be polyacrylonitrile, a copolymer of acrylonitrile, alpha cellulose, a cellulose ester, polymethylmethacrylate, poly vinyl chloride, or poly-.gamma.-benzyl glutamate. This spinning solution is extruded through an annular slit while simultaneously, an alkaline or acid aqueous salt solution is extruded from an orifice encircled by the annular slit. The aqueous salt solution has a salt content of 15 to 50% by weight and there is sufficient alkali or acid present in the aqueous salt solution to effect controlled hydrolysis of the high molecular weight compound.

Abstract: A method of manufacturing a hollow fiber which involves preparing a spinning solution of a non-polar water miscible organic solvent and a high molecular weight organic compound consisting of cellulose esters, polymethylmethacrylate, polyvinyl chloride, or poly-.gamma.-benzyl glutamate, extruding the solution through an annular slit, and simultaneously extruding a neutral aqueous salt solution from an orifice encircled by the slit, the solution having a salt content of 15 to 50% by weight and being capable of developing a phase separation with the water miscible organic solvent by means of a salting out effect. The extruded spinning solution is passed substantially downwardly in a vertical direction into an aqueous coagulating bath, the annular slit being separated from the bath by at least 5 mm, the distance being sufficient to cause significant evaporation of the solvent from the spinning solution.

Abstract: Continuous film production from a high pressure feed stream is achieved in a system which provides methods and means for maintaining pressurized gas in an extrusion zone wherein the extrudate may be cooled to form a solid polymeric film. The product film is withdrawn from the extrusion zone continuously through a standing liquid column in fluid communication with the extrusion zone. The film is passed downwardly into a liquid leg below the extrusion zone and upwardly through the liquid column, which has an upper exit end elevated above the pressurized zone thereby exerting super-atmospheric pressure. The product is recovered from the liquid sealing medium, advantageously water, at ambient pressure. Hot aqueous solutions of polyacrylonitrile may be extruded at elevated pressure onto a cooled casting drum in a gaseous environment wherein flashing of the hot solvent is prevented.

Abstract: A process for the manufacture of fibres from a polyamide entirely or substantially consisting of poly-p-phenylene terephthalamide, by spinning a spinning mass having a temperature of 20.degree.-120.degree. C. and consisting of a mixture of concentrated sulphuric acid having a strength of at least 96% by weight and, calculated on the weight of the mixture, at least 15% of polyamide having an inherent viscosity of at least 2.5, the spinning mass being downwardly extruded into a coagulation bath from a spinneret whose efflux side is positioned in a gaseous inert medium and shortly above the liquid surface of the coagulation bath. The spinning mass is prepared by the successive steps of cooling the concentrated sulphuric acid to below its solidifying point, combining the sulphuric acid thus cooled and the polyamide, intermixing the two substances into a solid state mixture and heating the resulting solid state mixture to spinning temperature.

Abstract: Water absorbent articles, made from solutions of carboxylic polyelectrolytes, together with methods for their preparation, and a composition useful to make said articles are disclosed. The articles are cured and/or crosslinked with monomeric amine-epihalohydrin adducts by heating and/or removing substantially all of the solvent from the precursor composition.The absorbent articles are useful as surgical sponges, diapers, tampons, meat trays, bath mats and the like.

Abstract: Orientation stretching of acrylonitrile polymer fiber spun from a polymer-water melt directly into a steam-pressurized solidification zone is more readily accomplished when hot, liquid water is used to wet the fiber being processed at or before the stretch rolls.

Abstract: An improved process for the production of ultralow denier, high-strength polybenzimidazole filaments is provided. A solution of the polymer is extruded vertically downward through a plurality of extrusion orifices into a gaseous atmosphere before being passed through a liquid coagulation bath. During their passage from the extrusion orifices to the exit from the coagulation bath, the filaments are drawn at an initial draw ratio of approximately 2:1 to 50:1. After being passed through the coagulaton bath, the filaments are washed, dried, and heat drawn at a heat draw ratio of approximately 1.5:1 to 10:1. The resulting filaments, having a denier per filament of approximately 0.05 to 0.50 and a tenacity of at least 4 grams per denier, are collected.

Abstract: A method is disclosed for embedding sequestering agents in filamentary structures, the method comprising the steps of preparing an emulsion formed by an aqueous or nearly aqueous solution of the sequestering agent and a solution of the filament-forming polymer in an appropriate solvent, and spinning the emulsion in a coagulation bath.

Abstract: This invention relates to a process for treating the surface of cellulosic shaped products such as fibers, films filaments, yarns and the like, formed from a spinning dope of a solution of cellulose in amine oxide, by applying to the surface of the product a nonsolvent liquid that will reduce the solvent action of the amine oxide for cellulose at the surface of the product.

Abstract: The invention relates to a process for the production of hydrophilic filaments or fibres having a sheath/core structure, a porosity of at least 10% and a water retention capacity of at least 10% and having a fibre swelling factor which is lower than the water retention capacity. The process is carried out by spinning a solution of a fibre forming synthetic polymer, especially an acrylonitrile polymer by the dry jet wet-spinning method wherein immediately on leaving the spinning jet and prior to coagulation in the precipitation bath the filaments or fibres are contacted with steam or with the vapor of another liquid which coagulates the filaments.

Abstract: A solution containing cellulose dissolved in a tertiary amine N-oxide solvent containing a nonsolvent for cellulose such as water is shaped by extrusion or other shaping process to form a shaped cellulose fiber, rod, plate, tubing or film. The extruded shaped article is stretched in air while still a solution to impart improved physical properties thereto and the cellulose is precipitated from the shaped solution to set the properties without additional drawing. The solution may be prepared by dissolving cellulose in the tertiary amine N-oxide solvent in the barrel of an extrusion apparatus, extruding the solution, orienting by stretching the resulting product in air while still a solution and then precipitating the cellulose from the shaped article before significant degradation of the cellulose. The cellulose and tertiary amine N-oxide may be ground to substantially the same particle size before charging the extruder barrel.

Abstract: The invention concerns a membrane filtration type hollow fiber. It is composed of a single material phase which material is a chain high polymer such as cellulose acetate and capable of forming fibers by the spinning of the high polymer. The cylindrical wall defining the hollow fiber represents a three-dimensional net-like structure of fine filtering passages. This structure occupies substantially the whole mass of the tubular wall or a closed ring band zone when seen in any cross-section of the wall, providing thus an effective and active filtering zone. The pore rate amounts to at least 55%, and active points of the filtering passages for governing minimum passable sizes of the passages for solids included in a filtering liquor to be treated upon are distributed at random throughout at least the active zone. These sizes are nearly uniform.

Abstract: A method of preparing shaped polypyrrolidone articles having a high degree of tensile strength comprising forming said articles from solutions of polypyrrolidone in hydrous formic acid and drawing said articles while impregnated with said hydrous formic acid. The invention also includes the step of enhancing the tenacity of shaped polypyrrolidone articles by impregnation thereof with hydrous formic acid and drawing said impregnated articles.