Abstract: Cellulose ester fibrillar material is produced by forming a cellulose ester dope, pumping the dope to an extrusion orifice, extruding the dope through the orifice into a region of shear and high draw in a precipitation bath containing a non-solvent for said cellulose ester maintained at an elevated temperature. The fibrillar material is preferably subjected to further treatment to reduce the particle size and set the structure by expanding voids and expelling residual solvent. Paper having a high degree of opacity is produced by incorporating the cellulose ester material to obtain light weight paper.

Abstract: An improved neutralization process for use in the high speed spinning of an inorganic acid-containing polyamide spin dope.

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

Abstract: Water swellable absorbent articles, made from copolymers having a copolymerized crosslinker, together with methods for their preparation, and a composition containing a copolymerized crosslinker useful to make said articles are disclosed. The articles are crosslinked by heating and/or removing substantially all of the water from the precursor composition.The absorbent articles are useful as surgical sponges, diapers, tampons, meat trays, bath mats and the like.

Abstract: Water swellable polyacrylate articles are made from a solution of the polyacrylate having an effective amount of a soluble crosslinking agent therein by heating and/or drying the solution. The polyacrylate solution is made from a polyacrylate by saponification and the crosslinking agent is then added.

Abstract: A process for improving the adhesion to rubber of poly-1,3,4-oxadiozole filaments by applying compounds having at least one N-glycidyl group to the filaments. The products of the process and the use thereof in rubber articles are also disclosed.

Abstract: A method of making a drawn filament from a hot drawable poly-phenylene-1,3,4-oxadiazole having p-phenylene radicals or p-and m-phenylene radicals, with substituted bromine, wherein a solution of the polymer is dry jet wet spun into a coagulant, the filament washed and dried, and drawn at a temperature of at least 350.degree. C at a draw ratio of at least 6:1.

Abstract: A dry-wet process for forming interiorally asymmetric hollow fiber cellulose acetate membranes is disclosed.

Abstract: A preformed polybenzimidazole semipermeable membrane (e.g., a film or hollow filament) is chemically modified in accordance with the present invention. Imidazole groups of the polybenzimidazole membrane are cross-linked by reaction with a strong polybasic acid or its acid chloride (as defined). During the reaction the polybasic acid is dissolved in a relatively mild acid medium (e.g., glacial acetic acid) which serves to decrease the basicity of the imidazole groups and to promote the desired cross-linking reaction. The resulting cross-linked membrane is tougher than the untreated membrane and may be more readily handled without deleterious results. Also, the resulting cross-linked polybenzimidazole membrane no longer is soluble in N,N-dimethylacetamide, and exhibits improved service characteristics such as improved compaction resistance during prolonged usage at high pressure. The product of the present invention is particularly suited for use in separations from acid waste streams.

Abstract: A process for manufacturing fibers by a wet spinning procedure from an anisotropic dope of a polymer having aromatic mononucleus or polynucleus divalent radicals in which the chain extending bonds from each aromatic nucleus are coaxial or parallel and oppositely directed and which are connected by at least one link selected from --NHCO--, --NHCOCONH-- and --CONHNHCO-- is provided. The filaments taken out from a coagulation bath are, without applying any substantial tension thereto, washed with water, dried and optionally heat-treated, on a conveyor. The resulting fibers possess moderate initial modulus and elongation as well as high tenacity.

Abstract: In the method of this invention a substantially linear polyurethane filament is elongated a number of times its original length and heated at a temperature above its "fiber stick temperature" for a sufficient time so that the filament permanently retains that elongation and does not recover any substantial amount of the length to which it has been elongated.

Abstract: A nonwoven mat of polyolefin fiber is contacted with a gaseous sulfur dioxide-chlorine mixture to sulfo-chlorinate the surface of the polyolefin fibers to a relatively high sulfur content and then preferably treated with an amine, either after compacting the mat or before compacting the mat to form a structure suitable as a battery separator. The mat can be used for other structures besides battery separators. And it can be separated into individually wettable staple fibers before compaction, i.e. individual separate fibers which are wettable.

Abstract: In a process for forming fibers by extruding a spinning dope successively through a layer of inert gas and a tube immersed in a coagulating bath, the tension profile of the yarn passing through the tube is regulated by regulating the pressure of the layer inert gas. In this pressurized quench system, the coagulating liquid is maintained at a predetermined level, despite transient changes in liquid input, by passing both pressurized gas and coagulating liquid through a pipe having an opening at the level to be maintained.

Abstract: Fibers and yarn and a process for preparing them comprising dissolving in concentrated sulfuric acid a polymer containing at least 75 mol percent of an aromatic poly-(1,3,4-oxadiazole) having the repeating structural formul a ##SPC1##In which Ar is ##SPC2## the benzene rings in A or B being substituted or unsubstituted; the linking bonds in A being situated m- or p- with respect to each other, and in B situated m- or p- with respect to X; X being --SO.sub.2 -- or --CO--; and n being 1 or 2. The solution is then spun through a spinneret into a substantially water-free precipitating medium of at least one liquid having the formula (II) ##EQU1## IN WHICH R.sub.1, R.sub.2 and R.sub.3 may be the same or different and are alkyl groups having 1 to 4 carbon atoms, and R.sub.3 may also be H, and in which R.sub.1 and R.sub.2 or R.sub.1 and R.sub.3 may together comprise a divalent alkylene radical, the total number of carbon atoms in R.sub.1, R.sub.2 and R.sub.

Abstract: Limpid solutions suitable for making filaments and sheets of mostly aromatic polyamides are obtained by precondensation of the initial materials up to a conversion rate of from 80 to 98% in a solvent, neutralization with ammonia, separation of the insoluble ammonium halide, addition of an inorganic base, evacuation of the ammonia set free, subsequent after condensation and neutralization of the hydrogen halide newly formed.The spinning solutions prepared according to this process are stable and limpid and are excellently suitable for the preparation of shaped articles.

Abstract: Poly(N-acetyl-D-glucosamine) is soluble in hexafluoroisopropyl alcohol and hexafluoracetone sesquihydrate. The solutions formed may be wet or dry spun into filaments, or cast into films or solid articles, which may be used as absorbable surgical sutures, or other absorbable surgical elements. Poly(N-acetyl-D-glucosamine) is enzymatically degradable in living tissue, and is resistant to hydrolytic degradation, and, therefore, surgical elements thereof have good storage characteristics under a wide variety of conditions.

Abstract: New polymeric materials in the form of fibers and films composed of polyvinyl alcohol, polyvinyl chloride and a water-soluble amido-polymer having a portion of the polyvinyl chloride grafted thereon and which contains at least about 80 mole percent amido or methylolated amido groups. These materials possess excellent light and heat resistance.Also disclosed is a process for preparing these materials comprising adding a water-soluble catalyst and emulsifier to an aqueous solution of the amido-polymer and subjecting the mixture to emulsion polymerization with added vinyl chloride. Thereafter, polyvinyl alcohol is added as a matrix to the emulsion to make a dope which is then coagulated.CROSS REFERENCE TO RELATED APPLICATIONSThis application is a division of application Ser. No. 348,069, filed Apr. 5, 1973, now U.S. Pat. No. 3,887,676, which in turn was a continuation-in-part of application Ser. No. 230,478, filed on Feb. 29, 1972, and now abandoned, which in turn was a continuation of application Ser. No.

Abstract: Polyurethane elastomeric filaments of improved physical properties and chemical resistance prepared by preforming the filamentary material such that the polyurethane contains at least about 100 up to about 700 milliequivalents/kilogram of reactive terminal amino groups, and then aftertreating this preformed filamentary polyurethane, optionally under simultaneous stretching, with an organic polyisocyanate and then preferably heating the treated material at an elevated temperature above about 140.degree.C. The polyurethane filamentary product is particularly useful in providing durable elastic filaments, fibers, threads, yarns, fabrics and similar textile materials.

Abstract: The invention concerns new difficulty inflammable polyesteramide filaments, threads, fibers and films.These filaments, threads, fibers or films consist of a polymer obtained from the reaction of at least one aromatic diisocyanate and aromatic diacids, at least one of said diacids containing one or more ester groups.These new yarns, fibers and films are employed in all fields in which properties of low inflammability are desired.

Abstract: Aromatic polyamide-hydrazide films, consisting of p-benzamide p-phenylene terephthalamide and/or terephthaloyl hydrazide recurring units, as major chain constituents, are removed from inorganic residue by an aqueous mixture which dissolves or swells the films, and are heated up to their crystallization temperatures in tension, giving rise to high tensile strength and modulus, good hygroscopic dimensional stability and excellent electrical insulation properties.

Abstract: A process of making polyvinylidene fluoride yarns and fibers of homogeneous structure and good dry strength includes the steps of spinning the solution of the polymer into a coagulating bath containing 45 to 60% by weight aprotic polar organic solvent and 40 to 55% by weight water, stretching the filaments in air to a ratio of 1.5 to 5x and then in boiling water to a ratio of 1.5 to 4x (overall stretching ratio of 3x to 6.5x) and then washing in water at room temperature.

Abstract: A method for producing fibers and films comprising emulsion polymerizing a polyvinyl alcohol derivative having sulfone or sulfate group with a chlorine-containing vinyl monomer, adding the thus formed emulsion to a matrix of polyvinyl alcohol and then coagulating the mixture into a film or fiber. The resulting polymeric compositions are composed of polyvinyl alcohol, the sulfone or sulfate-containing polyvinyl alcohol and the chlorine containing vinyl polymer, in which a part of the chlorine-containing vinyl polymer is grafted onto the polyvinyl alcohol derivative. The emulsions used possess excellent stability and the films and fibers therefrom possess excellent heat resistance.

Abstract: Disclosed is a process for fabrication of elastomer or plastomer tubes from sensitized aqueous dispersions wherein the tube is extruded through a shaping apparatus. Heated air is discharged into the tube as it is extruded, with the heated air flowing axially through the tube to vaporize and remove serum exuded into the tube as the gelling process continues. The tube, having the heated air flowing therethrough may be passed through a washing vat to remove serum from its external surface.

Abstract: Water-insoluble, water-swellable fibers adapted to bind aqueous fluids such as body exudates are prepared by spinning fibers from an organic solvent solution of a copolymer of maleic anhydride with suitable vinyl aromatic monomers. The copolymer solution also contains a small amount of a polyfunctional cross-linking agent such as an adduct of glycerine with ethylene oxide and propylene oxide which reacts to cross-link and plasticize the copolymer chains when the fibers are heated and dried. The cross-linked copolymer fibers are then rendered hydrophilic and water-swellable by reaction with ammonia.

Abstract: High modulus, high tenacity aromatic polyhydrazide fiber composed ofA. a polyterephthal hydrazide unitB. a poly p-benzamide unit andC. a poly p-phenylene terephthalamide unit, and method of making same.

Abstract: Method for the production of water swellable, lightly crosslinked, hydrogel polymer tapes or fibers comprises extruding an isocyanato terminated prepolymer of a poly(alkyleneoxy) polyol and an organic diisocyanate into a coagulant or crosslinking bath containing water or organic polyamine as the crosslinker.

Abstract: Microporous polyurethane hydrogels of high water swellability comprising lightly crosslinked polymers of isocyanate terminated prepolymers which are the reaction product of (i) poly(alkyleneoxy) polyol with (ii) organic diisocyanate that has been lightly crosslinked with (iii) water or an organic polyamine are produced by impregnating the isocyanato terminated prepolymer solution prior to contact with the crosslinking agent with a minor significant amount of a liquid non-solvent.

Abstract: Amine-ended poly(p-phenylene terephthalamide) gives improved spinning results.

Abstract: A process for preparing high molecular weight aryl alkyl polymers is disclosed, wherein oxalic acid and paraphenylene diisocyanate are reacted in substantially stoichiometric amounts in a polar, aprotic anhydrous organic solvent at a temperature which is raised progressively at a rate of about 1 to about 5.degree.C per minute from a lower temperature of about 0.degree. to 30.degree. C to a higher temperature of about 80.degree. to about 150.degree.C in the presence of, at least when the viscosity of the reaction mixture exceeds 6,000 poises, a viscosity reducing amount of a hydrogen bond breaking agent, such as lithium chloride.The resulting polymers can be formed into filaments, fibers and films, and the filaments exhibit improved tensile strengths and modulus of elasticity as compared to similar filaments of other arylalkyl polymers based on oxalic acid and other aromatic diisocyanates.