Abstract: A process for preparing pitch for matrix wherein an optically isotropic pitch is formed into a fibrous pitch, and the fibrous pitch thus obtained is nitrated with a nitration reagent in the presence of an acid catalyst. The resulting pitch can be carbonized with a low energy, is high in carbonization yield, low in softening point and excellent in moldability and impregnability.

Abstract: Apparatus for producing a three-dimensional model including apparatus for depositing, layer upon layer, a photopolymer material in a selectable configuration and apparatus for curing each photopolymer layer following deposition thereof and prior to deposition thereon of a succeeding layer of photopolymer.

Abstract: A system responsive to coordinate information for automatically providing a three-dimensional physical model of a desired geometry and comprising apparatus for selectably solidifying a solidifiable material on a sequential layer by layer basis characterized in that following selectable solidification of a given layer, the non-solidified portions thereof are removed and replaced by a removable support material which is not solidifiable under the same conditions as the solidifiable material.

Abstract: A sheath core fiber having an inner continuous core made from an oriented thermoplastic material, such as polyester, nylon, acrylic, and olefin, and a sheath made of a nonthermoplastic material, such as regenerated cellulose and protein. The fiber maintains the crease and tear resistance of the core material, yet has the water sorptivity and dyeability of the sheath material.A method of manufacturing such a fiber is also disclosed.

Abstract: A process for fabricating a composite in the form of a network of microfibrils which includes interpenetrating the microfibrils with a matrix material to form a composite which includes two continuous interpenetrating phases, a matrix-material phase and a microfibrillar-reinforcing-network phase.

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: A wet and dry jet wet spinning process produce one or a plurality of siliceous-containing fibers. At least a partial hydrolyzate is formed from silicon alkoxides and/or colloidal dispersions of hydrolyzable metal oxides through acid catalyzed hydrolysis in the presence of a solvent. The ratio of amounts of the water to silicon alkoxide or hydrous oxide is around 1.5 to 1 up to less than around 4 to 1. Both the hydrolysis and polymerization reactions produce an ungelled hydrolyzate with a viscosity in the range of 70 to greater than 1000 poise. This hydrolyzate is extruded through a spinnerette into a gaseous environment for dry jet wet spinning followed by contacting with a nonsolvent liquid or directly into a nonsolvent liquid for wet spinning. The contacting with the nonsolvent liquid is for effective coagulation to produce cohesive fiber that may have some stickiness. The fiber is removed from the nonsolvent liquid where the fiber's length is continuous from the spinnerette to removal.

Abstract: Alkyldiamine, 1,3,5-trihydroxybenzene or 1,3-dihydroxybenzene is added as a copolymerization component to a polyfunctional aromatic amine component in the amount of 1-20% by weight with respect to the polyfunctional aromatic amine in producing a composite semipermeable membrane by laminating on a microporous substrate a polyamide formed by interfacial polycondensation between a polyfunctional aromatic amine and a polyfunctional acid halide. The composite semipermeable membrane has improved oxidation resistance while retaining excellent separation selectivity and high permeability of the crosslinked polyamide-based composite semipermeable membrane. The composite semipermeable membrane is used for desalination of brackish and sea water.

Abstract: A sol gel reaction process for forming glassy articles involves the hydrolysis of silicon alkoxides with or without additional dispersions of hydrated silicon oxides, and polymerization including crosslinking. The present process involves forming glassy articles by the sol gel reaction route utilizes coagulation promoters having fatty acid hydrophobic moieties and hydrophilic moieties of primary, secondary, tertiary amines or quaternary ammonium compounds. The coagulation promoter catalyzes either and/or both of the hydrolysis and polymerization reactions. The coagulation promoter can be the only catalyst in forming the sol or can be used in addition to acid or basic catalyst. Additionally or alternatively, the coagulation promoter is added to a coagulation fluid to which shaped hydrolyzate is added.

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: A device for coagulating a warp of filaments from a linear spinneret by delivering a transparent, jetted sheet of coagulating liquid equally and uniformly along each side of the warp.

Abstract: A process for preparing aromatic polyamide film wherein an aromatic diamine and an aromatic diacidchloride are dissolved in an amide polymerization solvent containing an inorganic salt, a partial polymerization is effected at a low temperature to form an optically anisotropic liquid crystalline prepolymer dope, continuously extruding through a film die under a draw ratio or subjecting to a shear and contacting the prepolymer with a second solvent which is a polymerization accelerating-precipitation solvent to obtain an aromatic polyamide film free of crystal defect layer perpendicular to the film axis and having high strength and a high degree of molecular orientation.

Abstract: An apparatus for the production of a collagen tube to be used as a vascular prostheses or nerve suture, including a cylindrical tubular spinneret having a feed end for an aqueous solution of collagen gel and a discharge end and a coagulant tube concentrically disposed in the spinneret with all around circumferential clearance and terminating upstream of the discharge wherein a tube of aqueous acid collagen gel is extruded through the clearance around the coagulant tube. The coagulant tube has its inner wall contacted with a coagulating solution emerging therefrom before the tube of aqueous collagen gel reaches the discharge end of the cylindrical tubular spinneret. The discharge end of the tubular spinneret terminates in a bath of coagulating solution and a bed is disposed in the bath to receive the extruded collagen tube from the end of the tubular spinneret. The tubular spinneret is capable of being displaced with respect to the bath.

Abstract: A process for producing boron-containing ceramics such as boron carbide and boron nitride comprises pyrolyzing a blend of a precarbonaceous polymer such as polyacrylonitrile and a boron-containing polymer such as that formed by the reaction of a borane with a Lewis base. Pyrolyzation in an inert atmosphere yields boron carbide while pyrolyzation in a reactive gas burns away the precarbonaceous polymer and yiels a ceramic comprising the reaction product of boron and the pyrolyzation gas. Boron nitride ceramics are formed by pyrolyzing the preceramic blend in ammonia.

Abstract: Hydroxyethylated polybenzimidazole fibers are produced by a wet jet/wet spinning or by a dry jet/wet spinning process. A spinning solution of hydroxyethylated polybenzimidazole is extruded vertically downward through a spinneret into a liquid coagulation bath. The resulting fibers have pore sizes ranging from about 5 angstroms up to about 100 angstroms and are quite useful as ultra filters for molecules with a broad range of molecular weight.

Abstract: Boron ceramics including boron ceramic fibers are formed by pyrolyzing at temperatures greater than 800.degree. C. organoboron polymers which have been formed by condensing decaborane with amines or phosphines.

Abstract: The abrasion resistance and tensile strength of asbestos is significantly improved by the addition of significant amounts of metal oxides, such as iron oxide, under conditions to provide at least some surface bonding of the oxides to the surface of the asbestos. The oxides are preferably added during formation of bodies from asbestos dispersions and also impart color to the final product.

Abstract: Waste asbestos generated from a production process utilizing a surfactant as the dispersant and a coagulant as a solidifying agent is recovered for reprocessing by treating the waste with an inorganic acid to react with the precipitated surfactant and solubilize the precipitating ions. The precipitating ions are removed by washing. The insoluble residue, containing asbestos and the surfactant is mixed and reacted with an alkali to form a dispersion of asbestos that may be reprocessed by conventional methods.

Abstract: Coherent strands are made from a dispersion of asbestos fibres in an aqueous soap solution containing up to 100 percent molar excess of fatty acid, by a process including the steps of forming a stream of dispersion and chilling the newly formed stream sufficiently to gel the dispersion.

Abstract: Hollow cellulosic fibers are produced by nitrosating and dissolving a cellulosic material in an aprotic solvent selected from the group consisting of a dialkylacylamide and dimethylsulfoxide and regenerating the dissolved cellulose by contacting the cellulose solution with a regenerant. The regenerant is n-octanol where the solvent is a dialkylacylamide and n-hexanol where the solvent is dimethylsulfoxide. The fibers are hollow as regenerated and require no special spinnerette designs nor special spinning conditions.

Abstract: Regenerated cellulosic articles are produced by nitrosating and dissolving cellulose in a dialkylacylamide solvent, such as dimethylformamide, and regenerating the dissolved cellulose by passing into a coagulant bath. The coagulant comprises water or a 1 to 4 carbon atom aliphatic monohydric alcohol and a soluble reactive base, the latter in an amount ranging from 6% to 25% by weight of the regenerant. The process produces regenerated cellulose products of improved resistance to alkaline solubility.

Abstract: Shaped cellulosic fibers are produced by nitrosating and dissolving a cellulosic material in an aprotic solvent selected from the group consisting of a dialkylacylamide and dimethylsulfoxide and regenerating the dissolved cellulose by contacting the cellulose solution with a regenerant. The regenerant is butanol, pentanol or benzyl alcohol where the solvent is a dialkylacylamide and propanol, butanol or benzyl alcohol where the solvent is dimethylsulfoxide. The fibers have a generally crenulated shape as regenerated and require no special spinnerette designs nor special spinning conditions.

Abstract: A process for making a dispersion-based asbestos strand for later twisting to form a yarn comprises (a) forming an elongate continuous stream from an aqueous coagulable dispersion comprised of asbestos fibres, water and dispersion-forming chemicals; (b) coagulating said dispersion in said stream to form a self-sustaining asbestos fibre strand containing coagulated dispersion-forming chemicals together with uncoagulated residues thereof and water; (c) while said strand is in an untwisted state removing substantially the whole of the coagulated dispersion-forming chemicals and said uncoagulated residues thereof; and (d) adjusting the water content of the strand to provide an untwisted strand formed substantially wholly of said asbestos fibres and containing not more than 20% by weight of water.

Abstract: Creping of fibrous webs to enhance their softness and bulk is improved and the resulting creped web is made strong, water dispersible and non-blocking by employing a bonder and creping adhesive composition containing four components which are blended to produce a mixture having a percent solids of from 10% to 40% and an initial modulus for a film of the solids of less than 1.75 .times. 10.sup.8 dynes/cm.sup.2. The composition (mixture) functions as a bonder for the fibers to impart strength and as a creping adhesive for the web so that creping enhances softness and bulkiness. Also disclosed are methods of creping employing such a bonder and creping adhesive composition and sheet materials creped with such compositions.

Abstract: This invention relates to a process for the production of a shaped article of a plastic material of chemically modified protein, which comprises mixing an alkaline aqueous protein solution with an aqueous solution of an organic tetrafunctional, unsaturated compound of the general formula ##STR1## in which R.sub.1 and R.sub.2 are hydrogen or an alkyl group with 1 to 6 carbon atoms, andR.sub.3 is the group --(CH.sub.2).sub.n --, n being an integer from 1 to 8, or the group ##STR2## in which R.sub.4 is an alkyl group with 1 to 18 carbon atoms, SPINNING THE RESULTING VISCOUS LIQUID READY FOR SPINNING BY MEANS OF A SHAPING DIE INTO A PRECIPITATING LIQUID, WASHING THE SHAPED ARTICLE WITH A WASHING LIQUID, CAUSING AN AQUEOUS SOLUTION OF AN ORGANIC, SATURATED, AT LEAST BIFUNCTIONAL COMPOUND TO ACT ON THE ARTICLE, HEATING THE ARTICLE, OPTIONALLY CAUSING PLASTICIZER LIQUID TO ACT ON IT, AND DRYING.

Abstract: A wet process for producing continuous strands from discontinuous inorganic fibers by extruding and aligning a dispersion of said fibers in a liquid medium, which medium contains a gelable agent, into a coagulating bath to gel and convert the agent to a binder for the fibers until they are mechanically interlocked, and subsequently removing the binder. A fibrous strand produced in accordance with the process, with and without the binder included.

Abstract: A process for preparing hydrophilic cross-linked polymers and products prepared thereby, said process comprising admixing in a solvent-free system in the presence of a free radical, vinyl polymerization catalyst and reacting a major amount of a water-soluble polymerizable monoester of an olefinic acid having at least one substituted functional group with a minor amount of a polymerizable diester of one of said olefinic acids having at least two esterifiable hydroxyl groups. The novel products include a solid friable foam which can be disintegrated to powder. Shaped bodies can be prepared in the form of articles which can be cast with additives such as fragrances, medicinals, flavors, chemicals and the like, which are gradually released from the article when it is wetted in water or alcohol. Liquid casting syrups adapted to be polymerized in situ with or without additives can be formed.