Abstract: Ibuprofen is isolated from tablets or other solids by dissolving the ibuprofen in an alkane or cycloalkane solvent, filtering off undissolved solid, and stripping the solvent from the ibuprofen by evaporation or by recrystallization at low temperatures.

Abstract: 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.

Abstract: A process for enhancing the thermo-oxidation stability of a polybenzimidazole-containing article wherein the article contains from about 5 to about 100 weight percent of polybenzimidazole and from about 0 to about 95 weight percent of a thermoplastic polymer, by the steps of providing a phosphoric acid solution of about 2.0 to about 10.0 weight percent of acid; contacting the polybenzimidazole-containing article with the acid solution for sufficient time to produce an acid-treated article; drying the acid-treated article at a low temperature to remove excess acid; and heat treating the dried article at a temperature ranging from about 400.degree. to about 500.degree. C. in an inert atmosphere to form a phosphate barrier layer on the surface of the article, wherein the article retains at least about 50 percent of its weight after isothermal aging at about 600.degree. F. for a period of at least about 300 hours.

Abstract: 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.

Abstract: A coextruded liquid crystal polymer ("LCP") film or sheet wherein a higher melting LCP layer is laminated to a lower melting LCP layer. These LCP components are coextruded from the same die. This film or sheet may then be laminated onto other materials at a temperature between the melting point of the lower-melting LCP and the higher-melting LCP, so that the latter LCP may maintain its shape, orientation, and mechanical characteristics while the lower-melting LCP component flows and bonds with the other material. When the higher-melting LCP layer is sandwiched between two lower-melting layers, the film or sheet may be laminated on two sides thereof.

Abstract: A cold compactible polymeric powder capable of being compressed into a shaped article includes a polybenzimidazole containing powder having an apparent density ranging from about 0.14 to about 0.300 gm/cm.sup.3, a compaction constant ranging from about 0.100 to about 0.500 MPa.sup.-1, and a plasticizer content ranging from about 1 to about 25 weight percent The highly porous polymeric powders are preferably formed by dissolving polymeric resins in a suitable solvent to form a polymeric solution, and atomizing the solution into a droplet atmosphere of a non-solvent.

Abstract: A process for making filled molding powders by preparing a dilute solution of a polymer, making a slurry of a filler in the polymer solution, and then causing the polymer to come out of solution, e.g. by adding a nonsolvent or by solvent evaporation, so that the polymer coats the filler particles.

Abstract: A moldable thermoset composition comprising about 5-60% liquid crystal polymer and about 95-40% of an epoxy-functional rubber by weight, a process for making and a process for using same. The composition is made by melt mixing the LCP and the epoxy-rubber to form a blend. This blend is then cooled and may be molded, extruded, or otherwise formed into a desired shape. The composition is then heat-treated to make it set.

Abstract: 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.

Abstract: A flexible foamed liquid crystal polymer film or sheet having uniformly small cells or bubbles. The foam cells are essentially spherical and have mean diameters less than or equal to approximately 250 microns. The cell size distribution is relatively small. The foamed sheet is made by extruding the polymer through a die under pressure at a temperature near or below the polymer's melting point; a gas or chemical blowing agent is extruded with the polymer to produce foaming as the polymer exits the die.

Abstract: 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.

Abstract: Polymer compositions are provided which are capable of being formed into shaped articles and comprise a poly(2-methylpentamethylene terephthalamide), also known as nylon M5T, and a minor amount of an ionomer, e.g., a partially neutralized copolymer of an alpha-olefin and an alpha, beta-ethylenically unsaturated carboxylic acid. In particular, the compositions may be melt spun and drawn into filaments having good mechanical properties.

Abstract: A graft copolymer having a polyolefinic main chain with muconic acid groups pendant therefrom. The acid groups are bonded to the backbone of the polyolefin by free radical addition across a muconic acid double bond. Preferably, the copolymer is prepared via a reactive extrusion process. The copolymer's applications include use as a reactive compatibilizer for polymer blends. The preferred polyolefin is polypropylene.

Abstract: The present invention discloses a wholly aromatic, melt processable polyester which is comprised of recurring moieties derived from the following compounds: 2,6-naphthalenedicarboxylic acid, 4-hydroxybenzoic acid, an aromatic dihydroxy compound, and 6-hydroxy-2-naphthoic acid. The resulting wholly aromatic polyester is capable of forming a thermotropic melt phase at temperatures below approximately 350.degree. C. and most preferably at temperatures below approximately 290.degree. C.

Abstract: A process for preparing polyarylates having low color wherein isophthalic acid, terephthalic acid, and bisphenol A are melt polymerized to form a prepolymer, the prepolymer is crystallized, and then further polymerized in the solid state by heating under an inert gas flow, e.g. nitrogen. Crystallization is accomplished by adding the amorphous prepolymer in powder or pellet form to a organic crystallizing medium such as 2-ethoxyethyl acetate or hexyl acetate. This process produces a polymer having low color content. The crystallized polymer may be made amorphous by melting. This amorphous polymer is useful in applications requiring a transparent, colorless plastic.

Abstract: Novel polyimide blends are formed of polyimide polymers each having moieties derived from dianhydride and diamine comonomers. The miscible blends of the present invention may be formed by selecting polyimide polymers having structurally different dianhydride-derived moieties, as well as structurally different diamine-derived moieties. More specifically, the blends of this invention include at least one polyimide polymer which is a reaction product of 2,2-bis(3,4-dicarboxyphenyl) hexafluoropropane dianhydride, and 2,2-bis(3-aminophenyl) hexafluoropropane; and at least another polyimide polymer which is a reaction product of 2,2-bis(4-aminophenyl) hexafluoropropane and a dianhydride which is at least one selected from the group consisting of pyromellitic dianhydride, bis(3,4-dicarboxyphenyl) ether dianhydride, and 3,3',4,4'-benzophenone tetracarboxylic dianhydride.

Abstract: Novel polyimide blends are formed of polyimide polymers each having moieties derived from dianhydride and diamine comonomers. The blends of the present invention may be formed by selecting polyimide polymers having structurally identical dianhydride-derived moieties, but structurally different diamine-derived moieties. Preferred miscible blends are formed wherein one of polyimides in the blend is the polymer condensation product of a dianhydride selected from 2,2-bis(3,4-dicarboxyphenyl) hexafluoropropane dianhydride, 3,3',4,4'-diphenyl tetracarboxylic dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, bis(3,4-dicarboxyphenyl ether dianhydride, pyromellitic dianhydride, and mixtures thereof, and 2,2-bis(3-aminophenyl) hexafluoropropane, and another of the polyimides in the blend is the polymer condensation product of the same dianhydride and mixtures thereof noted above, and 2,2-bis(4-aminophenyl) hexafluoropropane.

Abstract: A process for converting 1,4-butanediol to tetrahydrofuran using polybenzimidazole to catalyze the reaction. The conversion is accomplished by heating the 1,4-butanediol in the presence of the PBI. The THF product may be distilled from the reaction solution as an azeotrope with water. To function as the catalyst, the PBI must first be pre-treated with a strong aqueous acid such as sulfuric acid. The catalyst may be in the form of microporous resin beads, hollow fibers, or other forms of PBI. This process exhibits a high selectivity for producing THF without side reactions.

Abstract: A method is provided for producing a corrosion resistant metallic article. The article to be protected is coated with a solution containing a polymeric composition drawn from the class of polymers commonly known as polybenzimidazoles, followed by drying or curing of the coated article. The coated metallic article resists corrosion under severe conditions. The coating adheres well, being non-peeling and resistant to organic solvents and heat.

Abstract: An improved method of gas separation and novel polyimide membranes are disclosed and claimed. Membranes in accordance with the present invention include the condensation product of fluorinated diamines such as 2,2'-bis(3-aminophenyl)hexafluoropropane, 2,2'-bis(4-aminophenyl)hexafluoropropane and 2-(3-aminophenyl)-2'-(4-aminophenyl)hexafluoropropane with aromatic dianhydrides such as 3,3', 4,4' benzophenone tetracarboxylic acid dianhydride.