Abstract: A method and apparatus for incorporating an additive material into a fibrous web to be bonded into an elongated porous element by heating the fibers in a confined forming die with a heating medium adapted to bond the fibers to each other at spaced points of contact. An additive material is admixed with the heating medium and then the web of fibers is contacted with the heating medium/additive material mixture whereby the heating medium simultaneously carries the additive material into the fibrous web and heats the fibers to bond them into the porous element. The apparatus includes an adjustable venturi assembly through which the heating medium passes to create a pressure gradient adapted to aspirate a quantity of additive material and entrain a metered quantity of same in the heating medium.

Abstract: Melt blown bicomponent fibers comprising a sheath of polyethylene terephthalate or a copolymer thereof and a core of nylon 6,6 and a reservoir or a nib in a writing or marking instrument comprising a porous element formed from such fibers bonded to each other at spaced points of contact. For use as a nib the core polymer may also be polybutylene terephthalate.

Abstract: Disclosed herein is a medium for analyzing a substance in a mixture and method of making and using. In particular, the medium comprises a network of at least one polymeric fiber having a derivatized polymeric surface which allows immobilization of at least one selective binding agent thereon in a highly dispersed and randomly spaced orientation which forms a tortuous interstitial path for passage of the mixture therethrough. The substance may be a chemical substance or a biological substance. Also disclosed are assay matrices, assay systems and kits comprising the medium.

Abstract: Processes for recovering 4,4'-dimethyl bibenzoate (DMBB) from byproduct streams of dimethyl terephthalate (DMT) production are disclosed. The byproduct streams are treated to produce an overhead stream which includes DMBB. In one aspect of the invention, the overhead product stream is added to an organic solvent under conditions sufficient to rapidly form a suspension of crystallized DMBB. In another aspect of the invention, the overhead is dissolved in an appropriate organic solvent and cooled to form a suspension of DMBB crystals in the solvent. A portion of the suspension is removed, and the remaining portion of the suspension centrifuged to recover DMBB crystals. In still another aspect of the invention, the overhead stream is treated with an organic solvent to form a slurry of DMBB crystals, and the resultant slurry thermally treated to increase the concentration of DMBB crystals therein while also solubilizing any organic contaminants.

Abstract: Molded article having improved thermal resistance and strength formed from a homogeneous mixture comprising from about 5 to 75 percent by weight polybenzimidazole and from about 95 to 25 percent by weight of a polyaryleneketone. These articles are obtained by injection molding techniques.

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: Molded article having improved thermal resistance and strength formed from a homogeneous mixture comprising from about 5 to 75 percent by weight polybenzimidazole and from about 95 to 25 percent by weight of a polyaryleneketone. These articles are obtained by injection molding techniques.

Abstract: A method is provided for the production of 3,3', 4,4'-tetraaminobiphenyl (TAB) from biphenyl comprising the following steps:1) acetylating the biphenyl in the presence of an appropriate Friedel-Crafts catalyst to obtain 4,4'-diacetylbiphenyl (DAcB);2) oximating the DAcB to form DAcB dioxime;3) subjecting the dioxime to a double Beckmann rearrangement to obtain N,N-diacetylbenzidine (DiAcBz);4) nitrating the DiAcBz to obtain 3,3'-dinitro-N,N-diacetylbenzidine (DNAcBz)5) removing the acetyl groups of the DNAcBz by basic hydrolysis to form 3,3'-dinitrobenzidine (DNB); and6) reducing the nitrate groups of the DNB to form TAB.

Abstract: Sinterd molded article having improved thermal resistance and strength formed from a homogeneous mixture comprising from about 5 to 75 percent by weight polybenzimidazole and from about 95 to 25 percent by weight of a polyaryleneketone.

Abstract: Sintered polybenzimidazole articles are obtained by compacting a particulate, dried polybenzimidazole resin under a pressure of 2,000 to 10,000 psi in a mold, heating the formed article to a temperature in the range of 825.degree. to 950.degree. F. for at least four hours, cooling the polybenzimidazole article to below 800.degree. F. while maintaining the article under a pressure of 2,000 to 10,000 psi, and thereafter heating the constrained formed polybenzimidazole article to a temperature in the range of 825.degree. to 950.degree. F. for at least one hour.

Abstract: Sintered polybenzimidazole articles are obtained by compacting a particulate, dried polybenzimidazole resin under a pressure of 2,000 to 10,000 psi in a mold, heating the formed article to a temperature in the range of 825.degree. to 950.degree. F. for at least four hours, cooling the polybenzimidazole article to below 800.degree. F. while maintaining the article under a pressure of 2,000 to 10,000 psi, and thereafter heating the constrained formed polybenzimidazole article to a temperature in the range of 825.degree. to 950.degree. F. for at least one hour.

Abstract: A two stage process for the production of benzimidazole/aromatic amide polymers and copolymers and wholly aromatic polyamides is provided wherein an aromatic amine component comprising an aromatic diamine or triamine and optionally, an aromatic tetraamine is reacted with an aromatic dicarboxylic acid and/or ester. The reactants are heated with agitation in a first stage to a temperature at least sufficient to initiate condensate evolution. The agitation is then discontinued and the reaction is allowed to proceed, in many cases with the formation of a foam while heating is continued. The reaction mass is then allowed to solidify by cooling and is crushed to a ground prepolymer which is heated with agitation in a second stage to a temperature higher than that of the first stage until the desired polymer is obtained. The invention also includes certain benzimidazole/aromatic amide polymers and copolymers as new compositions of matter.

Abstract: A two stage process for the production of polybenzimidazoles is provided wherein an aromatic tetraamine, e.g., 3,3',4,4'-tetraaminobiphenyl, is reacted with a dicarboxylic component consisting of at least one compound having the formula: ##STR1## in which R' is a divalent organic radical and may be the same or different in the various molecules making up the dicarboxylic component and the Y's may be the hydrogen, aryl or alkyl, with no more than 95% the Y's being hydrogen or phenyl. The reactants are heated with agitation in a first stage to a temperature above the melting point of the tetraamine until the viscosity of the mixture rises as indicated by an agitator torque of at least 1.5 times that before the rise in viscosity. The agitation is then discontinued and the reaction mixture is allowed to foam while heating is continued. The foam is then allowed to cool to a friable mass and is crushed to a ground prepolymer which is heated with agitation in a second stage until the desired polymer is obtained.

Abstract: A two stage process for the production of polybenzimidazoles and a novel polybenzimidazole produced there by is provided wherein a mixture of an aromatic tetraamine, e.g., 3,3',4,4'-tetraaminobiphenyl and a free dicarboxylic acid, e.g., isophthalic acid, is heated with agitation in a first stage to a temperature above the melting point of the tetraamine until the viscosity of the mixture rises as indicated by an agitator torque of at least 1.5 times that before the rise in viscosity. The agitation is then discontinued and the reaction mixture is allowed to foam while heating is continued. The foam is then allowed to cool to a friable mass and is crushed to a ground prepolymer which is heated with agitation in a second stage until the desired polymer is obtained. The novel polybenzimidazole produced is the reaction product of phenylindandicarboxylic acid and 3,3',4,4'-tetraaminobiphenyl.

Abstract: This invention provides a two stage melt polymerization process for the production of an improved type of high molecular weight polybenzimidazole, which involves the use of an arylphosphine or arylphosphite polymerization catalyst.The process provides poly-2,2'-(m-phenylene)-5,5'-bibenzimidazole of improved color and Plugging Value, and is further characterized by an inherent viscosity of at least about 0.9 dl/g, and a weight average molecular weight of at least about 140,000.

Abstract: This invention provides a two stage melt polymerization process for the production of an improved type of high molecular weight polybenzimidazole, which involves the use of an arylphosphine or arylphosphite polymerization catalyst.The process provides poly-2,2'-(m-phenylene)-5-5'-bibenzimidazole of improved color and Plugging Value, and is further characterized by an inherent viscosity of at least about 0.9 dl/g, and a weight average molecular weight of at least about 140,000.