Abstract: The invention relates to a novel process for depolymerizing polyesters by subjecting the polyesters to catalysts and organic solvents which are substantially free of oxygen and water in order to produce macrocyclic polyester oligomers substantially free of hydroxybutyl terminated linear impurities.

Abstract: A carbonate ester is produced by the metal-induced reaction of a hydroxy compound with a sulfur compound in a melt process. An orthocarbonate can also be produced. The orthocarbonate can be converted into carbonate ester in a subsequent operation.

Abstract: Aromatic polyether polymers, illustrated by polyethersulfones, polyetherketones and polyetherimides, are prepared by a phase transfer catalyzed reaction between a hydrate of a salt of a dihydroxyaromatic compound and a substituted aromatic compound such as bis(4-hydroxyphenyl) sulfone, bis(4-hydroxyphenyl) ketone or 1,3-bis[N-(4-chlorophthalimido)]benzene. Isolation of the hydrate and its conversion to the anhydrous salt prior to the polymerization reaction affords a polymer of higher molecular weight than other methods of preparing the anhydrous salt.

Abstract: A method for preparing rapidly crystallized polyesters from macrocyclic polyester oligomers comprising the step of contacting macrocyclic polyester oligomers, polymerization catalysts and nucleating agents.

Abstract: A method for protecting thermal barrier coatings deposited on engine parts from the deleterious effects of environmental contaminants at high temperatures is given. The method uses a sacrificially consumed oxide coating with the thermal barrier coating, where the consumption of the oxide coating increases the melting temperature of a contaminant composition above the surface temperature of the thermal barrier coating, or increases the viscosity of the contaminant composition to prevent its infiltration into the thermal barrier coating.

Abstract: Macrocyclic polyester oligomer compositions are polymerized to high molecular weight polyesters by heating with a titanate ester composition comprising moieties having oxygen or nitrogen chelated with a titanium atom or having two titanium atom connected by alkylene ester units. Depending on the chemical nature of the initiator, the polymerization reaction may be extremely rapid as desired for structural reaction injection molding, or may have an induction period as desired for resin transfer molding.

Abstract: A process for fabricating a fully dense ceramic preform for a piezoelectric or electrostrictive composite exhibiting anisotropic 3--3 connectivity. The process involves preparing a homogeneous slurry of a piezoelectric ceramic powder, a binder, dispersant, and a liquid medium. The slurry is freeze dried to form a ceramic preform having ceramic interconnected lamelli having greater connectivity in the Z direction than in the X and Y direction, and having interconnected interlamellar regions. The composite is fabricated by infiltrating the fully dense ceramic preform with an infiltrate phase in the interconnected interlamellar regions. The composite may be poled to produce a piezoelectric composite for electromechanical devices exhibiting anisotropic 3-3 connectivity.

Abstract: A method for making polyarylene ethers comprising the step of melt polymerizing 2,6-disubstituted-4-alkylphenols in the presence of an oxidative coupling catalyst and in the absence of environmentally unfriendly solvents.

Abstract: Close-coupled atomization methods employing non-axisymmetric fluid flow geometries have demonstrated superior efficiency in the production of fine superalloy powder, such as, for example, nickel base superalloys compared to conventional close-coupled atomization utilizing an axisymmetric gas orifice and an axisymmetric melt nozzle. It is believed that the principal physical mechanisms leading to non-axisymmetric atomization system fine powder yield improvement are atomization plume spreading, the at least lessening of the melt pinch down at the interaction point between the atomization liquid and the liquid melt and improved melt film formation at the melt guide tube tip. The greatest fine powder yield improvement occurred when the non-axisymmetric atomization systems are operated with atomization parameters that result in the formation of multiple atomization plumes.

Abstract: A superconductive article is made from interwoven superconductive, metallic tapes. The interwoven tapes are electrically interconnected by a plurality of superconductive interconnections that extend between the interwoven tapes. Articles of the invention may be formed from tapes comprising superconductive Nb.sub.3 Sn having Nb.sub.3 Sn interconnections.

Abstract: An improved high performance x-ray system having a rotating anode therein which includes an improved target/stem assembly comprising a metallic target and a large bore, thin-walled tubular metal stem which, when connected to a rotor body assembly, provides a rotating x-ray tube anode assembly is disclosed. An insert of an alloy, for example, tantalum alloy, is placed between the target layer and the large bore, thin-walled tubular niobium or niobium alloy stem and then bonded thereto to produce a composite x-ray tube target/stem assembly. The target/stem assembly is then connected to a rotor body assembly by fasteners, preferably threaded, to produce a rotating anode assembly having high bond strength that provides acceptable balance during x-ray tube operations.

Abstract: Polyestercarbonates, particularly those containing aliphatic dicarboxylic acid-derived structural units, are redistributed by heating in the presence of a carbonate redistribution catalyst, and, optionally, a diaryl carbonate. The redistribution products have weight average molecular weights different from, and typically lower than, the initial molecular weight.

Abstract: Inorganic powder, preferably fumed silica, is rendered hydrophobic by treatment with a silylating agent in the presence of a third reagent selected from the group consisting of protonic acids, especially those having a boiling point at atmospheric pressure up to 120.degree. C., preferably formic acid, and linear phosphonitrilic halides, preferably linear phosphonitrilic chlorides.

Abstract: A method of electroslag refining of metal is taught. The method includes the introduction of unrefined metal into an electroslag refining process in which the unrefined metal is first melted at the upper surface of the refining slag. The molten metal is refined as it passes through the molten slag. The refined metal is collected in a cold hearth apparatus having a skull of refined metal formed on the surface of the cold hearth for protecting the cold hearth from the leaching action of the refined molten metal. A cold finger bottom pour spout is formed at the bottom of the cold hearth to permit dispensing of molten refined metal from the cold hearth.

Abstract: Polycarbonate compositions are redistributed by melt equilibration using diethyldimethylammonium hydroxide as the redistribution catalyst. This catalyst affords an odorless polycarbonate product having a very low residual amine level.

Abstract: An apparatus and a method provide for the extruding of thermoplastic insulation onto complex shapes, such as generator stator bars. The method of the present invention comprises the steps of feeding the complex shape through a central bore of an extrusion die to deposit a thermoplastic coating along the entire length of the shape as the extrusion die traverses the length of the complex shape.

Abstract: Insulating foam for refrigerators and the like is prepared by blowing in the presence of carbon dioxide as the sole or principal blowing agent. The thermal conductivity of the foam is decreased by sealing said foam in a gas-impervious enclosure with at least one getter, such as an alkaline material, capable of removing carbon dioxide and at least one drying agent which will produce a relative humidity greater than the equilibrium relative humidity over a saturated aqueous solution of the getter, thus removing water without rendering the getter anhydrous. For example, calcium chloride dihydrate may be used when the getter is sodium hydroxide.

Abstract: A method for the recycling of overspray powder during spray forming is provided. The method involves providing a refining vessel to contain an electroslag refining layer floating on a layer of molten refined metal. An ingot of unrefined metal is lowered into the vessel into contact with the molten electroslag layer. A current is passed through the slag layer to the ingot to cause surface melting at the interface between the ingot and the electroslag layer. As the ingot is surface melted at its point of contact with the slag, droplets of the unrefined metal are formed and these droplets pass down through the slag and are collected in a body of molten refined metal beneath the slag. The refined metal is held within a cold hearth. At the bottom of the cold hearth, a cold finger orifice permits the withdrawal of refined metal from the cold hearth apparatus. The refined metal passes from the cold finger orifice as a stream.

Abstract: A process for making high ductile and high melting point polyesters comprising the step of contacting macrocyclic copolyester oligomers having structural units with C.sub.4 alkylene bridging radicals and structural units with bridging radicals other than C.sub.4 alkylenes, and a polymerization catalysts.

Abstract: A method of high retained strain forging is described for Ni-base superalloys, particularly those which comprise a mixture of .gamma. and .gamma.' phases, and most particularly those which contain at least about 30 percent by volume of .gamma.'. The method utilizes an extended subsolvus anneal to recrystallize essentially all of the superalloy and form a uniform, free grain size. Such alloys may also be given a supersolvus anneal to coarsen the grain size and redistribute the .gamma.'. The method permits the manufacture of forged articles having a fine grain size in the range of about ASTM 5-12 (5-60 .mu.m).