Abstract: A method of separating a polymer-solvent mixture is described wherein a polymer-solvent mixture is heated prior to its introduction into an extruder comprising an upstream vent and/or a side feeder vent to allow flash evaporation of the solvent, and downstream vents for removal of remaining solvent. The one-step method is highly efficient having very high throughput rates while at the same time providing a polymer product containing low levels of residual solvent.

Abstract: A method of separating a polymer-solvent mixture is described wherein a polymer-solvent mixture is heated prior to its introduction into an extruder comprising an upstream vent and/or a side feeder vent to allow flash evaporation of the solvent, and downstream vents for removal of remaining solvent. The one-step method is highly efficient having very high throughput rates while at the same time providing a polymer product containing low levels of residual solvent.

Abstract: Polyether polymers, such as polyetherimides, are prepared by the reaction of a dihydroxy-substituted aromatic hydrocarbon alkali metal salt, such as bisphenol A disodium salt, with a bis(N-(chlorophthalimido))aromatic compound, such as 1,3- and/or 1,4-bis[N-(4-chlorophthalimido)]benzene, in a solvent such as o-dichlorobenzene and in the presence of a phase transfer catalyst such as a hexaalkylguanidinium chloride. Several embodiments may be employed to improve the method. They comprise employing substantially dry reagents, employing a high solids level in solvent, beginning with an excess of bis(N-(chlorophthalimido))-aromatic compound and incrementally adding alkali metal salt, employing alkali metal salt of small particle size, and using reagents of high purity.

Abstract: A method of separating a polymer-solvent mixture is described wherein a polymer-solvent mixture is heated prior to its introduction into an extruder comprising an upstream vent and/or a side feeder vent to allow flash evaporation of the solvent, and downstream vents for removal of remaining solvent. The one-step method is highly efficient having very high throughput rates while at the same time providing a polymer product containing low levels of residual solvent.

Abstract: Disclosed is a method for preparing an alkali metal salt of a hydroxy-substituted hydrocarbon which comprises the steps of (i) contacting in solvent media at least one hydroxy-substituted hydrocarbon with a base comprising an alkali metal cation; and (ii) devolatilizing the solvent media comprising alkali metal salt by adding or spraying the solvent media into a substantially water-immiscible organic solvent, said solvent being at a temperature greater than the boiling point of solvent media at the prevailing pressure. In one embodiment the solvent media comprises water, and optionally at least one water-soluble protic organic solvent.

Abstract: Fine-grained and/or equiaxed coatings, substantially free from columnar structure, are deposited on substrates by chemical vapor deposition by directing the flow of reactant gases to the substrate with high velocity and in close proximity thereto, most often at a velocity gradient of at least about 1050 and preferably at least about 2000 cm./cm.-sec. The deposition process is preferably conducted while moving the substrate so as to coat large areas thereof. By this method, tungsten and/or rhenium X-ray targets having excellent properties under conditions of rapid temperature cycling may be produced.