Abstract: Anisotropic gas separation membranes are treated to alter the microporosity of their thin, dense layer or composite coating--the layer or coating which provides selectivity in separations employing such membranes. The treatment increases the selectivity of a membrane with minimal decrease in its flux. The process comprises applying a polar activator to the membrane followed by exposing the membrane to microwave frequency radiation for a period of time sufficient to compact the thin layer of the membrane. The polar activator may be incorporated in the membrane during fabrication or applied as an after-treatment.

Abstract: The invention provides a denture liner composition for a composite denture based on a phosphonitrilic fluoroelastomer [poly(fluoroalkoxy)phosphazene] curable at atmospheric pressure at temperatures of about 100.degree. C. or less, conveniently by immersing the packed denture flask in a water bath at the appropriate temperature. The composition includes trimethacrylate and dimethacrylate cross-linking agents for increasing liner hardness and decreasing water sorption characteristics of the cured liner. The composition preferably further includes filler materials for increasing the hardness of the liner product. The composite denture is preferably prepared in a one-step process wherein the liner composition material of a single firmness is cured in situ with the denture base material.

Abstract: The invention provides a denture liner composition for a composite denture based on a phosphonitrilic fluoroelastomer (poly(fluoroalkoxy)phosphazene) curable at atmospheric pressure at temperatures of 100.degree. C. or less, conveniently by immersing the packed denture flask in a water bath at the appropriate temperature. The composition includes filler materials for increasing the hardness of the cured liner, interpenetrating polymers for increasing firmness and bond strength, and cross-linking agents for increasing the tensile strength and bond strength of the cured liner. The composite denture is preferably prepared in a one-step process wherein the liner composition material of a single firmness is cured in situ with the denture base material.

Abstract: The invention provides a denture liner composition for a composite denture based on a phosphonitrilic fluoroelastomer (poly(fluoroalkoxy)phosphazene) curable at atmospheric pressure at temperatures of 100.degree. C. or less, conveniently by immersing the packed denture flask in a water bath at the appropriate temperature. The composition includes filler materials for increasing the hardness of the cured liner, interpenetrating polymers for increasing firmness and bond strength, and cross-linking agents for increasing the tensile strength and bond strength of the cured liner. The composite denture is preferably prepared in a one-step process wherein the liner composition material of a single firmness is cured in situ with the denture base material.

Abstract: A prosthetic denture which is lined on its tissue bearing surfaces with a phosphonitrilic fluoroelastomer layer to provide a resilient, durable cushion for the prosthetic denture; and a method for making same is disclosed.

Abstract: Hollow synthetic fibers useful in reverse osmosis, ultrafiltration, gas separation and the like, having high hydraulic permeability to the solvent and capable of operation at pressures from 600 psi and up, are prepared by forming a solution of a fiber-forming polymer in a suitable solvent, adding to the solution a second polymer soluble in the solvent but with limited compatibility with the first polymer when their total concentration increases on coagulation, extruding the resulting solution through an orifice equipped for coaxial extrusion so that coagulating fluid within tube flow results, precipitating with a liquid which is miscible with the solvent for the fiber-forming material, is a non-solvent for the first polymer and a solvent for the second, contacting the extruded solution with the precipitating liquid either coaxially through the extrusion device or by passing the extrudate through the precipitating liquid, and finally washing the resulting hollow fiber free of residual solvents and non-solvents