Abstract: Separation of the components of liquid mixtures is achieved by contacting a liquid mixture with a nonporous membrane having a fluoropolymer selectively permeable layer and imposing a pressure gradient across the membrane from feed side to permeate side. Unusually high transmembrane flux is obtained when the membrane is subjected to one or more process conditions prior to separation. These include (a) leaving some residual amount of membrane casting solvent in the membrane, and (b) contacting the membrane with a component of the mixture to be separated for a duration effective to saturate the membrane with the component.

Abstract: A method of removing water from fluid mixtures of the water with other compounds uses selective vapor permeation or pervaporation of the water, as the case may be, from the mixture through a membrane having an amorphous perfluoropolymer selectively permeable layer. The novel process can be applied in such exemplary embodiments as (a) removing water from mixtures of compounds that have relative volatility of about 1-1.1 or that form azeotropic mixtures with water, (b) the dehydration of hydrocarbon oil such as hydraulic fluid to concentrations of water less than about 50 ppm, (c) removing water byproduct of reversible chemical equilibrium reactions to favor high conversion of reactants to desirable products, (d) drying ethanol to less than 0.5 wt. % water as can be used in fuel for internal combustion engines, and (e) controlling the water content to optimum concentration in enzyme-catalyzed chemical reactions carried out in organic media.

Abstract: A method of removing water from fluid mixtures of the water with other compounds uses selective vapor permeation or pervaporation of the water, as the case may be, from the mixture through a membrane having an amorphous perfluoropolymer selectively permeable layer. The novel process can be applied in such exemplary embodiments as (a) removing water from mixtures of compounds that have relative volatility of about 1-1.1 or that form azeotropic mixtures with water, (b) the dehydration of hydrocarbon oil such as hydraulic fluid to concentrations of water less than about 50 ppm, (c) removing water byproduct of reversible chemical equilibrium reactions to favor high conversion of reactants to desirable products, (d) drying ethanol to less than 0.5 wt. % water as can be used in fuel for internal combustion engines, and (e) controlling the water content to optimum concentration in enzyme-catalyzed chemical reactions carried out in organic media.

Abstract: A method of removing water and/or methanol from fluid mixtures of the water or methanol with other compounds uses vapor permeation or pervaporation of the water or methanol, as the case may be, from the mixture through a membrane having an amorphous perfluoropolymer selectively permeable layer. The novel process can be applied in such exemplary embodiments as (a) removing water or methanol from mixtures of compounds that have relative volatility of about 1-1.1 or that form azeotropic mixtures with water or methanol, (b) the dehydration of hydrocarbon oil such as hydraulic fluid to concentrations of water less than about 50 ppm, (c) removing water and methanol byproducts of reversible chemical reactions thereby shifting equilibrium to favor high conversion of reactants to desirable products, (d) drying ethanol to less than 0.5 wt.

Abstract: Separation of the components of liquid mixtures is achieved by contacting a liquid mixture with a nonporous membrane having a fluoropolymer selectively permeable layer and imposing a pressure gradient across the membrane from feed side to permeate side. Unusually high transmembrane flux is obtained when the membrane is subjected to one or more process conditions prior to separation. These include (a) leaving some residual amount of membrane casting solvent in the membrane, and (b) contacting the membrane with a component of the mixture to be separated for a duration effective to saturate the membrane with the component.

Abstract: A method of separating components of mixtures of chemical compounds uses a nonporous membrane of copolymer of a perfluorinated cyclic or cyclizable monomer, and a 4 carbon dicarboxyl-containing comonomer, such as maleic anhydride. Optionally, the membrane composition includes an acyclic fluorinated olefin termonomer. The membranes provide a remarkably high selectivity of water relative to organic solvents and inorganic acids compared to dipolymer membranes of perfluorinated comonomers.

Abstract: A cyclic process for controlling environmental emissions of volatile organic compounds (VOC) from vapor recovery in storage and dispensing operations of liquids maintains a vacuum in the storage tank ullage. In the first part of a two-part cyclic process ullage vapor is discharged through a vapor recovery system in which VOC are stripped from vented gas with a selectively gas permeable membrane. In the second part, the membrane is inoperative while gas pressure rises in the ullage. In one aspect of this invention, a vacuum is drawn in the membrane separation unit thus reducing overall VOC emissions.

Abstract: Homogeneous, particulate composites are provided, of about 75-99.5 weight percent ultrahigh molecular weight polyethylene (UHMWPE) and about 0.5-25 weight percent of at least one filler compound, and wherein the composites have a surface area of at least about 4 m.sup.2 /g. The particulate UHMWPE is also provided without the filler. Dense, load-bearing articles of these materials are formed by cold-pressing and free-sintering procedures. Cold-pressable, free-sinterable blends of commercial UHMWPE containing at least 25 weight percent of the composites or unfilled UHMWPE of the invention are also provided.

Abstract: An air intake system for a mobile combustion engine is disclosed. The air intake system comprises a membrane formed from an amorphous polymer of perfluoro-2,2-dimethyl-1,3-dioxole, the membrane exhibiting an oxygen-nitrogen selectivity of at least 1.4:1. Either the permeate section or the feed section of the membrane is adapted to be in fluid flow communication with a combustion zone of the mobile combustion engine. The membrane preferably has an oxygen flus in excess of 100 Barrers, especially in excess of 500 Barrers. The air intake system provides either oxygen-enriched air or oxygen-deplected air for the engine, depending on the mode of operation of the engine.

Abstract: An air intake system for a residential combustion furnace is disclosed. The air intake system comprises a membrane formed from an amorphous polymer of perfluoro-2,2-dimethyl-1,3-dioxole, the membrane exhibiting an oxygen/nitrogen selectivity of at least 1.4:1. The permeate section of the membrane is adapted to be in fluid flow communication with a combustion zone of the residential combustion furnace. The membrane preferably has an oxygen flux in excess of 100 Barrers, especially in excess of 500 Barrers. The air intake system provides oxygen-enriched air for the furnace, to make the furnace more efficient.

Abstract: An air intake system for a mobile combustion engine is disclosed. The air intake system comprises a membrane formed from an amorphous polymer of perfluoro-2,2-dimethyl-1,3-dioxole, the membrane exhibitign an oxygen/nitrogen selectivity of at least 1.4:1. The permeate section of the membrane is adapted to be in fluid flow communication with a combustion zone of the mobile combustion engine. The membrane preferably has an oxygen flux in excess of 100 Barrers, esepcially in excess of 500 Barrers. The air intake system provides oxygen-enriched air for the engine, to make the engine more efficient.

Abstract: A selectively permeable membrane for the separation or enrichment of gaseous mixtures may be formed from amorphous polymers of perfluoro-2,2-dimethyl-1,3-dioxole, especially copolymers with a complementary amount of at least one of tetrafluoroethylene, perfluoromethyl vinyl ether, vinylidene fluoride and chlorotrifluoroethylene. Preferably, the polymer is a dipolymer containing 65-99 mole % of perfluoro-2,2-dimethyl-1,3-dioxole and having a glass transition temperature of at least 140.degree. C. The membranes may be used for the separation or enrichment of a wide variety of gaseous mixtures, including oxygen enrichment of air, and separation or enrichment of gaseous organic compounds in admixture with air, including separation or enrichment of the amount of fluorocarbon gases in air. The membranes exhibit a very high flux rate, compared with other glassy organic polymer membranes.