Abstract: The polyimide blend membrane in the present invention was prepared by blending a first aromatic polyimide with high permeability and a second aromatic polyimide with high selectivity for gas separation. The polyimide blend membrane in the present invention showed improved permeability compared to membranes made from the second aromatic polyimide and improved selectivity compared to membranes made from the first aromatic polyimide.

Abstract: The polyimide blend membrane in the present invention was prepared by blending a first aromatic polyimide with high permeability and a second aromatic polyimide with high selectivity for gas separation. The polyimide blend membrane in the present invention showed improved permeability compared to membranes made from the second aromatic polyimide and improved selectivity compared to membranes made from the first aromatic polyimide.

Abstract: Polyimide membranes are provided that provide extremely high permeability. The polyimides do not contain carbonyl or sulfonyl functional groups. These membranes are useful in separating gases including the separation of gas pairs including carbon dioxide/methane, hydrogen/methane and propylene/propane as well as other gas mixtures. The membrane selectivity can be adjusted by exposure to ultraviolet light.

Abstract: Polyimide membranes are provided that provide extremely high permeability. The polyimides do not contain carbonyl or sulfonyl functional groups. These membranes are useful in separating gases including the separation of gas pairs including carbon dioxide/methane, hydrogen/methane and propylene/propane as well as other gas mixtures. The membrane selectivity can be adjusted by exposure to ultraviolet light.

Abstract: An asymmetric integrally-skinned flat sheet membrane comprising a miscible blend of an aromatic polyethersulfone (PES) polymer and an aromatic polyimide polymer is used for gas separations such as hydrogen purification, separation of hydrogen and methane and to separate other gases and liquids. UV radiation may be applied to the surface of the membrane for improved properties.

Abstract: An asymmetric integrally-skinned flat sheet membrane comprising a miscible blend of an aromatic polyethersulfone (PES) polymer and an aromatic polyimide polymer is used for gas separations such as hydrogen purification, separation of hydrogen and methane and to separate other gases and liquids. UV radiation may be applied to the surface of the membrane for improved properties.

Abstract: This invention relates to high hydrocarbon resistant chemically cross-linked aromatic polyimide polymers, membranes and methods for making and using these polymers and membranes. The high hydrocarbon resistant chemically cross-linked aromatic polyimide membrane described in the present invention comprises a plurality of repeating units of a first aromatic polyimide comprising hydroxyl groups cross-linked with a second aromatic polyimide comprising carboxylic acid groups via covalent ester bonds. These membranes exhibit high permeability and selectivity in separation of mixtures of gases and liquids.

Abstract: A polyimide polymer having hydroxyl and acetoxy function groups is provided together with a membrane made from the polymer. Also provided is a process for separating at least one gas from a mixture of gases using a polyimide membrane comprising a polyimide polymer with hydroxyl and acetoxy functional the process comprising: (a) providing the polyimide membrane comprising the polyimide polymer with hydroxyl and acetoxy functional groups which is permeable to the at least one gas; (b) contacting the mixture on one side of the polyimide membrane to cause said at least one gas to permeate the membrane; and (c) removing from the opposite side of the membrane a permeate gas composition comprising a portion of said at least one gas which permeated the polyimide membrane.

Abstract: The present invention involves a type of nanoporous macrocycle-containing cross-linked polymeric membrane, a method of making the membrane, and the use of such a novel membrane system for natural gas liquids (NGL) recovery, fuel gas conditioning, natural gas pre-treatment, sulfur removal from fluidized catalytic cracking (FCC) and other naphtha streams, as well as aromatic separations such as aromatic/paraffin separation and xylene separation. The nanoporous macrocycle-containing cross-linked polymeric membrane is prepared from a diisocyanate-terminated polyether or a diisocyanate-terminated polyester, that is crosslinked with a nanoporous macrocycle comprising hydroxyl functional groups such as ?-, ?-, and ?-cyclodextrins.

Abstract: The invention is a process of making a chemically and UV treated polymer of intrinsic microporosity membrane comprising preparing a polymer of intrinsic microporosity, chemically cross-linking said polymer of intrinsic microporosity with a cross-linking compound to produce a chemically cross-linked polymer of intrinsic microporosity and then treating said chemically cross-linked polymer with UV radiation for a period of time sufficient to provide a product membrane. This product membrane is useful in the separation of C3 and higher hydrocarbons, as well as CO2, from natural gas and other gas streams.

Abstract: A polyimide polymer having hydroxyl and acetoxy function groups is provided together with a membrane made from the polymer. Also provided is a process for separating at least one gas from a mixture of gases using a polyimide membrane comprising a polyimide polymer with hydroxyl and acetoxy functional the process comprising: (a) providing the polyimide membrane comprising the polyimide polymer with hydroxyl and acetoxy functional groups which is permeable to the at least one gas; (b) contacting the mixture on one side of the polyimide membrane to cause said at least one gas to permeate the membrane; and (c) removing from the opposite side of the membrane a permeate gas composition comprising a portion of said at least one gas which permeated the polyimide membrane.

Abstract: A method of making a polybenzoxazole (PBO) membrane from a self-cross-linked aromatic polyimide polymer membrane is provided. These membranes are useful in the separation of gas mixtures and liquid mixtures. The PBO membrane is made by fabricating a self-cross-linkable aromatic polyimide polymer membrane comprising both hydroxyl functional groups and carboxylic acid functional groups; cross-linking the polymer to form a self-cross-linked aromatic polyimide polymer membrane by heating the membrane at 250° to 300° C. under an inert atmosphere; and thermal heating the self-cross-linked aromatic polyimide polymer membrane at a temperature from about 350° to 500° C. under an inert atmosphere to convert the self-cross-linked aromatic polyimide polymer membrane into a PBO membrane. A membrane coating step may be added by coating the selective layer surface of the PBO membrane with a thin layer of high permeability material.

Abstract: A separation membrane is described. The separation membrane comprises a porous inorganic membrane, the pores of the inorganic membrane being coated with a polybenzoxazole polymer coating. Methods of making the separation membrane and methods of separating xylenes using the separation membrane are also described.

Abstract: A copolyimide membrane is provided by the present invention that is effective in separating olefins and paraffins. The membrane with very high selectivity and permeability in the present invention is used in a process for separating olefins from a mixture of olefins and paraffins, the process comprising providing a copolyimide membrane with very high selectivity and high permeability described in the present invention which is permeable to said olefin; (b) contacting the olefin/paraffin mixture on one side of the copolyimide membrane with very high selectivity and high permeability described in the present invention to cause the olefin to permeate the membrane; and (c) removing from the opposite side of the membrane a permeate gas composition comprising a portion of the olefin which permeated through the membrane. Ethylene, propylene, butene, or pentene is separated from ethane, propane, butane, or pentane, respectively with up to 99 mole % olefin content in the permeate.

Abstract: A method of making a polybenzoxazole (PBO) membrane from a self-cross-linked aromatic polyimide polymer membrane is provided. These membranes are useful in the separation of gas mixtures and liquid mixtures. The PBO membrane is made by fabricating a self-cross-linkable aromatic polyimide polymer membrane comprising both hydroxyl functional groups and carboxylic acid functional groups; cross-linking the polymer to form a self-cross-linked aromatic polyimide polymer membrane by heating the membrane at 250° to 300° C. under an inert atmosphere; and thermal heating the self-cross-linked aromatic polyimide polymer membrane at a temperature from about 350° to 500° C. under an inert atmosphere to convert the self-cross-linked aromatic polyimide polymer membrane into a PBO membrane. A membrane coating step may be added by coating the selective layer surface of the PBO membrane with a thin layer of high permeability material.

Abstract: The present invention involves a type of nanoporous macrocycle-containing cross-linked polymeric membrane, a method of making the membrane, and the use of such a novel membrane system for natural gas liquids (NGL) recovery, fuel gas conditioning, natural gas pre-treatment, sulfur removal from fluidized catalytic cracking (FCC) and other naphtha streams, as well as aromatic separations such as aromatic/paraffin separation and xylene separation. The nanoporous macrocycle-containing cross-linked polymeric membrane is prepared from a diisocyanate-terminated polyether or a diisocyanate-terminated polyester, that is crosslinked with a nanoporous macrocycle comprising hydroxyl functional groups such as ?-, ?-, and ?-cyclodextrins.

Abstract: This invention relates to high hydrocarbon resistant chemically cross-linked aromatic polyimide polymers, membranes and methods for making and using these polymers and membranes. The high hydrocarbon resistant chemically cross-linked aromatic polyimide membrane described in the present invention comprises a plurality of repeating units of a first aromatic polyimide comprising hydroxyl groups cross-linked with a second aromatic polyimide comprising carboxylic acid groups via covalent ester bonds. These membranes exhibit high permeability and selectivity in separation of mixtures of gases and liquids.

Abstract: The present invention discloses a new type of high performance polymer membranes prepared from aromatic polyimide membranes by thermal treating and crosslinking and methods for making and using these membranes. The polymer membranes were prepared from aromatic polyimide membranes by thermal treating under inert atmosphere followed by crosslinking preferably by using a UV radiation source. The aromatic polyimide membranes were made from aromatic polyimide polymers comprising both pendent hydroxy functional groups ortho to the heterocyclic imide nitrogen and cross-linkable functional groups in the polymer backbone. The membranes showed significantly improved selectivity and permeability for gas separations compared to the aromatic polyimide membranes without any treatment. The membranes can be fabricated into any convenient geometry and are not only suitable for a variety of liquid, gas, and vapor separations, but also can be used for other applications such as for catalysis and fuel cell applications.

Abstract: This invention relates to high hydrocarbon resistant chemically cross-linked aromatic polyimide polymers, membranes and methods for making and using these polymers and membranes. The high hydrocarbon resistant chemically cross-linked aromatic polyimide membrane described in the present invention comprises a plurality of repeating units of a first aromatic polyimide comprising hydroxyl groups cross-linked with a second aromatic polyimide comprising carboxylic acid groups via covalent ester bonds. These membranes exhibit high permeability and selectivity in separation of mixtures of gases and liquids.

Abstract: A polybenzoxazole (PBO) membrane from a self-cross-linked aromatic polyimide polymer membrane is provided. These membranes are useful in the separation of gas mixtures. The PBO membrane is made by fabricating a self-cross-linkable aromatic polyimide polymer membrane comprising both hydroxyl functional groups and carboxylic acid functional groups; cross-linking the polymer to form a self-cross-linked aromatic polyimide polymer membrane by heating the membrane at 250° to 300° C. under an inert atmosphere; and thermal heating the self-cross-linked aromatic polyimide polymer membrane at a temperature from about 350° to 500° C. under an inert atmosphere to convert the self-cross-linked aromatic polyimide polymer membrane into a PBO membrane. A membrane coating step may be added by coating the selective layer surface of the PBO membrane with a thin layer of high permeability material.