Abstract: A method for separation of liquid mixtures with a polybenzoxazole (PBO) membrane from a self-cross-linked aromatic polyimide polymer membrane is provided.

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 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 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.

Abstract: This invention relates to self-cross-linkable and self-cross-linked aromatic polyimide polymers, their membranes and methods for making and using these polymers and membranes. The self-cross-linkable aromatic polyimide polymer described in the present invention comprises both hydroxyl functional groups and carboxylic acid functional groups. The self-cross-linked aromatic polyimide was formed via heating the self-cross-linkable aromatic polyimide polymer at ?300° C. The self-cross-linked aromatic polyimide membranes exhibit high selectivity in separation of mixtures of gases and liquids.

Abstract: This invention relates to self-cross-linkable and self-cross-linked aromatic polyimide polymers, their membranes and methods for making and using these polymers and membranes. The self-cross-linkable aromatic polyimide polymer described in the present invention comprises both hydroxyl functional groups and carboxylic acid functional groups. The self-cross-linked aromatic polyimide was formed via heating the self-cross-linkable aromatic polyimide polymer at ?300° C. The self-cross-linked aromatic polyimide membranes exhibit high selectivity in separation of mixtures of gases and liquids.

Abstract: This invention relates to self-cross-linkable and self-cross-linked aromatic polyimide polymers, their membranes and methods for making and using these polymers and membranes. The self-cross-linkable aromatic polyimide polymer described in the present invention comprises both hydroxyl functional groups and carboxylic acid functional groups. The self-cross-linked aromatic polyimide was formed via heating the self-cross-linkable aromatic polyimide polymer at ?300° C. The self-cross-linked aromatic polyimide membranes exhibit high selectivity in separation of mixtures of gases and liquids.

Abstract: This invention relates to self-cross-linkable and self-cross-linked aromatic polyimide polymers, their membranes and methods for making and using these polymers and membranes. The self-cross-linkable aromatic polyimide polymer described in the present invention comprises both hydroxyl functional groups and carboxylic acid functional groups. The self-cross-linked aromatic polyimide was formed via heating the self-cross-linkable aromatic polyimide polymer at ?300° C. The self-cross-linked aromatic polyimide membranes exhibit high selectivity in separation of mixtures of gases and liquids.

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 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 generally relates to high permeability, UV cross-linkable copolyimide polymers and membranes for gas, vapor, and liquid separations, as well as methods for making and using these membranes. The invention provides a process for separating at least one gas from a mixture of gases using the high permeability copolyimide membrane or the UV cross-linked copolyimide membrane, the process comprising: (a) providing a high permeability copolyimide membrane or a UV cross-linked copolyimide membrane which is permeable to said at least one gas; (b) contacting the mixture on one side of the high permeability copolyimide membrane or the UV cross-linked copolyimide 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 said membrane.

Abstract: The present invention discloses high performance cross-linked polyimide asymmetric flat sheet membranes and a process of using such membranes. The cross-linked polyimide asymmetric flat sheet membranes have shown CO2 permeance higher than 80 GPU and CO2/CH4 selectivity higher than 20 at 50° C. under 6996 kPa of a feed gas with 10% CO2 and 90% CH4 for CO2/CH4 separation.