Patent ID: 8915379
Filing Date: 2014-12-23
Classification: B01D

Abstract:
1. A method for production of a polybenzoxazole membrane with improved selectivity for gas, vapor, and liquid separations comprising first fabricating a blend membrane from a mixture of an aromatic polyimide polymer and a polymer selected from the group consisting of poly(styrene sulfonic acid), poly(trifluorostyrene sulfonic acid), and mixtures thereof, and then converting said blend membrane to a polybenzoxazole membrane by application of heat under an inert atmosphere or under vacuum, and wherein said aromatic polyimide polymer consists of a plurality of repeating units of a formula (I), wherein formula (I) is: where —X and mixtures thereof, —X and mixtures thereof, and —R— is selected from the group consisting of and mixtures thereof, and —R′— is selected from the group consisting of and mixtures thereof.