THERMALLY REARRANGED POLY(BENZOXAZOLE-IMIDE) COPOLYMER HAVING CROSS-LINKED STRUCTURE, GAS SEPARATION MEMBRANE COMPRISING SAME AND PREPARATION METHOD THEREFOR

摘要

The present invention relates to: a preparation, by simple thermal treatment of a membrane prepared from an ortho-hydroxy polyimide copolymer having a carboxylic acid, of a thermally rearranged poly(benzoxazole-imide) membrane having a structure cross-linked by direct thermal cross-linking and simultaneous thermal rearrangement; a gas separation membrane comprising a thermally rearranged poly(benzoxazole-imide) copolymer having a structure, in which the content of a benzoxazole group in a copolymer chain is less than 80%, cross-linked by a transesterification cross-linking reaction of the ortho-hydroxy polyimide copolymer having a carboxylic acid with a diol-based compound and subsequent thermal rearrangement; and a preparation method therefor (however, a membrane for flue gas separation is excluded).