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

摘要

The present disclosure relates to a crosslinked, thermally rearranged poly(benzoxazole-co-imide) copolymer membrane prepared simply by heat-treating a membrane prepared from an o-hydroxypolyimide copolymer having carboxylic acid groups such that thermal crosslinking and thermal rearrangement occur simultaneously or a gas separation membrane containing a crosslinked, thermally rearranged poly(benzoxazole-co-imide) copolymer having a benzoxazole group content of less than 80% in the polymer chain, prepared from transesterification crosslinking of an o-hydroxypolyimide copolymer having carboxylic acid groups and a diol-based compound followed by thermal rearrangement, and a method for preparing the same (a membrane for flue gas separation is excluded). In accordance with the present disclosure, a crosslinked, thermally rearranged poly(benzoxazole-co-imide) copolymer membrane for gas separation can be prepared simply through heat treatment without requiring a complicated process such as chemical crosslinking, UV irradiation, etc. for forming a crosslinked structure and a gas separation membrane (a membrane for flue gas separation is excluded) prepared therefrom exhibits superior permeability and selectivity. Also, the method is applicable to commercial-scale production because the preparation process is simple.