ULTRATHIN-FILM COMPOSITE MEMBRANE BASED ON THERMALLY REARRANGED POLY(BENZOXAZOLE-IMIDE) COPOLYMER, AND PRODUCTION METHOD THEREFOR

• Main Authors: LEE, Sang Min, LEE, Young Moo, MOON, Sun-ju, JUNG, Juntae, PARK, Sang Hyun, KIM, Jihoon, KANG, Narae, LEE, Jong Myoung, KIM, Ju-Sung
• Format: Patent
• Language: English
• Published: 17.06.2021
• Subjects: PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; SEPARATION; TRANSPORTING

The present invention relates to an ultrathin-film composite membrane based on a thermally rearranged poly(benzoxazole-imide) copolymer and a production method therefor and to a technique for forming a porous support by means of a thermally rearranged poly(benzoxazole-imide)copolymer and then producing, on the porous support, an ultrathin-film composite membrane comprising a thin-film active layer. The ultrathin-film composite membrane produced according to the present invention has excellent thermal/chemical stability and mechanical physical properties, thus is not only capable of withstanding high operating pressure, but also capable of minimizing internal concentration polarization and thereby obtaining high water permeance and, as a result, high power density, and thus can be applied to a pressure-retarded osmosis or forward osmosis process. Further, said ultrathin-film composite membrane has excellent chemical/thermal stability against organic solvents, has superior organic solvent nano-filtration performance, particularly maintains nano-filtration performance stably even under a high-temperature organic solvent condition, and thus can be applied as an organic solvent nano-filtration membrane.