Abstract: The common aromatic polyamide composite reverse osmosis(RO) membrane is easy to be oxidated. N,N'-dimethyl-m-phenylenediamine(DMMPD) as a key functional monomer could be reacted with 5-choroformyloxyisophthaloyl chloride(CFIC) to prepare a chlorine resistance polyimide-urethane RO membrane material by interfacial polymerization technology. In this study, the membrane formation conditions such as solvent of aqueous phase, composition and concentration of amine in aqueous phase, and contact time of two phases were optimized. The results show that the NaCl rejection rate of DMMPD-CFIC membrane prepared from only DMMPD is not ideal, but the combination of DMMPD and 4-methyl-m-phenylenediamine(MMPD) at a mass ratio of 1∶2 to prepare the MMPD/DMMPD-CFIC membrane can obviously improve the NaCl rejection of the resulting membrane, and the chlorine resistance performance of membrane just has slight change. Furthermore, the surface chemical structure of membrane active layer was analyzed by combination of attenuated total reflectance infrared(ATR-FTIR) and X-ray photoelectronic spectroscopy(XPS), and the surface morphology of membrane was observed via scanning electronic microscopy(SEM) and atomic force microscope(AFM).

Key words: Polyimide-urethane, Reverse osmosis composite membrane, Surface morphology, Separation performance, Chlorine-resistance performance