The invention relates to a preparation method of a high-
toughness nanofiltration membrane, and belongs to the technical field of separation membrane preparation. According to the invention, the methodcomprises the following steps of melting and dispersing N,N'-dicyclohexylcarbodiimide in an
adipic acid solution; dropwise adding methoxybenzoic acid diphenol monoester after dispersing, conducting heating, mixing and stirring; after stirring, performing suction
filtration and
drying to obtain a
filter cake; mixing the
filter cake with
thionyl chloride; conducting heating condensation
reflux reaction, conducting concentrating in vacuum to obtain a
reflux product; mixing and stirring the
reflux product and
chitosan at a low temperature, and conducting freezing; conducting filtering in a freezing state to obtain a modified
filter cake; and finally, mixing the modified filter cake with
chitosan and
acetic acid, and after mixing,
coating a glass plate with the mixture and conducting
drying toobtain the high-
toughness nanofiltration membrane. According to the preparation method,
polysulfone and N,N'-dicyclohexylcarbodiimide are used for modifying
chitosan, so that a charged group is introduced into the chitosan, the interception capability of the
nanofiltration membrane is enhanced, and an
amide group is generated on a chitosan molecule through reaction, so that the
mechanical strength and the
chemical stability of the nanofiltration membrane are enhanced.