Acid-resistant and alkali-resistant composite nanofiltration membrane, and preparation method therefor and use thereof

Abstract

The acid-resistant and alkali-resistant composite nanofiltration membrane includes a bottom layer, a porous middle layer and a poly(triazine amine-urea) separation layer in sequence. The poly(triazine amine-urea) separation layer has a structural unit I from a polyamine compound, a structural unit II from a triazine compound containing a C—Cl bond, and a structural unit III from a polyisocyanate compound. The structural unit I and the structural unit II are connected via a structure of formula (I). The structural unit I and the structural unit III are connected via formula (II); and at least one compound of the polyamine compound, the triazine compound containing a C—Cl bond, and the polyisocyanate compound contains 3 or more reaction groups. The separation layer of the acid-resistant and alkali-resistant composite nanofiltration membrane has a triazine ring, the structure of formula (III) and also the structure of formula (IV).

Dependencies are inferred from the claim text.