▎ 摘　　要

NOVELTY - Preparing diamines and polyamines containing diphenylmethane structure with low acid consumption comprises (1) undergoing salt-forming reaction to generate aniline salt by aniline in the presence of acidic catalyst, (2) mixing aniline salt and formaldehyde solution for condensation reaction to obtain reaction solution containing diamine salt and polyamine salt with diphenylmethane structure, (3) adding reaction solution to the membrane separator, separating the acid catalyst in the aqueous phase with water in the form of aniline salt, and separating the aqueous phase from the organic phase of diamines and polyamines containing diphenylmethane structures, and (4) washing organic phase with alkali and distilling to obtain diamine and polyamine (DAM) containing diphenylmethane structure, removing part of the water by distillation, and returning the aqueous phase to raw material and acid catalyst for the condensation reaction. USE - The method is useful for preparing diamines and polyamines containing diphenylmethane structure with low acid consumption. ADVANTAGE - The method significantly reduces the material consumption, energy consumption and generation of waste brine in the DAM preparation process under the premise of ensuring the quality of the DAM. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: uperhydrophilic membrane adopted in the method, where the superhydrophilic membrane is modified halloysite nanotube/porous graphene oxide superhydrophilic membrane; and preparing the superhydrophilic membrane, comprising (i) adding graphene oxide (GO) powder into water to disperse, mixing the dispersion with concentrated nitric acid and continuously dispersing, centrifuging and separating, washing, filtering, and drying to prepare porous graphene oxide (pGO), (ii) dissolving dopamine in tris-hydrochloric acid solution, reacting after mixing, adjusting the pH value of the mixed solution, adding halloysite nanotubes (HNTs), reacting after dispersing, centrifuging and separating, washing, filtering, and drying to obtain modified halloysite nanotube (DHNTs), (iii) dissolving pGO in water and disperse to obtain pGO dispersion, and dissolving DHNTs in water and dispersing to obtain DHNTs dispersion, and (iv) mixing pGO dispersion with DHNTs dispersion and mixing with ethylenediamine solution after dispersion, suction filtering after dispersion, loading mixture on microporous membrane, washing and drying, and obtaining DHNTs/pGO superhydrophilic membrane.