Sulfonated polyethyleneimine and nanofiltration membrane, and preparation methods thereof

[0030] 1 g of polyethyleneimine (PEI, molecular weight: 600 Da, purity: 99%, Shanghai Aladdin Reagent Company) was added into a 100 mL round bottom flask, and then 50 mL of absolute ethanol solution was slowly added. Stir magnetically until the PEI is completely dissolved to obtain a colorless and transparent solution, then add 1 g of 1,3 propane sultone (purity: 99%, Shanghai Aladdin Reagent Company) and 0.416 mL of ammonia solution to the solution in sequence, at 50 ° C After continuing to stir the reaction for 24h, a viscous ethanol solution of sulfonated polyethyleneimine (SPEI) was obtained. Finally, by filtration and freeze-drying, the SPEI solid with a sulfonation degree of 15.8% was obtained and stored in a desiccator.

[0032] The difference from Example 1 is that the amount of propane sultone added is 0.5 g, and the sulfonation degree is 7.5%.

[0034] The difference from Example 1 is that the amount of propane sultone added is 2 g, and the sulfonation degree is 32.7%.