| abstract |
Provided is a composite semipermeable membrane, comprising: a microporous support membrane which comprises a substrate and a porous support, and a polyamide separation functional layer formed on the microporous support membrane, wherein the polyamide has an irreversible heat absorption, which is measured using temperature modulated DSC, of 275 J/g or more at a temperature in the range of −20 to 150° C. in the first heating process. n Provided is a high-performance composite semipermeable membrane having high chemical durability, high water permeation and high rejection. |