▎ 摘　　要

NOVELTY - A gas-separation membrane comprises a porous substrate, and a discriminating layer in contact with the porous substrate. The discriminating layer is obtained by curing a composition containing a curable copolymer. The curable copolymer comprises m number of epoxide groups and n number of poly(ethylene oxide) groups (I). USE - Membrane used in gas-separation module used for separating gases e.g. polar and non-polar gases and/or for purifying feed gas (all claimed) e.g. natural gas, and flue gas. ADVANTAGE - The gas separation membrane is inexpensive, and efficiently produced at high speed in a simple way, is capable of discriminating well between gases, and has excellent strength, flexibility, and high permeability. DETAILED DESCRIPTION - A gas-separation membrane comprises a porous substrate, and a discriminating layer in contact with the porous substrate. The discriminating layer is obtained by curing a composition containing a curable copolymer. The curable copolymer comprises m number of epoxide groups and n number of poly(ethylene oxide) groups of formula (I): (CH2CH2O)q. q=4-23;and m+n=550-2600. INDEPENDENT CLAIMS are included for the following: manufacture of the gas separation membrane, which involves impregnating a porous substrate with the composition, and, curing the composition; and a gas-separation module, which comprises the gas-separation membrane.