Poly(vinyl alcohol)-g-poly(sodium allylsulfonate/acrylamide) (PVA-g-PSAS/AM) were synthesized by free radical polymerization. The PVA-g-PSAS/AM was degraded into poly(vinyl alcohol)-g-poly(sodium allylsulfonate/vinylamine) (PVA-g-PSAS/VA), which was PVA based polyampholyte (PBPA). The PBPA homogeneous membrane was characterized by FT-IR and SEM. The isoelectric point of PBPA was pH=6. Surface hydrophilicity of membranes was examined by automated contact angle measurement device. At 90 °C, the PBPA membrane showed a separation factor of 991 and a flux of 1140g/(m2·h) for 90 wt.% ethanol aqueous solution, while about 1491 and 970 g/(m2·h) for 90 wt.% isopropanol aqueous solution.
