Patent ID: 6623639
Filing Date: 2003-09-23
Classification: B01D,B65D

Abstract:
A method of making a polybenzimidazole microporous hollow fiber membrane comprising the steps:(a) providing a polymer solution comprising 15 to 30 wt % polybenzimidazole, 2 to 5 wt % high molecular weight pore-former having a molecular weight of &gE;1000 daltons, 5 to 30 wt % low molecular weight pore-former having a molecular weight of &lE;100 daltons, and a solvent; (b) forming a spun membrane by extruding said polymer solution of step (a) through an orifice at a temperature of 25Â° to 60Â° C. while simultaneously injecting a coagulating fluid through a needle located in said orifice; (c) providing a quench bath; (d) passing the spun membrane of step (b) through said quench bath at a temperature of from 10Â° to 40Â° C. to form a microporous hollow fiber membrane; and (e) rinsing said membrane of step (d).