| abstract |
A hollow polysulfonic fiber intended for a selectively transmissive membrane contains a hydrophilic polymer which is cross-linked into a water-insoluble form (for example polyvinylpyrrolidone) and is used in the form of a hydrogel containing water. A method for the production of a membrane module consists in spinning a hollow fiber by the use of a spinning solution containing a polysulfonic resin and a hydrophilic polymer, wetting the fiber above the saturated moisture content, and then, with the wet condition maintained, subjecting the fiber to the processes of module molding and radiation induced cross-linking, these processes being performed in either order. The method provides a selectively transmissive hollow polysulfone fiber membrane which displays less elution into water and a sharp molecular weight fractionation, so as to be usable safely in the fields of medicine and foodstuffs. |