SEMIPERMEABLE OSMOTIC MEMBRANE AND METHOD OF PRODUCING SAME

摘要

Semipermeable membranes prepared from a mixture of vinylpyrrolidone polymers and polyisocyantes. Process for preparing such membranes by casting the mixture from solution onto a smooth surface followed by curing under conditions of controlled humidity. Reaction of polyisocyanates with certain compounds having an active hydrogen atom provides a "blocked" polyisocyanate which does not react immediately with water at ambient temperatures thereby allowing greater processing control of membrane production.