PROCESS FOR MAKING CROSSLINKED POLYVINYLPYRROLIDONE WITH LOW SWELL VOLUME

摘要

A two-step, base-catalyzed process for making crosslinked polyvinylpyrrolidone (PVP-P) having a low swell volume is disclosed. A crosslinker is generated "in situ" in the first step by heating a basic aqueous mixture containing a relatively low concentration of N-vinylpyrrolidone under added inert gas pressure. In a second step, the reactor temperature is reduced to initiate polymerization. The process is a productive way to make PVP-P that is easy to isolate and purify. The polymer has a swell volume less than about 40 mL H2O/1O g polymer, which makes it valuable for beverage clarification.