RADIATION-INITIATED INVERSE EMULSION POLYMERIZATION OF VINYLPYRROLIDONE

The radiation-induced inverse emulsion polyerization of vinylpyrrolido ne using an isoparaffinic hydrocarbon and nonionic emulsifier blend is described. High molecular weight polyvinylpyrrolidone (PVP) (1 millio n to 2 million M(upsilon) was readily obtained at rapid polymerization rates (Rp approximately 10-35 mol 1(-1) s-1) to high conversions (90- 95%). The polydispersity of the polymer varied from 2.6 to 4.4, sugges ting that chain transfer to the polymer had occurred. Adding a polymer ic surfactant to the nonionic blend modified the polymerization rate a nd particle-size distribution. (C) 1994 John Wiley & Sons, Inc.