PVC Resin: Vinyl Chloride Polymerised in Water without Emulsifier

PVC resin is polyvinyl chloride as small granules. Lightfoot's method (US 2,511,593, 1950) needs no soap or other emulsifier: liquid vinyl chloride is stirred hard in water with a little potassium persulfate at 50 °C under its own vapour pressure, and the polymer comes out as granules that settle and are simply washed and dried. The patent's example made 4.5 lb from 9.9 lb of monomer. The picture: our diagram.