FOERFARANDE Foer AV polymerisation of vinylchloride in EN WATER UNDER SUSPENSION ANVAENDNING AV DIALKYLPEROXIDIKARBONATER OCH GENOM Behandling AV Polymer MED EN Hydroxide

摘要

1496848 Removal of monomer from polyvinyl chloride SOLVAY ET CIE 7 May 1976 [26 May 1975] 18785/76 Heading C3P A process for preparing vinyl chloride polymers with reduced residual monomer content comprises polymerizing the monomer in aqueous suspension in the presence of at least one dialkyl peroxydicarbonate and then removing the unreacted vinyl chloride monomer by degassing wherein the polymer suspension is treated with a monobasic hydroxide when the end of the polymerization has been reached but before the completion of degassing. The preferred hydroxides are those of ammonium, lithium, potassium and sodium which are added in such amount that the pH is from 7-12, preferably 9-10À5. The stripping may be effected using a fluid, e.g. steam.