METHOD FOR THE PRODUCTION OF CO-EXTRUDATES COMPOSED OF POLYSTYRENE AND OF A CROSSLINKED POLYVINYLPYRROLIDONE WITH REDUCED RESIDUAL STYRENE MONOMER CONTENT

摘要

Method for the removal of residual styrene monomers from polystyrene and from co-extrudates comprising crosslinked polyvinylpyrrolidone which is not soluble in water, characterized in that an aqueous suspension of the particulate solid co-extrudate is subjected to heat treatment at temperatures from 60 to 99°C, where the ratio by weight of solid co-extrudate to water in the suspension is from 1:1.5 to 1:20, and the concentration of the suspension is held constant during the treatment.