PROCESS FOR THE REMOVAL OF NON-CONVERTED MONOMERS FROM A COPOLYMER OF ACRYLONITRILE

摘要

A process for the removal of unconverted monomers from copolymers of acrylonitrile and one or more monomer copolymerizable therewith, wherein a suspension of polymer particles is continuously and countercurrently contacted with steam in a gas-liquid contacting device e.g. a sieve-tray column at a temperature of 95-150 DEG C and a pressure of 75-500 kPa. The process may be applied to suspensions obtained from mass, solution, suspension or emulsion polymerizations producing for example styrene/acrylonitrile and graft acrylonitrile copolymers on a rubber.