Polystyrene

Abstract

Styrene, ethyl benzene and cis-polybutadiene (for high impact grade) are added and kept in a dissolver for 6-8 hours to ensure a complete dissolution of the rubber. This mixture is filtered and fed to the first of two reactors maintained at l120C where the conversion is 8.7 (maintaining the solution beyond the phase inversion point). In the second reactor, 95 r percent of the styrene is converted by the end of the react ion, when the temperature has risen to about 1650C. Polymerisation is completed in a finishing column held at 2200C for 1-2 hours followed by cooling, extrusion and pelletising.