| abstract |
Process for production of polymer blends which are suitable as filter aids and are composed of polystyrene and of crosslinked water-insoluble polyvinylpyrrolidones via processing of the two components in an extruder, which comprises melting polystyrene in an extruder and then treating it with the polyvinylpyrrolidone, and adding, to the mixture of the components, from 0.1 to 10% by weight of water, based on the total amount of polystyrene and popcorn polymer, and extruding and comminuting the mixture. |