| abstract |
Organic reinforcing fillers for rubber are prepared by the anionic initiated slurry polymerization of styrene and divinylbenzene in the presence of a block polymer dispersant. The polymerization reaction may be carried out using, as the anionic initiator, an alkali metal-bearing compound capable of initiating polymerization of styrene without imparting to the polymerization product groups reactive with rubber in a rubber cure in which case the polymerization is terminated by reaction of the polymer particles with a terminating agent that provides in the polymer groups reactive with rubber in a normal rubber cure; or the polymerization reaction can be carried out using, as the initiator, an alkali metal-bearing unsaturated polymer that in itself imparts to the polymer groups reactive with rubber in a normal rubber cure. In the latter case, the slurry polymerization may, if desired, be terminated by use of a terminating agent that reacts with and imparts to the polymer additional and different groups tha enhance reactivity of the polymer particles with rubber in a rubber cure operation. |