| 摘要 |
High impact polymers are made by continuously bulk polymerizing a vinyl aromatic compound in the presence of an unvulcanized elastomer in a plurality of reactors in series, an inert diluent miscible with the polymerizing mixture being present in at least the final reactor, part of the diluent being constantly removed by evaporation from the top of the final reactor during polymerization, at least part of the resulting vapour not being refluxed to the final reactor. Elastomers specified are polybutadiene, butadiene-styrene copolymers and block copolymers of vinyl arenes and dienes. Diluents specified are benzene, toluene, xylene, ethylbenzene and cyclohexane. The examples describe the use of the process to polymerize styrene in the presence of: (1) a butadiene-styrene random copolymer, (2) a mixture of polybutadiene and butadiene-styrene copolymer, (3) a mixture of polybutadiene and a polybutadiene-polystyrene tapered block copolymer, and (4) a polystyrene - polybutadiene - polystyrene block copolymer. |
