USE OF TETRAFUNCTIONAL INITIATORS TO IMPROVE THE RUBBER PHASE VOLUME OF HIPS

摘要

It has been discovered that improved polystyrene products, such as high impact polystyrene (HIPS), may be obtained by polymerizing styrene with a diene polymer in the presence of at least one multifunctional initiator. The presence of the multifunctional initiator tends to cause more branched structures in the polystyrene. Unexpectedly, the ratio of % gel to % rubber (G/R or rubber phase volume) increases as the swell index increases which is the opposite of the conventional trend. Additionally, acceptable G/R values can be achieved at increased polymerization rates with these initiators.