SYNTHESIS OF POLYSTYRENES WITH DIFFERENT STEREO-REGULARITIES BY ANIONIC-POLYMERIZATION

In the reported experimental study, the stereoregularity of PS prepared by anionic polymerization was determined by means of **1**3C-NMR spectroscopy. The stereoregularity changed with such polymerization conditions as catalyst, solvent, and temperature. Sodium naphthalene as catalyst gave a syndiotactic-rich PS of 66 - 68% syndiotactic dyads independently of solvent and temperature, while potassium and cesium naphthalenes as catalyst produced PS with different stereoregularities ranging from syndiotactic-rich to isotactic-rich configurations, depending on solvent and temperature. The mechanism of anionic polymerization which caused the difference in stereoregularity was discussed from the viewpoint of growing ionic species.