A convenient route to high molecular weight highly isotactic polystyrene using Ziegler–Natta catalysts and ultrasound

Ziegler–Natta (TiCl4/AlEt3) catalysts and ultrasound were used to prepare highly isotactic polystyrene (ca. 99%) with a molecular weight of 4.7×106 mol g−1 and low molecular weight distribution (Mw/Mn=1.6) via a convenient method. Ultrasound was most effective if applied only during an initial stage in the polymerisation, most likely permitting dispersion of catalyst particles which were subsequently coated and separated by growing polymer chains. Yields could be improved by varying the amount of catalyst and reaction time.