On the Cascade Polymerization Process Consisting of Metallocene Polymerization and ATRP to Prepare i-PP-Based Polar Block Copolymers

Isotactic poly(propylene)s bearing a terminal hydroxyl group (i-PP-t-OH) with high degrees of end-group functionality were synthesized by a met allocene/methylaluminoxane (MAO)-mediated propylene polymerization process via a preferential aluminium chain transfer reaction assisted by a hydroalumination process at the end of polymerization. Despite the highly isotactic configuration and relatively high molecular weight ((M) over bar (n) as high as 60 800 g.mol(-1)) of the polymers, the hydroxyl group located at the i-PP chain terminal was efficiently transformed to an atom transfer radical polymerization (ATRP) initiator moiety of i-PP-t-Br via a reaction with 2-bromopropionyl chloride at 60 degrees C in toluene. Well-defined i-PP-b-PMMA and i-PP-b-PS block copolymers of controllable structure and compositions were then prepared with efficient ATRPs of MMA and St using i-PP-t-Br.