A Renaissance in Living Cationic Polymerization

Advances in living polymerization initiators, including the design and synthesis of a variety of new polymers, with a focus on the most recent developments, are reviewed. The fabrication of macromolecular aggregates that display various functions and properties will become increasingly important in the development of polymer synthesis. To accomplish this, it will be necessary to design and synthesize polymers in which the primary structure, including monomer sequences and stereoregularity, is precisely controlled. The importance of the choice of acid catalysts (activator) was shown in cationic polymerization of styrene and its derivatives. It was then known that molecular weight of product polymers became higher when a polar solvent was used. Successful catalytic processes were achieved using metal triflates in the 1990s. Efficient acylation proceeded with a catalytic amount of triflates of Ti, 58 Hf, 59,60 Sc, 61,62 and lanthanides. The development of new polymerization catalyst systems that will serve as the basis for this will be indispensable.