ABSTRACT
Living carbocationic polymerization has been one of the most rapidly developing fields in ionic polymerization in recent years. However, al though a large number of systems have been reported which allow prepara tion of homopolymers and copolymers with predetermined molecular weights, low polydispersities, and desired end functionalities, the under standing of the fundamentals of these reactions has not been adequate. It must be admitted that some time ago both co-authors of this chapter had quite different views on the mechanism of the reactions involved from what is presented in this chapter. However, a new picture emerged with time, with new experimental results, and with ample supporting evidence coming from model studies covered in Chapter 2 and from conventional cationic polymerization and related processes described in Chapter 3. As will be discussed later, these reactions are quite similar to many cationic ring-opening polymerizations (Chapter 6) in which a variety of equilibria between active and dormant species exist. To clarify our views on living carbocationic polymerizations we decided to describe them separately from conventional systems (Chapter 3) and divide the discussion ihio five sections.
