Chapter 2: Ring-opening Polymerization Promoted by Brønsted Acid Catalysts

The variety of Brønsted acids (BAs) capable of promoting controlled ring-opening polymerization of heterocyclic monomers (mainly lactones and cyclic carbonates) has been significantly enlarged over the last decade. In this chapter, the different sub-classes of BAs shown to promote this transformation are presented, focusing on their behavior in polymerization (scope of monomers and performances in terms of activity and polymerization control), and on their mode of action. Examples of controlled preparation of functionalized polymers and copolymers are also discussed, including the possibility to combine BA-catalyzed ring-opening polymerization with other types of polymerization.