Preparation and Polymerization of Macrocyclic Oligomers

Abstract

Ring-opening polymerization reactions (Equation 1) constitute an important class of polymerization techniques. A number of commercial products are prepared via ringopening polymerization reactions, and the preparation of monomers, studies of catalysis and mechanism, and product development of many of these materials are active areas of academic and industrial research. Ring-opening polymerization chemistry has been extensively reviewed in several monographs, 1 and in many review articles.2 A wide variety of monomers have been utilized in ring-opening reactions; these polymerizations are commercially utilized for the preparation of polyamides, aliphatic polyesters, silicones, polyalkylenes (via ring-opening methathesis polymerizations), and epoxide thermosets. For this paper, discussion will be limited to three categories of ring-opening polymerization reactions: monomelic strained ring systems, which have high reaction exotherms, monomelic medium ring systems, which have moderate exotherms, and oligomeric large ring systems, which have little or no reaction exotherm.