Abstract:
Controlled ring-opening polymerization (ROP) of cyclic mono and diesters provides an access to a wide range of aliphatic polyesters with a diversity of chemical and physical properties. Under optimum conditions, ROPs produce polymers with predictable and high molecular weight, narrow molecular weight distribution and controlled chain end functionality. Furthermore, polymers with a wide variety of macromolecular architectures, such as, homo-, random-, block-, multiblock, mikto-arm, multi-arm star-branched, and hyper-banched polymers can be synthesized. By appropriate choice of monomers, controlling their chain length and sequence of enchainment as well as their molecular architecture, one can prepare useful polyesters with a balance of molecular, supramolecular, thermal, rheological and mechanical properties. In this Chapter, we review recent developments in the area of synthesis and properties of a range of polyesters prepared by controlled ROP. These include, block copolymers, multi-arm, star-branched, homo-, random- and block copolymers, mikto-arm polymers and star-branched ionomers. Potential applications of these polymers in improving some of the deficiencies in properties of poly (lactic acid), one of the large volumes commercial, biorenewable, and biocompatible and biodegradable polymers are highlighted.