Direct Organocatalytic Ring-Opening Polymerizations of Lactones

We have developed a novel organocatalytic, direct synthesis of aliphatic polyesters. The synthesis was based on a novel direct organic acid‐catalyzed living ring‐opening polymerization (ROP) of ε‐caprolactone and δ‐valerolactone with benzyl alcohol as the initiator. The organic acid‐catalyzed ROPs were performed without solvent and the catalyst was recovered by precipitation of the polyester products. In addition, they were operationally simple, inexpensive and environmentally benign. Organic acid catalysis provides a new entry for the synthesis of valuable biodegradable materials as well as polyesters for biomedical applications.