Green Synthesis of Chemically Recyclable Polyesters via Dehydrogenative Copolymerization of Diols

Preparation of chemically recyclable polyesters by ring-opening polymerization (ROP) has made a considerable progress over the past few years. However, this method involves cumbersome synthesis and minimal functional diversity of cyclic monomers. Therefore, it is of great significance to develop novel polymerization methods for direct polymerization of commercially available monomers to prepare recyclable polyesters with versatile functionalities. In present work, we report dehydrogenative copolymerization of commercial alpha,omega-diols to afford high molecular weight chemically recyclable aliphatic copolyesters (65.7 kg center dot mol(-1)) by using commercially available Milstein catalyst precursor. The thermal properties of the obtained copolymers could be finely tuned by simply adjusting the feeding ratio of two monomers. The incorporation of aliphatic or aromatic rings into polyester mainchain via copolymerization of 1,10-decanediol with 1,4-cyclohexanedimethanol and 1,4-benzenedimethanol could significantly improve the thermal properties of the resulting copolymers. More importantly, the obtained copolyesters were able to completely depolymerize back to original diols via hydrogenation by the same catalyst in solvent-free and mild conditions, thus offering a green and cost-effective route toward the preparation of widely used polyesters.