Cyclodepolymerization of polyesters for the synthesis of macrocyclic oligomers

Macrocyclic oligomers (MCOs) of polycondensates are important starting materials for entropically-driven ring-opening polymerization (ED-ROP) reactions which have gained interest in different fields, such as injection/reactive moulding. A general method for their synthesis is the cyclodepolymerization (CDP) at high dilution of the parent polymer by using traditional transesterification catalysts typically based on Sn compounds. This research aims at obtaining MCOs from biodegradable polyesters, such as polybutylene adipate terephthalate (PBAT) and polybutylene succinate (PBS), through CDP reactions carried out in green solvents and/or with non-toxic Zn- and Ti-based catalysts. Preliminary results were compared with those performing CDP with chloroform and n-Bu2SnO as benchmark solvent and catalyst, respectively.