Ring-opening polymerization of a macrocyclic lactone monomer isolated from oligomeric byproducts of poly(butylene succinate) (PBS): An efficient route to high-molecular-weight PBS and block copolymers of PBS

A macrocyclic lactone (BSD) consisting of butylene succinate dimer was successfully isolated from oligomeric byproducts of poly(butylene succinate) (PBS) prepared by the polycondensation method. BSD was subjected to ring-opening polymerization (ROP) with tin octoate as the catalyst to obtain PBS. Its number-average molecular weight was found to reach about 9.5 × 10４ Da, being much higher than that of the PBS sample obtained by direct melt polycondensation. When the ROP of BSD was performed in the presence of polyethylene glycol (PEG) as the macro-initiators, triblock (PBS-PEG-PBS) and diblock (PEG-PBS) copolymers were obtained.