New strategy for enzymatic synthesis of high-molecular-weight poly(butylene succinate) via cyclic oligomers

High-molecular-weight poly(butylene succinate) (PBS) is prepared by the lipase-catalyzed polymerization of dimethyl succinate and butane-1,4-diol via the formation of cyclic oligomers as a new strategy for the green production of bio-based plastics. The cyclic oligomer is first produced by the lipase-catalyzed condensation of dimethyl succinate and butane-1,4-diol in a dilute toluene solution using lipase from Candida antarctica, followed by the ring-opening polymerization of the cyclic oligomer in a more concentrated solution or in bulk with the same lipase to produce PBS with an M̄ _w of 130 000. On the other hand, PBS is produced with an M̄ _w of 45 000 by direct polycondensation.