Next Generation of Zinc Bisguanidine Polymerization Catalysts towards Highly Crystalline, Biodegradable Polyesters.

ABSTRACT: Polylactide and polycaprolactone are both biodegradable polymers produced through metal-catalyzed ring-opening polymerization. For a truly sustainable lifecycle of these polymers it is essential to replace the industrially used cytotoxic catalyst tin(II) bis(2-ethylhexanoate) [Sn(Oct)₂ ] with non-toxic alternatives. Here, we report the fastest known robust catalyst in the polymerization of lactide and ?-caprolactone. This zinc guanidine catalyst can polymerize non-purified technical rac-lactide and ?-caprolactone in the melt at different [M]/[I] ratios with fast rate constants, high molar masses, and high yields in a short time, leading to colorless, transparent polymer. Moreover, we report that polylactide and polycaprolactone produced by zinc-guanidine complexes have favorably high crystallinities. In fact, the obtained polylactide shows a more robust degradation profile than its Sn(Oct)₂ -catalysed equivalent due to a higher degree of crystallinity.

SUBMITTER: Hermann A 

PROVIDER: S-EPMC7814670 | biostudies-literature | 2020 Nov

REPOSITORIES: biostudies-literature