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Updated: Jan 16, 2026

Designed for Molecular Recycling: A Lignin-Derived Semi-aromatic Biobased Polymer
Published on: November 30, 2020
Tuning the Degradability Profiles of Polyesters with Indium-Catalyzed Incorporation of Poly(ε-thiocaprolactone)
Joseph Chang1, Chatura Goonesinghe1, Hootan Roshandel2
1Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada.
Abstract:
There are no examples of high molecular weight (>100 000 g/mol) poly(ε-thiocaprolactone) (PtCL), and the mechanism of ε-thiocaprolactone (tCL) polymerization with organometallic complexes has not been investigated. In this work, we demonstrate the synthesis of the highest reported molecular weight PtCL (Mn = 109 000 g/mol) by using a cationic indium thiolate catalyst formed in situ via the addition of benzyl mercaptan. The mechanism of the polymerization is thoroughly investigated and the reaction coordinate is elucidated via computational calculations; the polymerization propagates through a coordination-insertion mechanism. If the PtCL is not isolated during the polymerization, the resulting indium-PtCL macromolecule can be used as an initiator to form copolymers with poly(lactide) (PLA) and poly(ε-caprolactone) (PCL). Incorporating 10% PtCL in these polymers alters their degradation behavior: the hydrolytic degradation period of PLA is reduced by nearly half, while PCL becomes more resistant to hydrolysis.
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