Depolymerization of PLA catalyzed by guanidine-modified microgels.

Microgels are smart catalyst carrier systems, providing good catalyst solubility, accessibility, and compartmentalization, enabling recyclability and improving catalytic performance. In this study, we synthesized functional microgels with controlled number and localization of guanidine units. The microgels were evaluated for their catalytic performance in the methanolysis of polylactide (PLA) and demonstrated high catalytic performance of the guanidine catalyst. In addition, the localization of guanidine in the microgel core led to a faster depolymerization of PLA. The microgel carrier reduced the deactivation of the guanidine units compared to the unsupported guanidine catalyst over several cycles. Our results demonstrate the potential of microgels as catalyst carrier systems that can be used in multiple reaction cycles to improve the implementation of a circular plastics economy and thereby help to reduce plastic pollution in the environment.