# Efficient Microwave‐Assisted Hydrolytic Recycling of Poly(L‐Lactic Acid)

## TL;DR

This paper presents a new, efficient method to recycle a biodegradable plastic using microwave-assisted chemical reactions with a zinc catalyst.

## Contribution

The study introduces a scalable, energy-efficient, solvent-free microwave-assisted hydrolysis method for recycling PLLA into lactic acid.

## Key findings

- Microwave-assisted hydrolysis significantly improves reaction rate and selectivity compared to conventional heating.
- The method allows direct conversion of postconsumer PLLA into lactic acid under mild conditions without solvents or pressure.
- The zinc catalyst enables efficient and green chemical recycling of PLLA with low waste generation.

## Abstract

Poly(L‐Lactic acid) (PLLA) is a bio‐based and biodegradable thermoplastic polymer widely recognized as a leading sustainable alternative to conventional petroleum‐based plastics. While its environmental benefits are well established, PLLA faces challenges in end‐of‐life management due to its slow degradation in natural conditions and the harsh requirements of industrial composting. This study introduces an efficient chemical recycling strategy for PLLA based on hydrolysis reactions performed both in solution and under solvent‐free conditions, catalyzed by a homoleptic phenoxy‐imine pyridine zinc complex. Both conventional and microwave‐assisted heating methods were evaluated. Hydrolysis in solution exhibited consistent degradation rates across various solvents, irrespective of the heating technique. In contrast, microwave‐assisted heterogeneous hydrolysis significantly improved both reaction rate and selectivity. Notably, this process enables the direct conversion of postconsumer PLLA products into lactic acid under mild reaction conditions, without the need for additional solvents or pressure build‐up. The catalytic approach demonstrates a scalable, energy‐efficient pathway for closing the PLLA lifecycle, offering a viable solution for industrial monomer recovery with low waste generation.

Microwave‐assisted hydrolysis of poly(lactic acid) promoted by a zinc catalyst. A highly efficient procedure performed under mild reaction conditions and in the absence of solvents aligning with green chemistry principles.© 2026 WILEY‐VCH GmbH