Kinetic, products distribution, and mechanism analysis for the pyrolysis of polyglycolic acid toward carbon cycle

Present investigation was aimed at exploring the pyrolysis kinetics, product distribution, and mechanisms of polyglycolic acid (PGA) via experiments and reactive force field molecular dynamic (ReaxFF-MD) simulations to establish a foundation for the recycling of raw materials in the future. The kinetic analysis presented that the PGA pyrolysis belonged to the contracting cylinder model with the apparent activation energy ranged from 138.1 to 141.7 kJ/mol. The gaseous product was determined to contain carbon dioxide, carbon monoxide, and formal-dehyde through TG-IR and TG-MS, and Py-GC/MS results showed that the yield of glycolide reached the maximum at 450 degrees C. The ReaxFF-MD simulation revealed that the initial pyrolysis pathway for PGA was the cleavage of alkoxy bond, followed by C-C bond and acyloxy bond with the generation of carbon dioxide, carbon monoxide, formaldehyde, and ethenone. This study would provide comprehensive experiment data and mean-ingful guidance for recycling PGA to achieve a closed-loop economy.

Automated summary

The present study investigated the pyrolysis kinetics, product distribution, and mechanisms of PGA using experiments and simulations. The findings reveal the pyrolysis pathway of PGA and provide guidance for its recycling.