(2025) Polymer Degradation and Stability_Pyrolytic conversion of polyimide into carbon-based CO₂ adsorbent with in-situ suppression of toxic byproducts

Lee T.; Kim J.-H.; Choi H.; Kim Y.; Park S.-J.; Kwon E.E.

(1413910) Polymer Degradation and Stability ISSN:  Vol.234 Issue. Article No.111193 DOI: 10.1016/j.polymdegradstab.2025.111193

The polymer's physico-chemical property is reinforced by incorporating an aromatic molecule into the polymeric backbone. However, the persistence of aromatic plastics poses potential hazards against the liberation of toxic compounds. To address this issue, this work proposes a functional use of CO₂ for the pyrolytic conversion of highly aromatised plastics, polyimide, into carbon-based materials while mitigating the toxic aromatic formations. Characterisations of polyimide clarified its exact type and pyrolysis mechanism. Polyimide pyrolysis yielded ≥ 60 wt.% of the char formation. Its surface functionalities revealed superior performance in CO₂ adsorption than the reference materials. However, the production of polyimide-derived adsorbent inevitably generates toxic chemicals. To impede the toxic aromatic formations, CO₂ was chosen as a detoxifying agent. The toxic chemicals liberated from polyimide can be converted into gaseous fuel, CO. This functional role of CO₂ was improved in the presence of a nickel catalyst. CO₂-mediated catalytic pyrolysis led to a 97.7% degradation in toxic chemicals, subsequently resulting in a 3.14-fold increase in CO formation. Therefore, the CO₂-mediated pyrolysis provides insights into the sustainable valorization of aromatic plastic waste into CO₂ adsorbent, simultaneously addressing the environmental issues related to the generation of toxic aromatic pollutants. © 2025 Elsevier Ltd

This work was supported by the National Research Foundation of Korea (NRF) grants funded by the Korean Government (MSIT) (NRF-2023R1A2C3003011 and RS-2024-00342766). Elsevier Ltd