Post‐Synthetic Amide Insertion Into Polyethylenes Augments Diverse Physical Properties and Enables Branching‐Dependent Recyclability

Post‐Synthetic Amide Insertion Into Polyethylenes Augments Diverse Physical Properties and Enables Branching‐Dependent Recyclability

Advanced Functional Materials

10.1002/adfm.202513841

https://doi.org/10.1002/adfm.202513841

Albert Ong, Jaime J. M. Pang, Wei Wei Loh, Jerald Y. Q. Teo, Ke Li, Xue Qi Koh, Tristan T. Y. Tan, Lewis Queh, Zibiao Li, Jason Y. C. Lim

Plastics, polyolefins, skeletal editing, upcycling, circularity

29 August 2025

Ong, A., Pang, J. J. M., Loh, W. W., Teo, J. Y. Q., Li, K., Koh, X. Q., Tan, T. T. Y., Queh, L., Li, Z., & Lim, J. Y. C. (2025). Post‐Synthetic Amide Insertion Into Polyethylenes Augments Diverse Physical Properties and Enables Branching‐Dependent Recyclability. Advanced Functional Materials. Portico. https://doi.org/10.1002/adfm.202513841

Polyethylenes (PEs) possess unreactive saturated hydrocarbon backbones, which make chemical recycling highly challenging, even at high temperatures. The insertion of strongly‐hydrogen‐bonding amide linkages into the PE backbone can potentially confer recyclability via amide cleavage and reformation, whilst simultaneously bringing about new material properties for functional upcycling. Herein, it is demonstrated that in‐chain amide insertion can be performed under a variety of reaction conditions, including the usage of p‐cymene as a bioderived green solvent, with common and low‐cost reagents, on both high‐density (HDPE) and low‐density PEs (LDPE). Approximately 1 amide bond/100 ethylene repeating units can enhance not only the polymers’ tensile properties, but also elicit an unexpected increase in surface hydrophobicity and solid‐state clusteroluminescence that is absent in the parent PEs. Additionally, the hitherto‐overlooked importance of PE structure is uncovered in its chemical recyclability. While low‐branching amide‐containing HDPE could be hydrolysed and reformed for three cycles at ≤150 °C without compromising their tensile properties, attempted chemical recycling of highly‐branched LDPE formed a thermoset‐like crosslinked polymer with greatly enhanced ductility. These findings showcase amide‐insertion as a versatile means to access new functional applications that are originally inaccessible to PEs without requiring additives, with branching‐dependent influences on chemical recyclability for circular polymeric materials design.

Publisher Copyright

This research / project is supported by the Agency of Science, Technology and Research (A*STAR) - RIE2025 Manufacturing, Trade and Connectivity (MTC) Programmatic Funding
Grant Reference no. : M22K9b0049

This is the peer reviewed version of the following article: Ong, A., Pang, J. J. M., Loh, W. W., Teo, J. Y. Q., Li, K., Koh, X. Q., Tan, T. T. Y., Queh, L., Li, Z., & Lim, J. Y. C. (2025). Post‐Synthetic Amide Insertion Into Polyethylenes Augments Diverse Physical Properties and Enables Branching‐Dependent Recyclability. Advanced Functional Materials. Portico. https://doi.org/10.1002/adfm.202513841 , which has been published in final form at [Link to final article using the DOI]. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited.

https://oar.a-star.edu.sg/communities-collections/articles/22208

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Institute of Materials Research and Engineering