New polymers, properly designed for end-of-life and efficiently formed from renewable carbon, are key to the transition to a more sustainable, circular plastics economy. Promising strategies towards polymers that are chemically recyclable to the monomer (CRM) include ring-opening polymerization (ROP) of cyclic monomers, however, reported monomers typically lack a reasonable production route from biobased starting materials.^1–3 We recently developed a synthesis route towards renewable, tricyclic oxanorbornene lactone monomers produced from readily available bioderived furans, which undergo exceptionally rapid and controlled ROP.^4,5 The polyester was formed in low dispersity and with controllable molecular weight (up to 76.8 kg mol⁻¹), and exhibits a high T_g of 120 °C. The orthogonal olefin and lactone functionalities offer access to a wide range of promising materials, as showcased by post-polymerization modification (PPM) by olefin hydrogenation, increasing polymer thermal stability by over 100 °C. Next to rapid hydrolytic degradation and solvolysis, the polyester also cleanly undergoes CRM, in line with its favorable ceiling temperature (T_c) of 73 °C. PPM hydrogenation lowers the T_c by 94 °C, showcasing that subtle changes in the monomer structure strongly affect successful (de)polymerization. Establishing structure-property relations such as these is key for designing the next generation of recyclable plastics.

References:

1. C. M. Plummer, L. Li and Y. Chen, Macromolecules, 2023, 56, 731–750;
2. X. Tang and E. Y. X. Chen, Chem, 2019, 5, 284–312;
3. G. W. Coates and Y. D. Y. L. Getzler, Nat. Rev. Mater., 2020, 5, 501–516;
4. R. C. Cioc, E. Harsevoort, M. Lutz and P. C. A. Bruijnincx, Green Chem., 2023, 25, 9689–9694;
5. E. Harsevoort, R. C. Cioc, M. Lutz, A. Thevenon and P. C. A. Bruijnincx, J. Am. Chem. Soc., 2024, 146, 34628–34637.

Eva Harsevoort has been conducting her PhD research since 2022 in the Organic Chemistry and Catalysis group, focusing on biobased and recyclable plastics. After obtaining a BSc in Chemistry at the Radboud University and one year as research scientist at Synthon Biopharmaceuticals, she did her MSc in Nanomaterials Science at Utrecht University, which included an internship at UC Davis.