The plastic waste crisis is one of the biggest challenges for mankind. As chemically recyclable and biodegradable materials that can be produced from renewable resources, aliphatic polyesters are considered promising sustainable alternatives for conventional plastics. However, their mass application is impeded by their inferior processability and mechanical properties. Supramolecular polymer modification can provide solutions in this regard, if its limitation to low-molar-mass polymers is overcome and dynamic exchange of supramolecular ligands is tailored appropriately.

We investigated materials based on a sustainable polyester modified with benzene-1,3,5-tricarboxammide (BTA) end groups and blended with a low-molar-mass BTA additive, which we have shown to be a versatile strategy to overcome the molar-mass limitations of supramolecular polymers.^1,2  Due to the helical arrangement of the amide hydrogen bonds around the central benzene stack as a source of frustration, BTA co-assembly results in defined one-dimensional supramolecular columnar aggregates via ditopic multivalent hydrogen bonding. The supramolecular polymer network reinforced with these BTA nanofibrils shows a rubbery behavior at temperatures significantly above the polymer melting point as well as improved melt strength, which is relevant to broaden the processing possibilities. During melt deformation, however, the exchange dynamics of BTA molecules in the columnar stacks is an important feature. Using the chiral BTA derivative N,N’,N’’-tris((S)2-methylbutyl)benzene-1,3,5-tricarboxamide (SB), we can tailor the exchange dynamics to be fast enough to allow for a reorganization of the supramolecular aggregates but slow enough to prevent materials flow. This leads to melt-processing opportunities that are not possible for the pristine polymer. Our results show the importance of supramolecular motif design for properties and performance of the final material.

[1] Daniel Görl; Shuichi Haraguchi; Yevhen Hryshunin; Sophia Thiele; Giorgia Scetta; Alexandre Simula; Matthieu Wendling; Oguzhan Oguz; Nicolas Candau; Torne Tänzer; Marianne Liebi; Christopher J. G. Plummer; Holger Frauenrath, Nature Communications, 2025,16, 217-230.

[2] Sophia Thiele; Michael Giffin; Matthieu Wendling; Daniel Görl; Christopher J. G. Plummer; Holger Frauenrath, Organic Chemistry Frontiers, 2025, 12, 5395-5413.