Structural Versatility in Slide-Ring Gels: Influence of Co-Threaded Cyclodextrin Spacers

Murakami, T., Schmidt, B. V. K. J., Brown, H. R., Hawker, C. J.
J. Polym. Sci., Part A: Polym. Chem.
55, 1156–1165

We describe a one-pot strategy for the fabrication of novel slide-ring (SR) gels based on supramolecular polyrotaxane structures with cyclodextrin-derived cross-links and additional free cyclodextrin ring spacers co-threaded onto the polymer backbones. Photoinitiated thiol-yne click coupling leads to facile hydrogel fabrication from pseudo-polyrotaxanes prepared in situ from β-cyclodextrin derivatives and bifunctional polyethylene glycol (PEG). The obtained SR gels were characterized by NMR spectroscopy using a polyrotaxane model compound with the ratio of cyclodextrin sliding spacers to PEG backbone controlled by adjusting the feed ratio of the starting materials. This structural tuning leads to dramatic changes in the rheological properties, mechanical properties, and swelling behavior of the SR gels. In addition, the coupling of simple synthetic procedures with enhanced properties offers a versatile approach to novel elastomeric materials.