Hydrogels with Dual Relaxation and Two-Step Gel–Sol Transition from Heterotelechelic Polymers

Associating polymers constitute a fascinating class of materials because of the richness in their rheological behavior. Their rheology is mainly dictated by the nature and intrinsic stabilities of the transient associations. Here, we report on the combination of hydrophobic interaction and coordinative bonds through the synthesis of heterotelechelic water-soluble polymers. The characteristics of supramolecular cross-links allow the construction of mechano-responsive hydrogels showing an outstanding "two-step" gel-to-sol transition. Contributions of both supramolecular cross-links are investigated by rotational rheometry while varying the hydrophobic segment length and the type of metal. In this respect, an unprecedented control is gained over the response of multicomponent networks. © 2013 American Chemical Society