On the consequences of cross-link dissociation in hydrogels

The submersion of a polymer network with a high density of hydrogen bond based cross-links in an aqueous bath results in the formation of a rubber-like hydrogel. The cross-links, which connect chains and maintain the structure of the network, can dissociate as a result of two main factors: (1) the interactions between the hydrogen bonds and the surrounding water molecules and (2) the forces that are exerted on the cross-link from the interconnected chains.

In our new work we derive a model that captures the dissociation of cross-links and its consequences. The model is validated through a series of experiments on poly(methacrylic acid) hydrogel networks dominated by hydrogen bond based cross-links.

The paper, which was recently published in macromolecules, can be found here:

https://pubs.acs.org/doi/full/10.1021/acs.macromol.1c01927