Associating Polymers in the Strong Interaction Regime: Validation of the Bond Lifetime Renormalization Model

Quantitative understanding of dynamics and viscoelastic properties of associating polymers remains a challenge. This study presents detailed analysis of dielectric and rheological data for telechelic PDMS functionalized with two different end groups, urea that forms multiple hydrogen bonds and carboxylic acid that forms much weaker hydrogen bonds. Analysis of the results revealed that the bond dissociation and bond rearrangement times are similar in the case of strong bonding urea-functionalized samples but are different in the case of weaker interacting carboxylic acid end groups. We demonstrate that these results agree well with the predictions of the bond lifetime renormalization model. The presented results suggest that rheological data can be used for the estimation of activation energy for bond dissociation only in the strong interaction regime and that segmental relaxation should be explicitly accounted for in these estimates, at least, in the systems studied herein.