Reëntanglement Dynamics in Polymer Melts Can Be Explained by Fast Dangling End Retraction without Resorting to Nonuniversality

Recent molecular dynamics simulations of entangled polymer melts suggest that chains reëntangle on the (Rouse) time scale of chain retraction, rather than on the longest, disengagement relaxation time, upon cessation of flow [O’Connor et al. Macromolecules 2019, 52, 8540−8550]. Inspired by these results, it has been suggested by using a tube model that reëntanglement kinetics are chemistry specific [Dolata et al. ACS Macro Lett. 2024, 13, 896−902]. Here we argue that their conclusions arise from interpreting simulations with a model that does not have a sufficiently detailed level of description. We employ the discrete-slip-link model, which is more detailed and so contains important fluctuations. We show that this universal level of description can describe the results without resorting to chemistry specificity. Our results suggest that a significant amount of reëntanglement happens on the Rouse time, which obscures the fact that it finishes only on the disengagement time, resolving the apparent paradox.