(531g) Iterative Modeling of Constraint Dynamics in Discrete Slip-Link Model

Understanding entangled polymer melt relaxation is a long-standing problems in rheology. Single chain, mean-field slip-link models have been used to successfully explain many experimental results for both linear viscoelasticity and under rheological flows. In our Discrete Slip-Link Model the spectrum of relaxation times is found self-consistently from reptation of the probe chain. Unfortunately, previous work has lacked a clear model of the self-consistent relaxation spectrum. In this work we present such a model, where we take relaxation of background chains into account when looking at the relaxation of probe chains. We recognize the fact that destruction by those two processes is coupled. This is more important for star-branched chains, where we show that they require at least two iterations in the mean-field, than it is for linear chains, where one iteration is sufficient. Equipped with the updated model and new, GPU-accelerated code, we find the scaling of the longest relaxation time with molecular weight in symmetric star-branches. We find a substantial difference from tube model predictions.