Predictions of the linear rheology of polydisperse, entangled linear polymer melts by using the discrete slip-link model

摘要

We present a more efficient way to predict the dynamic modulus of a broadly disperse, entangled polymer melt that uses the discrete slip-link model. Polydisperse blends provide a computational challenge because of the large number of molecular weights that contribute to the modulus. Here, we simulate the order 10 probes to capture the sliding dynamics of chains, but a continuous background to capture constraint dynamics. Contributions of other molecular weights can be interpolated from the simulated probes. Since we use the continuous background, additional probes can be added as needed without re-doing the prior simulations. We show that the method is capable of predicting the modulus well for two different chemistries. Comparison with a simplified double reptation model for a third chemistry shows agreement between the two approaches for frequencies near and below the crossover point of the dynamic modulus even though the distribution is rather narrow. (C) 2018 The Society of Rheology.