Energy Renormalization for Coarse-Graining Polymers Having Different Segmental Structures

Published

April 19, 2019

Author(s)

Jack F. Douglas, Wenjie Xia, Nitin K. Hansoge, Wen-Sheng Xu, Sinan Keten, Frederick R. Phelan Jr.

Abstract

We apply the recently developed energy renormalization (ER) method to coarse-graining representative polymer melts having a relatively low, intermediate and high degree of glass fragility, i.e., polybutadiene, polystyrene, and polycarbonate, respectively, as quantified by the relative strength of the temperature dependence of their dynamic properties. Since the preservation of the polymer segmental dynamics under coarse-grained (CG) modeling and over a wide range of temperatures is a significant challenge from both theoretical and practical standpoints, this comparative study provides a stringent test of the generality of the ER methodology. We find that the ER method applies equally well for these polymers representing broad classes of glass-forming polymer materials where the ER parameters are derived by the constraint that the Debye-Waller factors and overall fluid densities of the all-atomistic and coarse-grained models are consistent at all temperatures. Furthermore, we gain valuable insights into the ER method by applying the method formally to the theoretical predictions of the generalized entropy theory (GET) of glass formation for a model flexible polymer and its CG analog, where we obtain consistent results with our simulations. Our findings demonstrate the effectiveness and applicability of the ER approach towards building a multi-scale temperature transferable modeling framework for polymers having different segmental structures, and elucidate the critical roles of dynamic properties, such as fragility, and degree of coarse-graining in influencing the CG modeling.

Citation

Science Advances

Pub Type

Journals

Keywords

coarse-graining, energy renormalization, temperature transferability, polymer melt dynamics

Citation

Douglas, J. , Xia, W. , Hansoge, N. , Xu, W. , Keten, S. and Phelan, F. (2019), Energy Renormalization for Coarse-Graining Polymers Having Different Segmental Structures, Science Advances (Accessed April 25, 2024)