Optimization assisted coarse-grained modeling of agglomerated nanoparticle reinforced thermosetting polymers

AA Mousavi and B Arash and R Rolfes, POLYMER, 225, 123741 (2021).

DOI: 10.1016/j.polymer.2021.123741

The interactions between nanoparticles and thermosetting polymers strongly control the overall mechanical properties of polymer nanocomposites. In this study, a coarse-grained model for agglomerated boehmite nanoparticle/epoxy nanocomposites is developed to capture the interactions at the nanoscale. An optimization assisted modified iterative Boltzmann inversion method is proposed to calibrate coarse- grained force fields with two different levels of coarse-graining for an epoxy matrix. Furthermore, the coarse-grained force field of nanoparticles is obtained using the strain energy conservation between coarse-grained models and all-atom systems. The proposed model has the ability to obtain transferable force fields allowing the prediction of material behavior in a broad range of temperatures at significantly lower computational cost compared to all-atom simulations. The applicability of the coarse-grained model to estimate the elastic properties of the polymer reinforced nanocomposites is evaluated using experimental data. It is also shown that the elastic properties of the composites depends on the weight fraction and distribution of nanoparticles. The simulation results reveal that although the modification of epoxy matrices with nano-additives is a crucial factor in enhancing the elastic properties of epoxy matrices, the aggregation of nanoparticles decreases their effectiveness.

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