Molecular Dynamics Modeling of Epoxy Resins Using the Reactive Interface Force Field

Predictive computational modeling of polymer materials is necessary for the efficient design of composite materials and the corresponding processing methods. Molecular dynamics (MD) modeling is especially important for establishing accurate processing-structure-property relationships for neat resins. For MD modeling of amorphous polymer materials, an accurate force field is fundamental to reliable prediction of properties. Reactive force fields, in which chemical bonds can be formed or broken, offer further capability in predicting the mechanical behavior of amorphous polymers subjected to relatively large deformations. To this end, the reactive interface force field (IFF-R) has been recently developed to provide an efficient means to predict the behavior of materials under these conditions. Although IFF-R has been proven to be consistent for some crystalline organic and inorganic systems, it has not yet been proven to be consistent for amorphous polymer systems. The objective of this study is to use IFF-R to predict the thermomechanical properties of three different epoxy systems and validate them with experimental measurements. The results indicate that IFF-R predicts thermomechanical properties that are consistent with the experiment. Therefore, IFF-R can be used to reliably establish the mechanical properties of polymers on the molecular level for future design of new composite materials and processing methods.