Computing thermomechanical properties of crosslinked epoxy by molecular dynamic simulations

摘要

This paper reports the use of molecular dynamics simulations to study the thermomechanical properties of an epoxy molding compound formed by curing tri/tetra-functionalized EPN1180 with Bisphenol-A. An interactive crosslinking-relaxation methodology is developed to construct the simulation cell. This crosslinking-relaxation methodology allows the construction of highly crosslinked polymer network from a given set of monomers. Based on this computational algorithm, three-dimensional simulation cells can be constructed. By using an existing polymer consistent force-field, several thermomechanical properties of the model epoxy are computed such as the curing induced shrinkage, gelation point, coefficient of thermal expansion, glass transition temperature, Young's modulus and Poisson's ratio. The dependence of these properties on crosslink density and temperature is also investigated. Simulated results are compared with existing theoretical or experimentally measured values when available. Good agreements are observed.