Multiscale Modeling of Polymer Materials Using a Statistics-Based Micromechanics Approach

A large number of possible polymer chain conformations exist for a given volume of an amorphous polymer. The prediction of elastic properties of a polymer must therefore consider more than a single combination of chain conformations. A multiscale modeling approach is proposed to predict the bulk elastic properties of polymer materials using a series of molecular models of individual polymer microstates and a statistics-based micromechanical modeling method. The method is applied to polyimide and polycarbonate systems. It is shown that individual microstates can yield a wide range of predicted elastic properties, whereas the consideration of multiple microstates yield predicted properties that more-closely agree with experimentally-determined values of Young’s modulus. Additionally, the upper and lower limits of possible elastic constants are also established based on the consideration of multiple microstates.