Multiscale modeling of polymer materials using a statistics-based micromechanics approach

Abstract

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.

A comparative experimental and molecular simulation study on the mechanical and morphological behaviors of adamantane-based polypropylene composites

“…It is because; the energy equilibration of the molecular structure in the NVE ensemble is irrespective of a simulated time. These time intervals are realistic for engineering experience and yield simulated Young's modulus analogous to modulus of experimental tests which are running on the order of minutes [26,31]. The former is proved by the simulation results of Adnan et al and Stowe et al, which were similar to the experimental values [17,18].…”

“…The predicted values were then compared the experimental ones [26]. Different percentages of ADM (0.5, 1, 2, and 4 wt%), similar to the experimental loadings were added to each group, ergo the effects of molecular weight, chain lengths and chain numbers were evaluated in current study.…”

“…Accordingly, large over estimations have been observed in prediction of the Young's moduli compared to the experimental results [26].…”

Molecular Modeling of the Influence of Crosslink Distribution on Epoxy Polymers

“…This has been discussed in detail elsewhere for thermoplastic systems. 24,25 It is expected that as the number of atoms increases, the scatter will decrease. …”

Atomistic Modeling of Cross-linked Epoxy Polymer

“…With the advancement of computational technology, computational modeling has provided an efficient route to study these polymer resins. [5][6][7][8][9][10][11][12][13][14]4,15 Molecular dynamics (MD) simulations based on the bead-spring model 10,11 and Monte-Carlo simulations based on the bond-fluctuation model 16,8,9 have been used in the last two decades for studying epoxy materials. The beadspring models did not take into account the details of the molecular structures and thus cannot predict the influence of specific groups of atoms on the physical properties.…”