An analytical molecular mechanics model is developed to obtain the size-dependent elastic properties of crystalline polyethylene. An effective "stick-spiral" model is adopted in the polymer chain. Explicit equations are derived from the Lennard-Jones potential function for the van der Waals force between any two polymer chains. By using the derived formulas, the nine size-dependent elastic constants are investigated systematically. The present analytical results are in reasonable agreement with those from present united-atom molecular dynamics simulations. The established analytical model provides an efficient route for mechanical characterization of crystalline polymers and related materials toward nanoelectromechanical applications.
Bibliographical noteFunding Information:
This work was supported by the Germany Science Foundation project and the Research Council of Norway (MS2MP) Project. The authors would like to thank Professor L. F. Wang, Dr. M. Silani for useful discussions.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)