Structure and Morphology of Semi-Crystalline Polymer Interphases - Molecular simulation of 'realistic chains'.
Abstract
The structure and morphology of semi-crystalline polymer interphases has been subjected to intensive study due to their importance in mechanical and thermal properties of polymers. However there remain several unresolved issues with respect to the dissipation of order and chain flux between the crystal and amorphous regions. In this paper we seek to address the structural and thermodynamic properties of constrained polymer interphases by equilibrium molecular simulation of 'realistic' polymer chains. Robust off-lattice Monte Carlo moves involving cutting and splicing chains and conventional displacement of atoms on polymer chains are employed in sampling interphase structures. In the process, atomistically detailed structures replete with proper limiting equilibrium distribution of tight and loose chain folds and tie chains are generated. The simulations capture the gradient in density and order across the interphase region. Results for polymer chains with realistic potentials and for completely flexible chains indicate that there is a dramatic change in the degree of both loose and tight folding in local equlibrium. The interphase thickness predicted by the simulations are compared with experimental results for poly(ethylene). The effect of molecular weight on the structure and morphology of the interphase will also be presented.
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- March 1998
- Bibcode:
- 1998APS..MAR..L804B