Glass transition temperature influence on crosslinked and entangled polymer interfaces

Abstract

The influence of glass transition temperature (T,) on crosslinked and entangled polymer interfaces was investigated using coarse grained molecular dynamics (MD). A crosslinked polymer interface and an entangled polymer interface were built and the T, for each system were obtained by confining a thin film between two rigid walls. The physical properties of each system above and under T, were compared. The mechanical properties were also explored by pulling the interfaces apart at different temperature. The results are qualitatively agreed with experimental observations. Furthermore, the present results show that, when under tensile loading at temperature higher than T, the entangled interface exhibits strain softening while the crosslinked thin film is still able to show strain hardening. The different performances may due to that, at high temperature, the high mobility of monomers tend to unravel the entangled chain in linear polymer system while in crosslinked system, monomers with high mobility tend to arrest the void and decrease the void propagation. Copyright © 2009 American Scientific Publishers All rights reserved.