Anisotropy of the thermal conductivity in a crystalline polymer:Reverse nonequilibrium molecular dynamics simulationof the δ phase of syndiotactic polystyrene

摘要

The thermal conductivity of the crystalline 8phase of syndiotactic polystyrene has been investigatedby reverse nonequilibrium molecular dynamics simulations. The results are in the expected range.An anisotropy is found for the thermal conductivity, with the component in chain direction being2.5-3 larger than perpendicular to it. Any increase in the density causes an increase also in thethermal conductivity, particularly in the perpendicular directions. As side results, the simulationsconfirm an earlier finding on the force field dependence of the thermal conductivity: The thermalconductivity has a tendency to decrease when the number of active degrees of freedom in the systemis reduced by the introduction of constraints. This dependence is, however, weaker and more erraticthan previously found for molecular liquids and amorphous polymers.