Relaxation of Anisotropic Thermal Diffusivity in a Polymer Melt Following Step Shear Strain

作     者：David C. Venerus Jay D. Schieber Hadjira Iddir Job D. Guzman Andrew W. Broerman 

作者机构：Department of Chemical and Environmental Engineering and Center of Excellence in Polymer Science and Engineering Illinois Institute of Technology Chicago Illinois 60616 

出 版 物：《Physical Review Letters》 (Phys Rev Lett)

年 卷 期：1999年第82卷第2期

页      面：366-366页

核心收录：

学科分类：07[理学] 0702[理学-物理学] 

主　　题：.shear strain Polymer melt equilibrium value anisotropic thermal ow-induced Following Step following the imposition neutral direction 

摘      要：Forced Rayleigh light scattering is used to examine anisotropic thermal heat conduction due to deformation in a polymeric liquid. Thermal diffusivity is measured in both the flow and neutral directions in a polyisobutylene melt following the imposition of a step shear strain. The thermal diffusivity in the flow and neutral directions increases and decreases, respectively, immediately following the deformation before relaxing to an equilibrium value. Comparison of the difference between measured flow and neutral direction thermal diffusivities with the analogous flow-induced birefringence supports arguments for a proportionality between stress and thermal diffusivity.