2004 -06 -02
10 :15 at ML J 21

Anisotropic Thermal Conductivity in Deforming Polymers

David C. Venerus

Illinois Institute of Technology, Chicago, USA

Polymer processing flows involve a strong coupling of mechanical and thermal effects that often have a significant impact on the final properties of the material. Despite this, research on thermal transport in deforming polymer systems has received relatively little attention. Over the past eight years, we have been studying thermal transport in deforming polymers using an optical technique known as Forced Rayleigh Scattering. This sensitive and non-invasive technique is capable of quantitative measurements of anisotropic thermal diffusivity in both static and dynamic (relaxing) polymers subjected to deformations. Results will be presented for polymer melts in shear flows and a cross-linked elastomer in uniaxial extension. Thermal diffusivity data are complemented by measurements of stress and birefringence so that evaluations of the stress-thermal rule, which states the thermal conductivity and stress tensors are linearly related, can be made.