Evidence of Deformation-Dependent Heat Capacity and Energetic Elasticity in a Cross-Linked Elastomer Subjected to Uniaxial Elongation

David Nieto Simavilla, Jay D. Schieber, David C. Venerus

Research output: Contribution to journalArticlepeer-review

2 Scopus citations

Abstract

We present a novel infrared thermography technique to investigate the dependence of heat capacity on deformation in cross-linked polymers. This phenomenon is directly related with the longstanding question of whether or not there is an energetic contribution to the stress in deformed polymers and, in general, to the nonisothermal, viscoelastic behavior of polymer materials. By tracking the temperature evolution of samples heated by a laser, we are able to measure heat capacity changes relative to the equilibrium value in an elastomer subjected to uniaxial extension. We find that the heat capacity increases with elongation in lightly cross-linked cis-1,4-polyisoprene. Remarkably, the onset of heat capacity dependence on deformation is observed at strains similar to those required to achieve finite extensibility. The deviation from the equilibrium value of heat capacity is consistent with an independent set of experiments comparing anisotropy in thermal diffusivity from forced Rayleigh scattering and thermal conductivity from steady-state infrared thermography. Finally, we propose a straightforward thermodynamic analysis of the results based on classical rubber elasticity.

Original languageEnglish (US)
Pages (from-to)589-597
Number of pages9
JournalMacromolecules
Volume51
Issue number2
DOIs
StatePublished - Jan 23 2018
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Organic Chemistry
  • Polymers and Plastics
  • Inorganic Chemistry
  • Materials Chemistry

Fingerprint Dive into the research topics of 'Evidence of Deformation-Dependent Heat Capacity and Energetic Elasticity in a Cross-Linked Elastomer Subjected to Uniaxial Elongation'. Together they form a unique fingerprint.

Cite this