Limit of validity of the stress-optical rule for polystyrene melts: Influence of polydispersity

Clarisse Luap, Marina Karlina, Thomas Schweizer, David C. Venerus

Research output: Contribution to journalArticlepeer-review

18 Scopus citations


Simultaneous measurements of stress and birefringence have been performed during uniaxial extension at constant strain rate of a polydisperse polystyrene melt. In contrast to melts with narrow molecular weight distribution, the relationship between stress and birefringence is found to depend on the temperature and the strain rate in the non-linear region. Failure of the stress-optical rule initiates for lower stress levels, the actual critical stress increasing with the reduced extension rate towards the value measured for quasi-monodisperse systems. In agreement with predictions by van Meerveld [J. van Meerveld, Validity of the linear stress optical rule in mono-, bi- and polydisperse systems of linear entangled chains, J. Non-Newtonian Fluid Mech. 123 (2004) 259-267], this premature failure of SOR occurs within the strain rate regime where only a fraction of the chains of the melt is expected to stretch significantly.

Original languageEnglish (US)
Pages (from-to)197-203
Number of pages7
JournalJournal of Non-Newtonian Fluid Mechanics
Issue number2-3
StatePublished - Oct 1 2006
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • General Chemical Engineering
  • General Materials Science
  • Condensed Matter Physics
  • Mechanical Engineering
  • Applied Mathematics


  • Birefringence
  • Extensional rheology
  • Polydispersity
  • Polystyrene
  • Stress-optical rule


Dive into the research topics of 'Limit of validity of the stress-optical rule for polystyrene melts: Influence of polydispersity'. Together they form a unique fingerprint.

Cite this