# Stress and neutron scattering measurements on linear polymer melts undergoing steady elongational flow

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DOI: 10.1007/s00397-012-0622-1

- Cite this article as:
- Hassager, O., Mortensen, K., Bach, A. et al. Rheol Acta (2012) 51: 385. doi:10.1007/s00397-012-0622-1

## Abstract

We use small-angle neutron scattering to measure the molecular stretching in polystyrene melts undergoing steady elongational flow at large stretch rates. The radius of gyration of the central segment of a partly deuterated polystyrene molecule is, in the stretching direction, increasing with the steady stretch rate to a power of about 0.25. This value is about half of the exponent observed for the increase in stress value *σ*, in agreement with Gaussian behavior. Thus, finite chain extensibility does not seem to play an important role in the strongly non-linear extensional stress behavior exhibited by the linear polystyrene melt.