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Polymer Sciences | ISSN: 2471-9935

October 02-03, 2017 Chicago, USA

International Conference on

Polymer Science and Engineering

Discovery of static shear-elasticity in liquids & melts

Laurence Noirez, Patrick Baroni

and

Philipp Kahl

University Paris-Saclay, France

n the basis of a Maxwell gas model (1867), it has long been suspected that liquids and polymer melts exhibit (shear) elasticity at

sufficiently high solicitation frequencies (MHz or GHz) only. Recent experimental improvements indicate that liquids exhibit

also shear elasticity at very low frequency (0.1 to 10Hz). This finding is of utmost importance, since it means that liquids are no

fully viscous, but possess a weak but finite elastic threshold below which they are solids. The elastic property has been identified at

sub-millimeter scale, both on simple liquids and complex fluids (polymer melts, molecular glass formers, Van der Waals liquids,

ionic liquids, H-bond liquids) pointing out the generic characteristic of this neglected property that invalidates the single molecular

approach of the viscoelasticity. We present the first experiments identifying static shear elasticity in the bulk from unentangled to

entangled polymer melts. In particular, we show how the low frequency shear elasticity and the usual viscoelastic response are related.

The low frequency shear elasticity involves collective processes and has profound implications on how the melt flows, on flow and

surface instabilities, thermodynamics, fluidic transport mechanisms enables to foresee new effects as the cold production or the

spectacular conversion of a liquid melt in a strain-driven optical harmonic oscillator.

Polym Sci, 3:3

DOI: 10.4172/2471-9935-C1-003